Columns, Supplies, and Standards Knowledgebase

Version 24

    Here is a list of the currently available Knowledgebase for Agilent's consumable products in the Chemistries and Supplies Division (CSD) in the following categories:

    Filaments and Ion Sources

    QuestionQ001What are the steps to increase filament life?
    QuestionQ002What are the steps to troubleshoot a broken filament?
    QuestionQ003What filaments are supported on the MSD?
    QuestionQ004What is the procedure to maintain the MS Filaments?

    Gas Management

    QuestionQ005Are there any concerns about the temperature of the gas or the surroundings when using the Agilent G6691A Flowmeter??
    AnswerA005The gas flow can be any temperature. The storage temperature for the Flow Meter will  affect accuracy. The unit should be stored at temperatures under 50 degrees  Celsius. A sticker is attached to each unit to gauge if the Flow Meter has gone outside the recommended temperature range while in storage or transit.  If that happens, the sticker on the unit will turn black. The Flow Meter should then be sent back as a DEFOA and a replacement sent to the  customer.
    QuestionQ006Can I recycle my gas traps?
    AnswerA006Generally no, accept for Renewable Gas Purification Systems
    QuestionQ007Can I use rechargeable batteries in the Agilent G6691A Flowmeter?
    AnswerA007Yes, but the Flow Meter won’t read full battery power; cell voltage with the rechargeable batteries will be less than with alkaline batteries.
    QuestionQ008Can it measure corrosive gases (e.g. ammonia)?
    AnswerA008No. This is not approved by Agilent. If measured, the warranty is invalidated and Agilent can’t guarantee the future performance or accuracy of the Flow Meter. The Flow Meter is designed for dry, noncorrosive gases.
    QuestionQ009Can the Agilent G6691A Flowmeter measure corrosive gases (e.g. ammonia)?
    AnswerA009No. This is not approved by Agilent. If measured, the warranty is invalidated and Agilent can’t guarantee the future performance or accuracy of the Flow Meter. The Flow Meter is designed for dry, noncorrosive gases.
    QuestionQ010Does the cartridge for the Agilent G6691A Flowmeter have a shelf life?
    AnswerA010The recommended shelf life is one year plus one additional year of use.  The box it ships in has a temperature sticker stating if the cartridge is stored at a temperature above 130 F that could damage the components.
    QuestionQ011Does the temperature of the gas affect the measurement on the Agilent G6691A Flowmeter?
    AnswerA011Yes.  For a given mass flow rate the volumetric flow rate of a gas vary with the  gas temperature and pressure. For a given mass flow rate the volumetric flow  rate will increase with an increase in gas temperature and a decrease in gas pressure. As the ADM Flow Meter is a volumetric flow meter it will report the  flow rate as it is measured.  In mass flow mode the temperature and  pressure are taken into account and the flow rate is displayed as if the gas temperature was 0 °C and 1 atm of pressure.
    QuestionQ012How do I download the calibration certificate for the Agilent G6691A Flowmeter?
    AnswerA012Consult the Flow Meter Operating Instructions
    QuestionQ013How do I get a replacement hose for the Agilent G6691A Flowmeter?
    AnswerA013The part number for the replacement hose is G6692-68000.
    QuestionQ014How do I know when to change my GasClean Filers?
    QuestionQ015How do I update the firmware on the Agilent G6691A Flowmeter?
    AnswerA015Consult the Flow Meter Operating Instructions
    QuestionQ016How many points are on the Certificate of Calibration for the Agilent G6691A Flowmeter?
    AnswerA016The unit is calibrated using 12 points and verified at 14 flow rates, which are show on the certificate.  The verification points are: 0,0.5,1.0,5.0,10,50,100,300,400,500,601,700,750 ml/min.
    QuestionQ017I have a Agilent G6691A Flowmeter.  What do I do with the spare cartridge after it is out of calibration?
    AnswerA017The consumed cartridge can be disposed of per your local requirements for electronic waste.  A new cartridge can be ordered online at
    QuestionQ018I have a Gas Clean filter, what does it mean if the indicator is changing colors from the bottom up? Top down?
    QuestionQ019If I cut the hose on the Agilent G6691A Flowmeter?, will that affect my measurements?
    AnswerA019Changing the hose length will affect your measurements. The Flow Meter is calibrated with the hose.
    QuestionQ020Is it safe to measure hydrogen with the Agilent G6691A Flowmeter?
    AnswerA020Yes. Agilent advises to purge with an inert gas after measuring hydrogen.
    QuestionQ021Is the calibration start date for the Agilent G6691A Flowmeter what is listed electronically inside the flowmeter or is it what is listed on the calibration certificate shipped with the flow module?  How do we justify this with our auditors when they ask
    AnswerA021It is  what is listed electronically inside of the flowmeter. The flow cell calibration is valid for one  year after installation. If the customer is unable to follow this guideline  due to their local procedures, they will need to replace the cartridge based on the calibration certificate date rather than the Agilent recommended date  provided on the screen.
    QuestionQ022Is there a user manual supplied with the Agilent G6691A Flowmeter?
    AnswerA022The only documentation provided with the flowmeter is the calibration certificate and the Quick Start Guide. The user manual can be found on the product page on
    QuestionQ023Is there an AC Adapter for the Agilent G6691A Flowmeter?
    AnswerA023You can use the USB cable but will need to purchase the appropriate plug for the cord. The unit can be powered by the USB, but it will not recharge the batteries.
    QuestionQ024Is there instructions on how a measurement is done for split ratio using the Agilent G6691A Flowmeter?
    AnswerA024We developed a detailed Troubleshooting Guide that details this measurement at
    QuestionQ025Is there instructions on how a measurement is done for split ratio?
    AnswerA025We developed a detailed Troubleshooting Guide that details this measurement at
    QuestionQ026My Flow Meter OLED screen reads “Error code X.” What does that mean?
    AnswerA026All error codes are listed in the Operation Manual for the Flow Meter.
    QuestionQ027The Agilent G6691A Flowmeter is supposedly able to be powered by both batteries as well as through USB. Why doesn’t the USB cable come with a power adaptor?
    AnswerA027The USB  adapter is intended for connecting to the PC for updating the firmware or  accessing the digital version of the calibration certificate. The Flow Meter is powered by 3 AA batteries. The USB port can be used to continuously power  the device, but it is not able to recharge the AA batteries. The USB-Power adapter is not required for the device and is not supplied. 3 AA batteries  are supplied with the flowmeter.
    QuestionQ028The Agilent G6691A Flowmeter OLED screen reads “Error code X.” What does that mean?
    AnswerA028All error codes are listed in the Operation Manual for the Flow Meter.
    QuestionQ029The manual in softcopy states that the Agilent G6691A Flowmeter can communicate to our computer via a USB cable. Where is the driver to support the USB connection?
    AnswerA029See the ADM Flowmeter PC Connection Guide
    QuestionQ030There is a temperature sensitive sticker applied to the Agilent G6691A Flowmeter box. What is it for?
    AnswerA030The temperature sensitive sticker is intended for use during shipment. The Flowmeter is designed with the same operating and storage temperature limits as the GC.
    QuestionQ031We activated the Agilent G6691A Flowmeter and inserted the new cartridge, but the display on the cartridge is showing a different time and date. Is this following USA timing?
    AnswerA031The Flow Meter is set on Coordinated Universal Time (UTC). The intent of the timer is to indicate one year of use from the installation dates rather than a specific start date. This satisfies the needs of many compliant departments worldwide.
    QuestionQ032What are the part numbers for the Agilent G6691A Flowmeter?
    AnswerA032G6691A is the Flow Meter, which includes the first cartridge.  G6692A is the replacement cartridge.
    QuestionQ033What are the part numbers of the adaptors for the detectors for the Agilent G6691A Flowmeter?
    AnswerA0335190-9576 is the FID Adapter for Flow Meter 5190-9577 is the NPD Adapter for Flow Meter 5190-9578 is the TCD Adapter for Flow Meter
    QuestionQ034What are the ranges of operating conditions for the Agilent G6691A Flowmeter?
    AnswerA034Flow Range: 0 to 750 ml/min Accuracy: 0-500ml/min  +- 2% of reading or +- 0.2 ml/min whichever is greater, 501-750 ml/min +-3% of reading Operating temperature range: 0C to 45C Power: 3 AA batteries or USB power
    QuestionQ035What do I do with the spare cartridge after it is out of calibration?
    AnswerA035The consumed cartridge can be disposed of per your local requirements for electronic waste.  A new cartridge can be ordered online at
    QuestionQ036What gas line traps are recommended for the MSD's?
    QuestionQ037What gas traps are recommended for Agilent GC?
    QuestionQ038What happens if I cover the vents on top of the Agilent G6691A Flowmeter?
    AnswerA038If the vents are covered on top, the Flow Meter will not read accurately and the internal components may be damaged, requiring the cartridge to be replaced.
    QuestionQ039What happens if the Agilent G6691A Flowmeter overflows?
    AnswerA039If this does occur, the Flow Meter will log the date and time of when that occurred. A replacement cartridge will need to be ordered for the Flow Meter.
    QuestionQ040What indicates the need To change the gas purifiers?
    QuestionQ041What is the maximum flow rate for the Agilent G6691A Flowmeter?
    AnswerA041The limit is 900uL per minute. If the customer hears a crunching noise, the transducer has been broken and the cartridge needs to be replaced.
    QuestionQ042When I purchase the Agilent G6691A Flowmeter does it come with a flow cartridge?
    AnswerA042Yes.  The replacement cartridge is not needed at time of purchase unless an extra cartridge is wanted as a spare.
    QuestionQ043When we opened the box for the Agilent G6691A Flowmeter we noticed that the hose was not connected to the cartridge. The flowmeter is calibrated with the hose, so doesn’t it mean that the hose should already come pre-installed?
    AnswerA043The  tubing used in calibration is identical to the tubing shipped separately in  the box. A replacement part number is  available if the tubing is damaged. The intent of this warning statement is  to advise the customer against altering the tubing which will impact the calibration.

