Forum - Recent Threads

GC transfer line high temperature alarm

Hanadyz — Sat, 17 Apr 2021 19:55:02 GMT

Hello there.

I encountered a problem in my GC HS 7964E twice. The instrument was on and ready for injection, but the transfer line was hot than usual, even more than the set temp.

The actual temperature was reading ''--------'' (blank) and an error message was displayed; "High temperature alarm". It was extremely hot to the touch, and I disconnected it from the instrument and waited till it was cool, then I reconnected it.

After that, I was trying to inject my samples, no peaks appeared at all, but peaks who are supposed to be of large areas appeared but with rather smaller areas.

For example, DMSO whose area is supposed to be ''20000'' was found to be only ''300''!

All other methods that I have in my lab were tried, but all of them were of the same results.

My opinion is that there is a doubt that when the transfer line got too hot, some part melted or broken and it was plugged due to that extreme high temperature.

Please advise. Thank you for your time.

7697A Vials leaking error using Empower 3

Seb99 — Fri, 16 Apr 2021 19:00:22 GMT

I am having an issue regarding the pressurization of my vials. I am using 10 ml vial and cap from Agilent. Leak rate always higher than my limit. Seems to be a known driver error when reading in Waters forums. To fix that problem without drivers upgrade, they propose to set the Fill modes of my vials to Constant Volume. Any idea what volume should I use to perform pressurize my vials?

ALS on 8890 - configuration ?

Ting — Wed, 14 Apr 2021 04:26:47 GMT

Hello all,

Trying to figure out where or how to change ALS configuration on the touch pad from Front Injector to Back Injector and vice- versa?

Thanks,

Ting

Column trimming and bake out.

Agnes — Tue, 13 Apr 2021 10:09:03 GMT

Hello Everyone,

I'm very new and don't have much experience in troubleshooting the GC-MS so I need your help. I'm operating on Agilent 7890B and 5977 MSD. Recently I've noticed very big baseline noise. I have changed the inlet septum and liner, which helped a little bit, but not enough. I suspect that contamination might be already in the column so I would like to trim the column and bake it out. Could you please let me know how should I prepare the GC and MSD for this process? I know that I have to cool the oven and inlet to room temperature, but what about the MSD and gas flow? Should I vent the MSD (the column is connected directly to MSD), and what about the carrier gas (He), should I close the cylinder?

If someone would be able to help, I will appreciate this a lot.

Thank you.

Air Leakage

ztarbs11 — Mon, 12 Apr 2021 16:26:27 GMT

The compressed air tank hooked up to our GC8890 is leaking air at a very high rate, about 250psi in a couple days, and I'm unable to locate any leak at any of the connection points or in the line carrying the gas to the machine. I'm wondering if there's something inside the GC that could be leaking air? Both inlets pass the leak test. The other gases seem perfectly fine to me.

analyser gas H2, O2, co2

Az — Sat, 10 Apr 2021 04:54:20 GMT

Hello !

I'm interesting solution gas analyzer. My need analyser gas H2, O2, CO2, hydrocarbons, N2. My samples are gases and liquids. Does the Agilent have a solution for such tasks? So that it was possible to analyze gas and liquid samples on one device and at the same time there were components hydrogen, oxygen, carbon dioxide, etc. In the brochure that I downloaded from the site 5991-1561, I did not find a solution for myself.

regards, Azrael

Front inlet restriction test failure

ztarbs11 — Thu, 08 Apr 2021 16:53:51 GMT

The front inlet on my GC8890 is failing the restriction test. It passes the leak test no problem and I've done everything I can think of to fix it. I've replaced the septa, checked the gold seal, trimmed the column, baked the column, and checked the inlet liner which is fairly new. Any advice?

Thanks

FID ignition fails on GC7890B. Signal output too high 596000

SlawaKarbolin — Thu, 08 Apr 2021 06:24:17 GMT

HI Community. We have problems with ignition of FID on GC7890B. After few seconds the flame goes off and the gas flow goes down. At the same time our output signal ist very high 596000. Thanks for any information.

maximum Inlet head pressure for GC Capillary column

kong — Mon, 05 Apr 2021 04:35:01 GMT

Does GC capillary column(like a HP-1) has maximum operational inlet pressure?

I 'd like to use column at constant inlet pressure, 95psi.

GC S/SL inlet can supply upto 100psi(general GC).How about column? It also can maintain at that high pressure?

Actually I have plan to combine two columns(100mx0.25mmx0.5um and 2.5mx0.1mmx0.1um) for GCxGC.

When I use single column(100mx0.25mmx0.5um) the inlet pressure is 44psi constantly.

After combine, I have to set inlet pressure to 95psi for the same column flow with single column to compare data.

problem with ALS model 7650A when connecting with gc model 6890

well — Sat, 03 Apr 2021 13:04:19 GMT

we have problem with ALS model 7650A when connecting with gc model 6890 give error message ( the sampler unit has reported an error

internal error - out of range , operation may be retried )

we tried to update firmware for gc but the problem still present

any help to solve the problem will be appreciated

thanks

GC 6890 will not start run after injection from CTC CombiPAL

srscott — Fri, 02 Apr 2021 15:53:31 GMT

I'm trying to bring an instrument on-line for eventual Headspace analysis. It is an Agilent 6890 GC / 5973 MS with a CTC CombiPAL autosampler. Apparently, last year (before I was hired) the CTC was installed by a 3rd party vendor, It works on its own, meaning it will perform all of its functions correctly, as controlled thru ChemStation. However, the GC run will not start after injection. The vendor exchanged cables, and even replaced a control board on the PAL, but they could never get the GC to start. They suggested that the GC Main board might be the issue. When I was hired, I was assigned to work on getting the instrument up and running. I replaced the Mainboard, and the issue persists. I do not think the issue is with the CombiPAL, but rather on the Agilent side. Unfortunately, no-one here really has any experience with this unit and can offer assistance (or a lot of background). Any assistance would be greatly appreciated. Thank you in advance.