    GC Columns

    QuestionQ044After replacing the column, what does error "Vacuum Pump is Not Ready" indicate?
    QuestionQ045Can a Guard Column Be Utilized?
    QuestionQ046Can graphite/polyimide ferrules be used with Pre-swaging tool
    QuestionQ047Can I order the old column cage design?
    QuestionQ048Can I order these improved columns using the current part number?
    QuestionQ049Can modules be connected To each other?
    QuestionQ050Column Installation Pre-Swaging Tool - metal ferrules
    QuestionQ051Do I need a transfer line module for each column module?
    QuestionQ052Do you have a GC Column Cross-Reference guide?
    QuestionQ053Do you have information on GC Column test standards?
    QuestionQ054Does the new design affect the column performance? Can I use the same method?
    QuestionQ055GC Column Cross-Reference guide
    QuestionQ056GC Column Test standards
    QuestionQ057How do column modules connect to transfer line modules, the oven, the injector and detector?
    QuestionQ058How do I select a Split/Splitless liner?
    QuestionQ059How many modules can be operate simultaneously with different temperature programs?
    QuestionQ060How much force is needed to pre-swage a ferrule?
    QuestionQ061How should customer condition a PLOT column before use?
    QuestionQ062I just received 2 columns that look very different. What should I do?
    QuestionQ063Since this is a replacement, why are the part numbers different for the improved columns?
    QuestionQ064Spots on PLOT columns - will they affect the performance?
    QuestionQ065Spots on PLOT columns and will they affect the performance?
    QuestionQ066What about the QC test? Will this be different?
    QuestionQ067What are the possible causes for ghost peaks or carryover?
    QuestionQ068What are the possible causes for peak tailing?
    QuestionQ069What are the possible causes of no peaks being observed?
    QuestionQ070What are the Possible Causes of Peak Tailing?
    QuestionQ071What are the possible causes of peaks being larger and eluting earlier?
    QuestionQ072What are the possible causes of peaks of interest showing up in blank runs?
    QuestionQ073What are the possible causes of resolution loss and retention time shift after installing a new column?
    QuestionQ074What are the Possible Causes of Resolution Loss and Retention Time Shift After Installing a New Column? - 5890 GC
    QuestionQ075What are the practical differences in the 3" (small) and 5" (standard) formats?
    QuestionQ076What are the procedures for conditioning capillary GC columns?
    QuestionQ077What are the steps to best troubleshoot column bleed?
    QuestionQ078What are the steps to condition a Capillary Column?
    QuestionQ079What are the steps to determine if a sample is causing damage to a capillary column?
    QuestionQ080What are the Steps to Install a Capillary Column in the PCOC Inlet?
    QuestionQ081What are the steps to install a capillary column into a TCD?
    QuestionQ082What are the steps to minimize and monitor column bleed?
    QuestionQ083What are the steps to minimize problems with water injections on capillary columns?
    QuestionQ084What are the steps to obtain maximum performance when using a deans switch with PLOT columns?
    QuestionQ085What are the steps to reduce peak fronting?
    QuestionQ086What are the steps to troubleshoot a retention time shift?
    QuestionQ087What are the steps to troubleshoot baseline instability?
    QuestionQ088What causes peak fronting?
    QuestionQ089What causes peak tailing?
    QuestionQ090What causes the spots on PLOT columns and does it affect the performance of the columns?
    QuestionQ091What columns and flow rates are acceptable for proper operation of the MSD?
    QuestionQ092What happens if I order using the current GC Column part number?  Will I receive the improved columns?
    QuestionQ093What is "LTM" Technology?
    QuestionQ094What is the correct distance a column should be installed in the GC Inlet?
    QuestionQ095What is the Maximum Operating Temperature for a Module?
    QuestionQ096What is the procedure for installing a GC column in to GC-FID, GC-TCD, µECD and/or GC-MSD?
    QuestionQ097What types of GC Columns can be used?
    QuestionQ098What would happen if I don't install the thermal shield?
    QuestionQ099What’s the difference between the standard columns and the improved versions?
    QuestionQ100Why are peaks of interest showing up in blanks?
    QuestionQ101Why are the peaks smaller than expected (poor sensitivity)?
    QuestionQ102Why are there unwanted (ghost) peaks in the 7890A GC chromatogram?
    QuestionQ103Why do I occasionally get a PLOT column with what looks like a spot or spots in the column? What causes this? Will this affect the performance of the column?
    AnswerA103The  spots you are seeing are small voids in the stationary phase coated inside of the tubing. It is normal to have some  voids in the phase coating of PLOT columns. The columns are individually tested and verified to exhibit the  correct chromatographic performance. Agilent guarantees the reliability and  performance of our products with a 90-day warranty for all of our GC columns.
    QuestionQ104Why does my column look different?
    QuestionQ105Why does the instrument have trouble tuning after a column replacement?
    QuestionQ106Why improve HP-INNOWax and CP-Wax 52 CB columns?
    QuestionQ107Why is the effective internal diameter of the PLOT Column necessary when using the deans switch?
    QuestionQ108Will I experience any selectivity difference with the new GC Column?
    QuestionQ109Will the EZ-Grip fit the updated column cage?
    QuestionQ110Will the improved columns fit my regulated method?


    QuestionQ111What information is included on the CofA?
    AnswerA111A Certificate of Analysis is shipped with each standard detailing the specific MW characteristics for each vial.
    QuestionQ112Where do I find the Certificate of Analysis for my product?
    QuestionQ113Where do I find the Material Safety Data Sheet (MSDS) for my product?

    Inlets and Liners

    QuestionQ114What are the steps to chemically deactivate injection liners?
    QuestionQ115What are the steps to clean the GC injection port liner?
    QuestionQ116What indicates the liner or glass wool need replacement?
    QuestionQ117What indicates the need to change the septum or liner?
    QuestionQ118What is the appropriate amount of glass wool in a liner?


    QuestionQ119Are there any performance compromises with multi-element lamps?
    QuestionQ120Are there storage guidelines for AA lamps?
    AnswerA120Hallow Cathode Lamps do not have an expiry date or shelf life. The lamp is totally sealed (like a light bulb) so even though it may be in storage for a while, we don’t expect to see any degradation in performance. You can check the lamp by checking the gain setting located on the lamp optimization screen in the software.  If necessary check for an emission peak at the appropriate wavelength using a lamp emission scan. You should keep a record of the gain setting and confirm that it does not change significantly from the last test. A faulty lamp will show a glow from the cathode - but the gain setting will be very high - and the instrument will report an error message (either low lamp energy or it may show a "peak not found" error). There is also an AA at Work publication (application note) that may be a useful reference as it provides more detail to help users learn more about the design characteristics and operation of using hollow cathode lamps and deuterium lamps.
    QuestionQ121Can all lines be used in multi element lamps without interference?
    QuestionQ122Can spectral interferences be overcome?
    QuestionQ123Do any lamps have solid cathodes?
    QuestionQ124Do other elements in the cathode affect the lifetime?
    QuestionQ125Does the flickering glow around the anode mean that the lamp is faulty?
    QuestionQ126How do I dispose of my hallow cathode lamp?
    AnswerA126You can dispose of old or used hollow cathode lamps in accordance with local EPA or Government regulations for regular vacuum lamps (or globes). Hollow cathode lamps contain small quantities of chemicals (usually less than 5 grams per lamp) and the lamps should be disposed of in a responsible manner because of these chemicals.
    QuestionQ127How do you know when a lamp is worn out?
    QuestionQ128How much fill gas is added?
    QuestionQ129Is there a compromise in intensity with the Ag/Cd/Pb/Zn or Al/Ca/Mg multi elements lamps?
    QuestionQ130What additional information is available on lamp construction and operation?
    QuestionQ131What are the steps to perform a DAD intensity test using the ChemStation?
    QuestionQ132What are the steps to perform a DAD wavelength calibration test using a control module?
    QuestionQ133What are the steps to perform a DAD wavelength calibration test using the ChemStation?
    QuestionQ134What are the Steps to Perform a FLD Dark Current Test using the ChemStation? - 1100 Series LC
    QuestionQ135What are the steps to perform a FLD lamp intensity test using the ChemStation?
    QuestionQ136What are the steps to reset the lamp hours on a DAD, MWD or VWD?
    QuestionQ137What are the typical % Gain or EHT values for hollow cathode lamps?
    QuestionQ138What are the typical life times of a cathode lamp?
    QuestionQ139What are typical results from a Arsenic (As) hollow cathode lamp drift test?
    QuestionQ140What causes baseline noise and drift after replacing the DAD lamp and flow cell?
    QuestionQ141What indicates the FLD lamp is on?
    QuestionQ142What is the approximate life of UV Detector lamps?
    QuestionQ143What is the approximate lifetime of UV detector lamps?
    QuestionQ144What is the black spot?
    QuestionQ145What is the purpose of the fill gas?
    QuestionQ146What type of testing do lamps undergo during production?
    QuestionQ147Why do lamps wear out?
    QuestionQ148Why does a new lamp look used?
    QuestionQ149Why does my hallow cathode lamp looked burned inside?
    AnswerA149In the lamp purification and processing operation, the polarities of the cathode and the anode in the lamp are reversed so that the zirconium anode now becomes the cathode. This subjects the zirconium anode to ion bombardment. During this discharge a small amount of the zirconium anode material is vaporized and deposited on the inside envelope of the lamp. This is the dark film visible on the glass envelope near the anode. Zirconium is a very active “getter” for impurity gases such as oxygen and hydrogen, and this discharge serves to purge the lamp of these impurity gases. That is, this activated film of zirconium will absorb any impurity gases that may have escaped the previous purification stage.  This “black patch” that is visible on the inside of the lamp ensures that the fill gas is free of impurities and contributes to the long shelf life of Agilent lamps – and also ensures continued spectral purity throughout the life of the lamp. Finally the lamp is then filled with spectroscopically pure gas and sealed. Processed lamps are then operated for several hours prior to testing. The extended processing cycle and use of specially pure materials ensures dependable performance from Agilent hollow cathode lamps. For further details on the features and characteristics of the hollow cathode lamp, please refer to the Agilent Application Note titled “Features and Operation of Hollow Cathode Lamps and Deuterium Lamps” available from the Agilent literature library on the Agilent website
    QuestionQ150Why treat the cathode?

    LC Columns

    QuestionQ151Agilent AdvanceBio Peptide Mapping Columns Specifications
    QuestionQ152Agilent Bio IEX Column Specifications
    QuestionQ153Agilent Bio SEC-3 Column Specifications and Options
    QuestionQ154Agilent Bio-Monolith Column Specifications
    QuestionQ155Agilent ZORBAX Bio SEC-5 Column Specifications and Options
    QuestionQ156Bio LC Column User Guides
    QuestionQ157Can I really effectively use these very short columns on my HPLC instrument?
    AnswerA157Yes,  you can. For columns of 3.0 mm i.d. and above, no instrument adjustments are necessary. For gradient separations with 2.1 mm and 1.0 mm i.d. columns the  ideal HPLC is a high-pressure mixing instrument — like the Agilent 1100 HPLC  with the binary pump, because it minimizes the gradient delay volume. Using a low volume mixer and the injector by-pass (or micro-injector) further  minimize gradient delay volume. Narrow i.d. tubing and a low volume detector  flow cell are preferred but not necessary. These changes are easy to make and allow you to effectively use columns as small as the 2.1 x 30 mm columns or  even the 2.1 x 15 mm columns
    QuestionQ158Do you think that using toluene as a standard for measuring GPC column efficiency is appropriate?
    AnswerA158Yes.  Conditions for this evaluation are chosen so that the small molecule toluene does not interact with the packing, but diffuses through all the pores of the  GPC column packing. By conducting the experiment in this way, the width of  the eluting peak is a function of the particle size of the packing and how well the column bed is packed. That's what you want to know when you are  measuring efficiency. This sample is commonly used and recommended by most manufacturers to test efficiency of these columns. Alternate standards may be used to  determine other characteristic of a GPC column, e.g., exclusion volume.
    QuestionQ159How can one properly wash GPC columns (safely)?
    AnswerA159Wash  the column in the reverse direction, not attached to the detector and at half the recommended flow rate (keep the pressure below the recommended maximum).  First choose a solvent that will dissolve what you believe has contaminated  the column. Most GPC columns are PS-DVB and you need to check the solvent compatibility before using a solvent. Many wash solvents are a higher  viscosity than the typical eluting solvents so a lower flow rate with careful  attention to pressure is needed. Anionic samples can adsorb onto PS-DVB and if these have contaminated  your GPC column a wash solution with a salt is recommended. Check to see what  types of salts are recommended for the column. In some cases the polarity of the material adsorbed may require washing with organic solvents modified with  acid (formic or acetic) or base (triethanolamine) (check the pH range) or  some water may be compatible with an appropriate organic solvent. If more hydrophobic material were retained, elevated temperature along with an  appropriate organic solvent would be recommended. Once again you need to check the maximum temperature range allowed for your column. If you wash carefully the column should not degrade from the solvent switching.
    QuestionQ160How do I calculate conditions for my Prep LC column?
    QuestionQ161How do I perform column conditioning for IP391/07  Diesel analysis?
    AnswerA161The column sequence should be SB-CN first and Zorbax NH2 second. The NH2 column needs a conditioning step before use according the attachment.  The used solvent must be extremely dry to avoid retention time and separation changes.
    QuestionQ162How do you clean C4 column?
    AnswerA162Much as you would any RP-phase column and I've included some general  instructions provided that you are using standard mobile phase conditions to separate small molecules. If you are separating peptides and proteins or if  your sample is dissolved in plasma, then the guidance is different and I recommend that you call 800-227-9770, press option 1 and ask for HPLC column  technical support for more information (within the US, other areas contact  your local Agilent sales office.
    QuestionQ163How do you evaluate for column voids?
    AnswerA163First  check your method and find out if you have operated at a pH higher than is recommended for the column. This is probably the major cause of column voids  because silica can dissolve causing the column void. The sample injection  solvent as well as the mobile phase needs to be considered here. If there is  a column void, you will see a change in peak shape - tailing, broadening, or  split peaks - on every peak in the chromatogram. A void will not usually cause a change in only one peak in the chromatogram. It also does not  typically cause a change in analyte retention. You can also turn the column  around and if there is a column void then the peak shape should be poor in  the reverse direction as well. The only definitive way to check for a column  void is to open the column and this should be done only as a last resort in identifying the problem with the column.
    QuestionQ164I can’t get enough retention of my basic compounds at low pH, what column should I try next?
    AnswerA164The  Eclipse XDB column can be used in the intermediate pH region — from pH 3 - 8 for the longest lifetime. The primary advantage of using the intermediate pH  region is a possible increase in retention for basic compounds. Most basic  compounds have pKa values of 5 or greater, therefore at pH 6 - 8 some of  these compounds may become non-charged and the column will retain them more.  In addition, at pH > 5 the residual silanols on the silica surface will become charged. This can lead to stronger interactions with basic compounds  and increase retention. The Eclipse XDB column is the ideal column to use in  this mid-pH region because the dense-bonding and double end capping will cover the most active silanols on the surface of the column, and any residual  silanols can contribute to increased retention of basic analytes without  causing excessive peak tailing. Figure 1 shows a plot of retention vs pH for  a group of basic compounds. At pH 6 and higher the retention of all of these  compounds increases due to increased interaction with the column, though at  pH 6.5 only Triprolidine is non-charged. If retention has not increased enough, then the next step would be to  try the Extend-C18. All of the basic compounds shown in Figure 1, except  Triprolidine, have pKa values of 9.0 - 9.2. Therefore they must be analyzed at pH 10 or higher before they are non-charged. The Extend-C18 can  effectively be used at this high pH to improve the retention of basic compounds.
    QuestionQ165I typically select 4.6 x 250 mm, 5 µm columns for my analytical work because I have complex samples, but I need to reduce my analysis time and increase my sample throughput. What can I do?
    AnswerA165Rapid  Resolution columns are ideal for your needs. A Rapid Resolution 4.6 x 150 mm, 3.5 µm column will reduce your analysis time by 40% while maintaining your  resolution. Your gains are in reduced analysis time, whether you are doing isocratic or gradient separations, and substantial solvent savings (Figure  5). You may be able to choose even shorter Rapid Resolution column lengths and maintain the desired resolution (Rs) because Rs a N1/2. This means that  decreasing column length, and therefore efficiency, will not decrease Rs by  the same amount. It is likely that resolution will be maintained on even shorter column lengths and choosing 75 mm or even 50 mm column lengths can  reduce analysis time even more.
    QuestionQ166I’m currently using a C18 column and my separation has a couple of peaks that elute early and a couple of peaks that elute late. What can I do to reduce the analysis time and maintain resolution of the early eluting peaks?
    AnswerA166First,  you could try a gradient elution method on the C18 column. But many people do not like to use gradients, so choosing a different bonded-phase may help.  Short chain polar bonded-phases such as the SB-CN and SB-Phenyl are ideal for  separations like this. The increased polarity of these phases reduces retention of the later eluting hydrophobic compounds while often maintaining  the retention of earlier eluting hydrophilic compounds. Figure 2 shows this  clearly. Using the same mobile phase conditions these three compounds are well resolved on the SB-CN in about 5 minutes. The same separation on the  SB-C8 column takes nearly twice as long and provides incomplete resolution.
    QuestionQ167I’m trying to separate some very difficult basic compounds at pH 2.5 using a C18 column and their tailing factors are still too high — around 2.0. Which column should I try next?
    AnswerA167The  Bonus-RP column would be a good column to try. This column has an amide group in the alkyl chain. This amide group reduces interactions between basic  compounds and the residual silanols on the silica surface by acting as an  internal competing base and reducing peak tailing of basic compounds. The Bonus-RP column, while ideal for the mid-pH range where silanol interactions  are more likely, will also improve peak shape at low pH. The Bonus-RP column  uses the same sterically protecting bonding used for StableBond columns. This improves the lifetime of the Bonus-RP column at low pH and makes it a good  choice in situations like this.
    QuestionQ168If one peak in a chromatogram is tailing but the others are not, what is the likely cause?
    AnswerA168Peak  tailing can be caused by a variety of reasons and I would prefer to ask you several questions about your sample before I submit a response. Since most of  the peaks in your chromatogram are well shaped and only one is tailing, I  suspect that the chemistry of the column and sample are such that a secondary interaction is inducing the tailing. Modifying the mobile phase or selecting  another HPLC column can reduce these secondary interactions.
    QuestionQ169I'm having a problem with resolution and selectivity for a phenyl column using different lots, how can I resolve this problem?
    AnswerA169First,  evaluate the methods used on each column. Are their any differences in the column histories or column equilibration procedures? Differences in either of  these may alter the behavior of analytes on a column. Recently someone had a  problem with a change in resolution and selectivity on two phenyl columns, which was resolved by flushing the column once again with 100% methanol. This  may make a good starting point for you. In the case I just described we had a  third column lot to compare it to so that when we flushed the column and retested the sample in its mobile phase we achieved the expected results and  knew that this flush should be added to the equilibration procedures. Our  typical recommendation would be to flush the column with 100% acetonitrile or methanol, which ever is used as the organic modifier in the mobile phase. In  the case I described, only the methanol changed the column, possibly due to  interactions with the phenyl rings in the bonded-phase. You should also make up fresh mobile phase  and test it in case the problem occurred with the mobile phase and make sure the instrument is operating as expected. These steps will eliminate some of  the potential sources of column-to-column variations. The next step is to review your method  ruggedness. Are any of your analytes sensitive to pH or ionic strength? If slight changes in pH or ionic strength affect retention then you may need to  modify your method and select conditions where changes in these parameters do  not affect resolution and selectivity as much. Acidic and basic analytes can be very sensitive to pH and ionic strength changes around the pKa of the  analyte. Finally ask the column  manufacturer for assistance. They may be able to supply additional columns  from older lots that have worked or from newer lots while the method is evaluated. The manufacturer may also be able to make some suggestions based on  your method parameters.
    QuestionQ170I'm working with environmental samples that may contain sulfur. I suspect that a few samples insufficiently cleaned up. Column performance has declined significantly. Is there any way to restore performance?
    AnswerA170I  assume you are using a reversed-phase column. Please review the recommended HPLC column cleaning procedure . I do suggest that if column performance  declined quickly that you consider using a guard column and possibly consider  including a preliminary clean-up step before injection.
    QuestionQ171Is a Rapid Resolution 3.5 µm column more likely to fail than 5 µm column?
    AnswerA171No. The  Rapid Resolution columns are as rugged as the 5 µm, 250 mm columns. There are two types of accelerated column failure attributed to using smaller  particles. First, smaller particle columns are thought to plug faster. This  is not true when a standard 2 µm frit is used at the top of the column. Because of careful particle size control and the use of 3.5 µm particles,  ZORBAX Rapid Resolution columns will not contain any particles as small as 2  µm. This means a standard frit can be used on the column and the Rapid Resolution columns will be no more prone to plug than a 5 µm particle size  column. Second, columns with smaller  particles are thought to have shorter lifetimes because the column beds  compress, leaving voids that cause peak broadening and tailing. It is true that 3.5 µm particle size columns will operate at slightly higher pressures  than 5 µm columns, but ZORBAX particles can easily withstand these increases  in pressure. ZORBAX particles are packed at 8000 psi and can easily withstand pressures up to 5000 psi in routine use. A Rapid Resolution 4.6 x 150, 3.5 µm  column will typically be operated below 3000 psi, so the column bed will not  compress when using ZORBAX Rapid Resolution columns. So both the rugged ZORBAX particles and the standard 2 µm column frit assure you long column  lifetime when using Rapid Resolution columns.
    QuestionQ172Is there a way to separate Copper galacturonate from Copper gluconate?.
    AnswerA172I suggest trying ZORBAX SAX 70Å 5um, 4.6 x 150mm 820888-901, with water and acetonitrile mobile phase, say 50% to start. Hopefully the two -OH rich compounds will be retained on the quaternary amines of the SAX column, adjust water strength to elute.  UV detection (230 nm) should work since they both have a carbonyl.
    QuestionQ173Is there any kind of "generic" column test to track the performance of a column?
    AnswerA173The best way to evaluate a  columns performance is to use the QC test that should be shipped with each  HPLC column provided to you. By comparing the efficiency, retention and peak shape of the peaks in the sample and very importantly the pressure under  these experimental conditions, you will be able to tell if your column has changed over time. These tests can also tell you how your column has changed,  as these are the same tools we use to diagnose a column problem. Significant  changes in retention, can suggest loss in bonded phase and significant  changes in peak width/efficiency and pressure can suggest column  contamination. Dramatic losses in peak width and efficiency suggest a column void. Most manufacturers use similar  solutes and mobile phase test conditions to QC their columns. However, different bonded phase require modification of the amount of organic modifier  to achieve reasonable retention. What's important is that that you QC-test a column on your system  before you use it for a particular project. Then you know how that column  performs on your system, before you start injecting samples and before you start having problems. If problems develop, use this QC-test to verify that  the HPLC system and the column are performing well. Before you retire a column from a project, clean and QC-test the column. If for any reason, you  start a project with a used column, at a minimum, QC-test the column before  injecting samples.
    QuestionQ174LC & LC/MS Columns - USP Designations
    QuestionQ175LC Column User Guides
    QuestionQ176My work requires very high sample throughput. How fast can I do a gradient separation?
    AnswerA176            More  and more people, especially those who analyze combinatorial chemistry samples, need to analyze a lot of unknown samples quickly. The best way to do  this is on short, Rapid Resolution columns with rapid gradient times. The  best gradient time is the one that resolves all of your analytes in the least amount of time. On very short columns — 30 and 50 mm lengths — a good  starting point would be a 2 - 5 minute gradient. From there optimize your separation for organic range and gradient time. On these short columns you  can easily increase the flow rate to further decrease analysis time to 30 seconds without exceeding the pressure limits of the columns. Column  re-equilibration times are typically as short as the analysis times — 3 - 5  minutes for the 50 mm columns.
    QuestionQ177Should I just select the Bonus-RP column for all my method development with basic compounds?
    AnswerA177Basic  compounds are best analyzed following the method development scheme outlined earlier in this brochure. Select an SB-C8 or SB-C18 column for initial  development and use a buffered low pH mobile phase. Many times this approach  provides a good separation and the StableBond columns will have exceptional lifetime at low pH even at high temperatures.
    QuestionQ178Some manufacturers’ indicate (newer) columns can be reversed to remove blockage from the front of the column. Is this generally recommended or does it depend on the column?
    AnswerA178HPLC  columns are more efficient and packed better than years ago, therefore this is generally recommended for most reversed-phase and normal phase silica  based columns. This procedure is designed to remove particles from the column  frit when high pressure occurs at the column inlet, but it will not work all the time. Because it does not require opening the column it is worth trying.  Make sure when you do this that you disconnect the column from the detector  and make sure the particles that plugged the column are not coming from the HPLC system or you may just plug the frit at the back end of the column and  this may not be replaceable. Columns can also be turned in the reverse  direction for washing/cleaning with stronger solvents to remove adsorbed material.  This has the benefit of not exposing the rest of the column to the contaminants. When this is done the column should also not be attached to the  detector.
    QuestionQ179There are a lot of different column configurations (dimensions) available, but I don’t see the one I’m looking for. Can I get a column made in the configuration I want?
    AnswerA179Most  likely. Agilent is continually adding to its HPLC column offerings, so check with your Agilent column distributor or in the US call Agilent Customer  Assist at 800-227-9700 and ask for HPLC column support to find out if the  column configuration you need is currently available. For locations outside  the U.S., your authorized Agilent column distributor, listed on the Agilent  website, can also help you find out the cost and delivery time. If the column is not available, a column can be packed in the configuration of your choice  with available bonded-phases. Select an internal diameter and specify a column length, bonded-phase, and particle size using product number  899999-999. A special products quote (SPQ) will then be issued to track your  order.
    QuestionQ180USP designated LC Columns - 1050 LC
    QuestionQ181Very short narrow-bore columns seem ideal for LC/MS. What bonded phase should I use?
    AnswerA181LC/MS  requires volatile mobile phases and the most suitable buffers are acetate and format. The buffer range for acetate is from pH 3.8 - 5.8 so the best  bonded-phases to start with would be the Eclipse XDB C18 and C8. Formate is  also widely used and has a buffer range from pH 2.8 - 4.8. When using this buffer you can select StableBond columns then Eclipse XDB columns and follow  the same method development scheme as discussed in the method development  section. For high pH, using ammonium hydroxide at pH 10.5, select Extend-C18.
    QuestionQ182What are the steps to troubleshoot leak errors?
    QuestionQ183What column do you recommend to analyze raw materials?
    AnswerA183Column choice, and appropriate mobile phase, depends on many characteristics of the sample such as polarity, pKa of ionizable functional groups, solubility vs. pH, and molecular weight.
    QuestionQ184What do you recommend doing when a impurity peak starts to co-elute and actually starts to make itself present in your main peak as a hump to the peak?
    AnswerA184How much of a change in resolution are you seeing? Has resolution decreased over time or has the separation been  disappointing right out of the box? Do you have any information telling you what factors may cause these peaks to converge? Are they sensitive to small  changes in temperature, pH or organic composition? Is one compound much larger than the other? These factors and more can be causing the two peaks to  merge.  More information would be required to specifically answer this question.
    QuestionQ185What do you think about neutralizing extra-column volume by packing short columns with wide-bores (7mm)?
    AnswerA185As long  as you are willing to accept operating at a higher flow rate. If you operate  at 1.0 mL/min on a 4.6 mm i.d. column, then operating at 2.3 mL/min would be  the equivalent linear velocity when using a 7.0 mm i.d. column. Solvent waste  may be an issue.
    QuestionQ186What does the filter do that the guard-column does not?
    AnswerA186Nothing  really - both a filter and a guard can capture small particulates that are either coming from your sample, mobile phase or are from wear-and-tear of  instrument seals and gaskets. A guard, on the other hand, traps sample material that is strongly retained on your column, material that would not  elute from the column under the experimental conditions defined by the method. These strongly retained materials can build over time at the head of  the column and generally lead to high pressure and/or poorly shaped peaks. In  some cases, these retained materials cannot be removed even after extensive washings with strong solvent.
    QuestionQ187What does the Flexible Stainless Steel Capillary Tubing Color-Coding Indicate? - 1090 Series LC
    QuestionQ188What is meant by peak plate?
    AnswerA188Plates"  allow you to compare the efficiency of different columns and its measure is  determined by the width of a peak in a chromatogram relative to its retention. In general, for the same retention , the more narrow a peak, the  more efficient the column and the more efficient the column has more "plates". HPLC instruments often determine column plates or  efficiency by measuring the peak width , typically at half-height, using the following equation:N = efficiency = plates = 5.54(tR/w1/2)2 ,w1/2 = peak  width at half-height in min.,tR = retention time in min. The efficiency of a column is reported by the manufacturer of your column and is generally  provided in a column report. For a more detailed discussion on how plates and  column efficiency relate to resolution and your analyses refer to the text Practical HPLC Method Development written by Lloyd R. Snyder, Joseph J.  Kirkland and Joseph L. Glajch, Wiley-Interscience , Second Edition, 1997.
    QuestionQ189What is the purpose of the H3PO4 wash of the column?
    AnswerA189A  phosphoric acid wash has been shown to be effective at reducing tailing  caused by the sample complexing with metals in the HPLC system. Typically a  1% phosphoric acid wash of the system and column is suggested to eliminate  this tailing and it works. It is perfectly reasonable to use these  recommended wash conditions with Agilent ZORBAX StableBond reversed-phase  HPLC products. The StableBond HPLC column is particularly stable at low pH -  the SB-C18 column is stable at a pH of 0.8 and 90°C. How can you tell if your peak tailing is caused by metal complexation? Look to see if a lone pair of  electrons on either a N or O atom can chelate with the metal to form a 5 or  6-membered ring. Metal complexation is a commonly overlooked cause of peak tailing and metals are presents in every HPLC system.
    QuestionQ190What might cause a rhythmic, wavy baseline?
    AnswerA190This is  rarely a column problem. The most common causes of this problem are related  to the pumping system. a) If you have an isocratic pump, your pump seals may  be worn. Typically your pump will have two pistons and seals. One may be more worn than the other causing flow and pressure variations in a very rhythmic  pattern, which will also be seen by the detector. You can confirm a pump seal  problem by varying the flow rate. The frequency (in time) of the baseline fluctuations will increase/decrease proportionally to an increase/decrease in  the flow rate if the pump seals are worn. The solution is to replace the pump  seals. b) If you have a multiple pump  system (binary, ternary, or quaternary), the problem may also be pump seals  but could also be a function of insufficient mixing or of a malfunctioning proportioning valve. The former can be solved by adding a mixing column (ask  your manufacturer for a recommendation) and the latter by a service call. Another possibility is an aging lamp  although these signal fluctuations are not as perfectly periodic as a pump  problem. An aging lamp can be distinguished from a pump problem with the flow  rate experiment described above. If the frequency of signal fluctuations (in time) don't change when the flow rate is varied, the problem may be the lamp.
    QuestionQ191What solvents do you recommend to clean the columns?
    AnswerA191I  generally recommend using the organic solvent acetonitrile to clean reversed-phase, C8 or C18, silica-based HPLC columns. THF is a strong  reversed-phase organic solvent and that may be difficult to remove from hydrophobic bonded-phases, causing chromatographic variability. For most  situations, acetonitrile is a strong enough solvent to remove sample and mobile phase components that have accumulated on your column during routine  isocratic use. Before cleaning the column  with organic solvent however, be sure that you have removed any buffer salts  that may be in your mobile phase and column to avoid precipitation of these salts in the column. To do that, prepare your mobile phase without buffer  salts and flush your column with 15-20 column volumes of this mixture. That  is, if your mobile phase is fifty-percent acetonitrile and fifty-percent 50  mM phosphate buffer, then the appropriate first step would be to remove the  buffer salts with 50/50 mixture of acetonitrile and water. Then I would suggest flushing the column with pure acetonitrile thoroughly for 30-40  column volumes. If you believe there may particulates at the top of the column, e.g., pressure may be higher than normal, you should consider  disconnecting the column from the detector and reversing the direction of  flow before the cleaning step. Do no reconnect the column to the detector, but allow the cleaning solvent, in this case, acetonitrile, to collect in a  beaker. Since acetonitrile is commonly recommended for long-term column storage, the column can be easily stored after cleaning using the procedure  described above. When ready to re-use this stored solvent, remember to flush  the column with your mobile phase composition without buffer salts before introducing the buffered mobile phase, again to reduce the possibility of  salt precipitation.
    QuestionQ192What temperature should I use for my separation?
    AnswerA192Temperature  control for separations is important for long-term retention reproducibility,  one factor of method ruggedness. Controlling temperature at 35 - 40°C is  normally sufficient for good method reproducibility and ruggedness. In  addition, the use of elevated temperature can have other benefits. First, it reduces the system operating pressure by reducing the viscosity of the mobile  phase. Second, it will reduce analysis time, which can substantially increase  productivity. Third, temperature may change the selectivity of a separation. Not all compounds have the same response to temperature so the selectivity of  a separation can change dramatically when temperature is increased or  decreased. StableBond columns have high temperature limits — SB-C18 can be taken up to 90°C, at low pH, and SB-C8 , SB-Phenyl , SB-CN and SB-C3 can be  taken up to 80°C, making it possible to optimize your separation without changing columns, particularly if you are analyzing ionizable compounds.
    QuestionQ193What types of column are dissolved above pH 7?
    AnswerA193Many  commercially available silica-based HPLC packings dissolve at pH 7, for the simple reason that silica is soluble at pH 7. Therefore, Agilent has  developed technology to significantly reduce silica dissolution and extend  the usable pH range of silica-based columns. The ZORBAX Extend-C18 can be effectively used above pH 8 and even up to pH 11.5. Bidentate-bonding is key  to this enhanced stability while offering the high efficiency that only silica can provide.
    QuestionQ194What's the best procedure for cleaning out ion pair reagent materials from a column?
    AnswerA194Some  detergents are used as ion-pair (IP) reagents, e.g. SDS with a carbon chain length of twelve. However, most commonly used ion-pair reagents have shorter  carbon chains, e.g. hexane sulfonate has carbon chain length of six. IP reagents with longer carbon chains are more difficult to remove from RP-HPLC  columns. Studies have shown that ion-pair reagents and some detergents are  best removed with long washes with a 50/50: v/v, methanol/water mobile phase system. If you can regain the retention, selectivity and efficiency  (resolution) of a known separation (e.g., QC sample) after washing, then you  might have successfully removed the ion-pair reagent. I would not recommend using this column for developing a new method as exposure to ion-pair  reagents may change the retention characteristics of a column permanently. If scouting runs for a new method are conducted on a column exposed to ion-pair  reagents, a new column should be purchased as soon as possible to verify that  the selectivity is not different. In my opinion, columns exposed to IP reagents should be dedicated to the ion-pair method.
    QuestionQ195When do you see peak fronting?
    AnswerA195Peak  fronting can occur under a variety of conditions. The most well known is peak fronting that occurs due to column overload. In this case you will typically  see the peak retention time shift slightly shorter. This is also the simplest  to evaluate, because you can just inject less sample and evaluate the peak shape. But there are at least four  other causes of peak fronting. These are column channeling, ionic  interactions between the analytes and the silica, poor solubility of the  analyte in the mobile phase, and wettability problems between the mobile phase and bonded-phase. A problem with column channeling should result in  peak fronting on all peaks or at least the largest peak in the chromatogram if the others are very small. If this occurs you need to replace the column.  To evaluate this problem try a new column. Increasing the buffer ionic strength or changing the pH of the mobile  phase can often improve ionic interactions, which cause fronting. Increasing  the ionic strength can reduce interactions between the silica and ionic  analytes and changing the pH can have the same effect. Solubility needs to be assessed by trying  to improve the solubility of the analyte and evaluating the resulting  chromatogram. For instance, you can increase the time you sonicate your sample and re-inject or dissolve it in a solvent where the sample has good  solubility and then dilute and inject in the mobile phase. Also any sample you suspect has a solubility problem should be filtered. You can also mix  your sample and mobile phase off-line to see if it is visibly soluble in the  mobile phase. Wettability refers to  the ability of the mobile phase to fully penetrate the bonded-phase so that analytes interact with all of the bonded-phase. In cases where there is a  highly aqueous mobile phase with a C18 column complete wettability may not be achieved. The bonded-phase can fold over on itself. The results may be loss  of retention and distortions in peak shape. If you can, increase the amount of organic in the mobile phase and re-evaluate peak shape. If not you may  need to consider selecting a column designed for use in very high aqueous mobile phases. These are the typical  causes of peak fronting and some solutions
    QuestionQ196When should I select Phenyl bonded-phases?
    AnswerA196Both  SB-Phenyl and Eclipse XDB-Phenyl bonded phases provide unique selectivity and are often a good choice for changing the selectivity for two closely eluting  analytes. Phenyl bonded phases are less retentive than C8 bonded-phases so  they offer a second option for reducing retention of late eluting hydrophobic compounds and minimizing analysis time
    QuestionQ197Where can I find the LC Column User Guides?
    QuestionQ198Why are there ghost peak In my chromatogram?

    LC Pumps

    QuestionQ199At what interval should the pump seals be replace?
    QuestionQ200At what interval should the pump seals be replaced?
    QuestionQ201What are the steps to replace the pump seals?
    QuestionQ202What is the break / wear - in procedure for piston seals?
    QuestionQ203What lubricant should be used on the base of Sapphire Plungers?
    QuestionQ204What types of injector rotor seals are available?

    Sample Preparation

    QuestionQ205Are any additional accessories or parts included with the purchase of a PPM-48 (p/n 5191-4101)?
    AnswerA205Yes. The PPM-48 is shipped with: • Waste rack with three waste bins p/n 5191-4112 • Installation kit p/n 5191-4114 • User Manual publication number 5991-8133EN The manifold comes with a sealing gasket already installed.
    QuestionQ206Are any additional accessories or parts included with the purchase of a PPM-96 (p/n 5191-4116)?
    AnswerA206Yes. The PPM-96 is shipped with: • Single well waste plate p/n 5191-4121 • Holder for plates p/n 5191-4120 • Installation kit p/n 5191-4114 • User Manual publication number 5991-8133EN The manifold comes with a sealing gasket already installed
    QuestionQ207Are there any consumables or parts that I need to regularly order or replace?
    AnswerA207The only part that needs to be regularly replaced (both units) is the sealing gasket (PPM-48: 5191-4110; PPM-96: 5191-4117). Please note that each processor has its own unique sealing gasket (different p/n- because they are different shapes). Agilent recommends ordering these parts as needed due to adhesive expiration dates. The PPM-48 also uses disposable waste bins (p/n 5191-4113) to collect waste during various sample processing steps. They can be reused (customer's best judgment should be used to determine when they need replacement- depends on solvent(s) used, hazard of the sample/solvent, wear and tear, etc.). The single well waste plate for the PPM-96 (p/n 5191-4121), like the PPM-48 waste bins, is also a consumable, and while it can be reused, it should be replaced as necessary.
    QuestionQ208Does the processor require any maintenance and if so, how often should it be performed?
    AnswerA208The sealing gasket should be wiped periodically with methanol and a lint free cloth. For simplicity, this can be done after every extraction procedure is completed. The sealing gasket should also be replaced 1-2x per year depending on wear, solvent usage, and overall condition. Instructions for replacement are included with each new sealing gasket and are also found in the user manual (5991-8133EN). If the two sets of instructions differ, use the instructions that are included in the box with the sealing gasket. Wiping of the whole processor can be performed as needed with compatible solvents/water.
    QuestionQ209Does the rotameter help control flow for both Low and High Flow modes?
    AnswerA209No, the rotameter is only used for fine control for the Low Flow mode. When using Low Flow, the gas will run through low flow regulator and through the rotameter before entering the manifold to allow for more fine control at low pressure. When using High Flow, the gas will run directly from gas supply through the high flow regulator to the manifold.
    QuestionQ210For the PPM-48, which switches correspond to which rows?
    AnswerA210As you are looking at the top of the manifold, the row furthest in the back (farthest from the front of the processor) will shut off the entire row A. The second switch from the back will shut off row B, and so forth. Therefore, the closest switch as you are looking at the front of the PPM-48 is for row D. The cartridge rack is labeled with Rows A-D. Row A is in the back, moving up to row D in the front.
    QuestionQ211For the PPM-48, which switches correspond to which rows?
    QuestionQ212For the PPM-48, why does my 1 mL cartridge rack have a black bar in between rows B and C when the other cartridge racks don’t have this bar? It is blocking my view of some of the cartridges. The bar has screws to hold it in place, so can I remove it?
    AnswerA212NO, you cannot remove this black bar. The bar is intended to provide additional stability to the 1 mL cartridge rack during compression. It is necessary to ensure proper pressure distribution between cartridges 1-12. The black bar sits between rows B and C making it more difficult to view cartridges that are in rows A and B. However, the bottom tips of the cartridges are still visible, and can be used to monitor flow of these rows if desired.
    QuestionQ213How can I disconnect the processor from the nitrogen source?
    AnswerA213To remove the tubing from the back of the manifold (“gas inlet”), compress the outer ring of the push to connect fitting while simultaneously pulling out the tubing.
    QuestionQ214How do I set the pressure for the processor?
    AnswerA214The processor has locking regulator knobs, one for Low Flow and another for High Flow. Pull out ****. Turn clockwise to increase pressure. Turn counter-clockwise to decrease pressure. When desired pressure is achieved, push **** in to "lock" pressure. It is easier to monitor/set the pressure when the flow rate selector is set to Low Flow or High Flow and the gas source is turned on.
    QuestionQ215How do I set the pressure for the processor?
    QuestionQ216How do I use Captiva Syringe Filters?
    QuestionQ217How frequently should I replace the manifold gasket on the processor?
    AnswerA217  We recommended replacing them at least once a year for PM purposes.  Under heavy use you might need to replace them once to 3 times per year depending on usage.  We recommend daily inspections of the column seal for any signs of wear and recommend replacing if there are any visual signs of rip or tears as well as the column seal peeling off of the manifold.
    QuestionQ218How frequently should I replace the manifold gasket on the processor?
    QuestionQ219How often should I replace my BHT-2 or BHT-4 gas filter?
    AnswerA219BHT-2 and BHT-4 traps are designed to filter 13 standard cylinders of gas. If you are unsure of the gas input quantity, a replacement interval of 1 year is recommended. Depending on usage, the filter can last up to 2 years.
    QuestionQ220I can’t remove the back tubing on the positive pressure regulator, even when I follow the appropriate instructions.
    AnswerA220Sometimes the outer ring of the push to connect fittings can be dislodged. This may (but not always) be obvious visually, and will look like the outer ring is sticking out way more than the outer ring on a different push to connect fitting. One of the main causes of this dislodgment is trying to remove the tubing without pushing the outer ring in. Try re-seating the outer ring into the push to connect fitting with a pair of plyers by simply pushing the outer ring into the fitting (the tubing should be still connected- do not pull on the tubing while you are doing this). Once the push to connect fitting has been reseated, you should be able to push on the outer ring and simultaneously pull out the tubing.
    QuestionQ221I see a pressure drop for High Flow pressure when I turn the flow selector from Off to High Flow. Is this normal?
    AnswerA221Yes, it can be. When the processor is in Off mode, there is no gas flowing through the system which can cause a slight back pressure to occur. When the flow selector is set to High Flow the gauge will immediately display the pressure that is currently being applied to the processor. For the PPM-48, with each row that is turned on via the row switches, there may be a slight decrease in the observed pressure in the high flow gauge. For example, if the high flow pressure is set to 80 psi with no rows on, the pressure will read 80 psi. As each row is turned on you may experience a 1-3 psi drop in pressure (if you are looking at the gauge). This is normal. However, if you are experiencing a much higher drop in pressure as row switches are turned on, it is most likely due to your input gas supply not meeting the minimum required pressure for the processor.
    QuestionQ222I see a weird flow pattern when I am using 1 mL cartridges with my PPM-48. The end cartridges (columns 1-2 and 11-12) flow faster than the middle cartridges (3-10).
    AnswerA222Ensure that the 1 mL cartridge rack has the black stability bar installed and that it has not been removed. Without the stability bar, the cartridge rack may not compress correctly which can lead to inconsistent or variable pressure differences across the row.
    QuestionQ223I’m struggling to remove the white paper backing of a new replacement sealing gasket.
    AnswerA223If the white paper backing of the replacement sealing gasket is difficult to remove- STOP immediately. One reason for the trouble may be because the adhesive is actually sticking to the paper backing and is being removed from the seal as you pull the backing off. The white backing when removed should be very smooth to the touch, and not sticky at all. You can use tweezers to help start to peel the backing off. Try a corner first, but if you are still having trouble, sometimes starting from the middle of the sealing gasket may work better.
    QuestionQ224My sealing gasket won’t stick to the manifold.
    AnswerA224If the sealing gasket is old and currently installed: Replace the seal. If the replacement sealing gasket is not sticking initially: Ensure that all old adhesive has been removed from the manifold prior to attempting to attach a new sealing gasket. Old adhesive can be removed with acetone and/or isopropanol. A lint-free cloth should be used to prevent contamination to any of the manifold air holes. Avoid getting old adhesive into the manifold holes. If you notice adhesive in the holes, use small tweezers or similar item to remove all adhesive. Ensure that the white backing has been removed from the sealing gasket. The backing should remove clean (i.e. no adhesive residue should be on the backing). The back of the sealing gasket should feel sticky. Check to ensure that the adhesive remains on the sealing gasket as sometimes, the adhesive can be removed with the backing, rendering the sealing gasket not sticky! Press firmly to ensure the sealing gasket is attached. Follow specific instructions provided with the sealing gasket or in the manual to ensure proper installation.
    QuestionQ225What are the recommended pressures for Low Flow and High Flow?
    AnswerA225Low Flow starting pressure recommendation is 3-4 psi, with the rotameter almost, but not fully, closed. If using High Flow for drying steps, any pressure between 50-80 psi is acceptable. Pressures can be set lower for High Flow for eluting more viscous samples. There is no pressure recommendation for this scenario as it will be sample dependent.
    QuestionQ226What are the recommended pressures for Low Flow and High Flow?
    QuestionQ227What happens if I accidently lower or raise the manifold with the gas flow on (set to Low or High flow)?
    AnswerA227It is recommended to set the flow rate selector to Off when you are going to raise or lower the manifold. Movement of the manifold requires gas (it is all pneumatic). If you have the flow rate selector turned to Low Flow or High Flow then gas will be flowing through the manifold already. This is gas that is now not available to raise or lower the manifold. Therefore, to ensure enough gas is available to lower or raise the manifold, the flow rate selector should be set to Off during every compression/decompression step.
    QuestionQ228What if I am using a harsh solvent in my sample preparation procedure?
    AnswerA228First, ensure that you have your processor installed in a location with proper ventilation, such as a fume hood, as dictated by the hazards of the solvent(s) being used. Also, ensure that appropriate personal protective equipment (PPE) such as gloves, googles, lab coat etc. are used according to the hazards. Regarding the effect of the harsh solvent on the processor, ensure that if any of the solvent spills on the processor or any of its components/accessories, it is wiped up immediately. Dispose of the waste and clean-up materials as dictated by the hazard and/or your laboratory protocols. It is especially important to wipe up any solvent that is on the cartridge rack, cartridges, or 96-well plate prior to compression. Prolonged exposure to solvent can damage the sealing gasket, so all efforts should be made to prevent direct contact with any solvents. Unnecessary, prolonged contact of the manifold (sealing gasket) and cartridge rack or 96-well plate should be avoided. Compression should occur only as dictated by the sample preparation method.
    QuestionQ229What if I don’t have access to compressed nitrogen?
    AnswerA229The processor can operate using high purity filtered instrument air.
    QuestionQ230What if I don’t have access to compressed nitrogen?
    QuestionQ231What is the charge capacity for SampliQ SCX 5982-3267?
    AnswerA231Our Polymeric SCX averages ~1,000 umol/g based on both elemental analysis and breakthrough method
    QuestionQ232What is the rotameter and how do I use it?
    AnswerA232The rotameter is a device that measures the flow rate of a fluid or gas (in the case of the PPM it is measuring the GAS flow rate). The units for the rotameter are SCFH- standard cubic feet per hour- and will measure from 0-2.5 SCFH. The rotameter is only used with the Low Flow setting. Turning the rotameter **** counter clockwise will open the valve. Turning the **** clockwise will close/shut off the rotameter.DO NOT SHUT OFF THE ROTAMETER. Anytime the rotameter needs to be turned down/closed more, it is important to turn clockwise while ensuring you never fully close the valve. As soon as you feel any resistance, stop. It is a good idea to perform a slight counter turn to ensure it is not closed. Permanent damage can occur to the rotameter if the **** is closed regardless of whether the gas flow is on. Again, the rotameter should never be shut off regardless of gas flow being on or off. It is generally good practice to monitor the flows for the fastest flowing cartridges/wells and adjust pressure accordingly to ensure they are at the right level. As those cartridges/wells finish eluting, the rotameter can be opened more to allow more pressure to reach the slower flowing cartridges/wells.
    QuestionQ233What other parts or accessories do I need to order with my PPM-48?
    AnswerA233Regardless of sample preparation technique, a cartridge rack(s) will need to be purchased (3 options). Cartridge racks: 1 mL cartridge rack p/n 5191-4102 3 mL cartridge rack p/n 5191-4103 6 mL cartridge rack p/n 5191-4104 A collection rack(s) (to hold test tubes or autosampler vials) will also be necessary. Collection racks: 10 × 75 mm tubes p/n 5191-4105 12 × 75 mm tubes p/n 5191-4106 13 × 100 mm tubes p/n 5191-4107 16 × 100 mm tubes p/n 5191-4108 12 × 32 mm autosampler vials p/n 5191-4109 If you are doing SPE, then you most likely have all or some of the following steps PRIOR to elution in which you will not want to collect the eluting liquid: conditioning, equilibration, loading, washing. Unless you wish to collect the liquid from these steps, then a waste rack with waste bin will be very useful. The waste rack and a 3/pk of bins are included with the initial purchase of a PPM-48; however, additional waste bins (3/pk: p/n 5191-4113) may be purchased. It is recommended that you use a gas filter to filter your gas supply. A BHT-4 (1/4 fittings) or BHT-2 (1/8 inch fittings) are available from Agilent. Sealing gasket is a consumable that will need to be replaced (1-2x per year), however Agilent doesn't recommend ordering this at the same time as the processor order due to the expiration of the sealing gasket adhesive.
    QuestionQ234What other parts or accessories do I need to order with my PPM-96?
    AnswerA234Most of the accessories/parts that you will need with the PPM-96 will just be the sample preparation 96-well plate and 96-well collection plate you require for your method. The single well waste plate that is provided with the initial processor order can be reused, but additional can also be purchased as necessary (p/n 5191-4121). If you are planning on using the PPM-96 for tables 1 mL cartridges, a 1mL tables cartridge holder is required (p/n 5191-4119). The sealing gasket is a consumable that will need to be replaced (1-2x per year), however Agilent doesn't recommend ordering this at the same time as the processor order due to the expiration of the sealing gasket adhesive. It is also recommended that you only order as needed, and do not keep lot of spares on hand due to the expiration of the sealing gasket adhesive.
    QuestionQ235What size frits are used in the SampliQ products?
    AnswerA235The pore size of the frits is 20um.  More SampliQ-specific FAQs and answers can be found in the attached document.
    QuestionQ236When I first turn on the flow (Off to Low Flow) I get a large burst of pressure which makes my samples elute at an undesirable rate for the first few seconds. How can I prevent this?
    AnswerA236This "burst" is usually due to backpressure build up from a period of processor inactivity. A slight build-up is normal. To avoid this, you can "prime" the processor. If using Low Flow mode, simply turn the flow selector from Off to Low Flow prior to compression of the manifold for 2-3 seconds or until pressure stabilizes and returns to original setting. Ensure that the flow selector is returned to Off prior to compression. If using High Flow mode, the same procedure can be followed with the flow selector set to High Flow. However, usually this difference in High Flow is nominal since the pressure is already so high. AKA- the difference between 3 and 5 psi (Low Flow) can be substantial for your samples, when the difference between 80 and 83 psi (High Flow) generally won't significantly affect the flow rates of the cartridges.
    QuestionQ237When I turn on my gas supply source, the processor pressure gauges don’t register any pressure.
    AnswerA237Disconnect the gas supply tubing from the processor. Turn on the gas supply source and ensure there is flow coming from the installed gas supply tubing. Turn off the gas supply. Insert the tubing by pushing it into right-hand port ("Gas Inlet") of the processor (when looking at the back of the unit). When the tubing is installed properly, you should not be able to pull it out of the port. Then turn on the nitrogen source.
    QuestionQ238Where can I find the QuEChERS SOP (Standard Operating Procedures)?
    AnswerA238We have a recommended SOP that can be followed using the AOAC 2007.01 and the EN Method 15662 kits.
    QuestionQ239Why can’t I compress/lower the manifold?
    AnswerA239Ensure the nitrogen source is turned on, and the flow rate selector is set to Off. Ensure the processor is receiving adequate gas (60-100 psi) by checking the pressure gauges on the unit. If you are still unsure of the pressure or if the processor is receiving gas, use a pressure gauge/regulator with your gas supply to monitor. Both compression switches must be pressed and held simultaneously to lower or raise the manifold. If you let go of the switches too early, the manifold will raise back up. This in an intentional safety feature. The manifold will stop when it reaches the cartridge or plate stack. Make sure you hold down the switches until this contact has been made. It doesn't hurt the processor to hold the switches for an extra second or two after compression to ensure the manifold is compressed.
    QuestionQ240With what gas supply pressure(s) is the processor compatible?
    AnswerA240The processor can operate with input pressures between 60 psi (minimum) and 100 psi (maximum). Optimum source pressure is 80 psi. If you are unsure of the pressure of your in-house gas, it is highly recommended that a supply gas pressure gauge and/or regulator is installed.

    Syringes and Sample Introduction

    QuestionQ241Do econofilter syringe filters come with a certificate?
    AnswerA241No.  Certificates are not available for econoline vials.
    QuestionQ242How do I choose the right syringe filter for my application?
    QuestionQ243How do I find needle gauge dimensions of a manual syringe?
    QuestionQ244Syringe selection guide
    QuestionQ245What are the steps to change the sample needle?
    QuestionQ246What does the diameter of the filter refer to?
    AnswerA246The diameter of the filter refers to the active membrane diameter, not the filter body.
    QuestionQ247What ships with the Color Coded Manual Syringes?:
    AnswerA247The Manual Syringes ship with an insert that describe how to use the packaging as a syringe holder and general care and use instructions. It also provides instructions for getting the Certificate of Conformance.
    QuestionQ248What syringe offerings does Agilent have?
    QuestionQ249What types of gas chromatography syringes are available?
    QuestionQ250Will the syringe filters work with any manufacturer's syringe?
    AnswerA250The syringe filter has a standard luer connection that should fit any syringe using a standard luer connection.

    Tools, Fittings, Capillaries, Tubing, and Supplies

    QuestionQ251Can an oil free Rough pump be used With a Diffusion pump MS?
    QuestionQ252How are the Markes Difflock caps (MKI-MTD-1204) packaged and what color are they?
    AnswerA252The caps are supplied in packages of 10. They have an inert coating which gives them a unique color/appearance.
    QuestionQ253The UI gold seal has spots – is it used, or rusty?
    QuestionQ254UltiMetal Plus Flexible Metal Ferrule
    QuestionQ255What is the Gold-seal with the cross used for?
    QuestionQ256What is the interval for Rough pump oil replacement?
    QuestionQ257What tool should I use for cutting fused silica columns?
    QuestionQ258What traps are available for the Purge and Trap device?
    AnswerA258Information can be found in the consumables catalog under Teledyne Tekmar Purge and Trap supplies
    QuestionQ259What tubes and accessories are available for the Markes Thermal Desorption system?
    AnswerA259Information can be found in the consumables catalog under Markes Thermal Desorption
    QuestionQ260Where can I find information about Ultimate Unions?

    Vials and Closures

    QuestionQ261Can I use septa on the HPLC vials and test tubes when using…
    QuestionQ262How much can a sample vial be filled?
    QuestionQ263What are 'Certified’ consumables?
    AnswerA263Agilent Certified consumables come with a certificate of analysis, so you can be sure that they will perform even in the most demanding environments.