Front Injector/Detector Not Giving Results

ztarbs11 — Thu, 01 Apr 2021 18:17:07 GMT

In the middle of a sequence I ran, the front injector/detector stopped producing peaks, and those samples don't show up in my report. When I run the same samples through the back injector, I get peaks. I assumed it was maybe a mechanical issue, but the samples ran through the front injector are producing solvent (Hexane) peaks, but no sample peaks. I've never ran into this problem after a few months running the machine. I'm running a GC8890 with OpenLabCDS 2.5

8355 SCD high output

jmbrummett — Wed, 24 Mar 2021 19:36:23 GMT

I operate an Agilent 8355 SCD. The baseline output that is stated in the manual is 150pA in a well stabilized system with an oven temperature of 50C. When not in use, the baseline output is around 500pA. I'm not sure if this is caused by the method I use/frequency of use or if there is an issue with the detector itself that needs to be addressed. Any thoughts on the cause of a high baseline output?

Reproductibility

clem.lema — Thu, 11 Mar 2021 15:05:19 GMT

Hello, I have a reproducibility problem, my results vary for the same solution (but that is not taken in the same vial), I dose ethanol. I had nice peaks when creating my method and I now have rear drags that increase my result. I only changed my syringe and my hydrogen flow (because the flame was going out). Thank you for your help

error for 7890a

mahyar.fathali — Thu, 11 Mar 2021 06:52:49 GMT

there is an error on kayboard 7890a gc. this is the error ''Configuration version has changed Default configuration loaded and Workfile version changed or setpoint memory corrupt.default setpoint loaded

8355 SCD power won't stay on

ytam — Wed, 10 Mar 2021 23:43:50 GMT

I have a 8355 SCD that will not stay powered on. When you hold the switch, it turns of but it turns off when released. Does this require a new power switch? Is there a part number for the 8355 power switch?

batch start false

kadir — Sun, 07 Mar 2021 10:41:06 GMT

Merhaba

Agilent marka G1888 headspace sistemi ve 8890 headspace gaz kromatografi sistemlerinde partiye başlıyorum. Sistem aynı kolon ve gaza sahip olmasına rağmen farklı bir yöntemle farklı bir partiden sonra sistemi başlatıyoruz. Ama yaptığımız son parti sistemi almıyor. Bu sorunu nasıl çözebiliriz? Sistemlerin birbiri ardına başlaması için nelere dikkat etmeliyiz? Hplc cihazlarında herhangi bir sorun yaşamıyoruz ancak gaz kromatografi cihazında böyle bir problemle karşılaşıyoruz. Empower 3 kullanıyoruz.

DW-WAX column - analyse methanol in water:isopropanol (95:5). UNEXPECTED peak!!!

envilabeko — Wed, 03 Mar 2021 19:25:57 GMT

Hello, Im using DW-WAX column (30m, 0,53mm, 1um). I was trying to analyse methanol in water:isopropanol (95:5). I have huge problem, in my desorbent always is methanol peak and it is big.. the weidrest is that this peak in 1st inj has area about 10, next inj - peak is bigger, sometimes area 200.. then 3rd inj peak has area about 25 and over and over again.
What could be the problem? Any idea how can I remove it? The program is isotermal - 50*C for 5 min, detector temp=250*C and injector temp=200*C.

Please heeeelp!

flame problem

clem.lema — Wed, 03 Mar 2021 13:46:43 GMT

Hello,

The flame goes out as soon as the detector stabilizes at 2 pA, and it turns on again and then re-opens with my GC8860. I think the problem comes from the LIT offset value, however impossible to change this value with my interface. I have to choose [Settings]> [Configuration]> [Detector] but I don't have the [Configuration] tab (from the device's IP address).

Thanks for your help

Back Inlet pressure not Ready

Raam — Thu, 25 Feb 2021 09:19:59 GMT

Hi All

I am coming across a problem when i put a sequence of run, after the run starts when the syringe goes to wash vials it looks fine and after that sample wash looks fine, and when it comes to sample vial again to pick the sample, it stays there for long and i am getting the below message. Some times it will pick after 5 min some time it will take longer. Is there a leak

For 5 min or some times even longer it is staying there, after that it runs normal, but by displaying the same message again while it is in run.

I have attached the pressure setting an it is in constant flow,

I. I tried changing the inlet, gold seal, check the coloumn end both inlet and detector end

2. The engineer changed the EPC, still i am getting this message. I tried it with gas saver mode off as well. Any sugesiton please

GC uECD via MassHunter

ahoran — Wed, 24 Feb 2021 13:02:49 GMT

We have been running methods on 7890A/B GCs for quite some time, and recently stood up a GCMS with a 7890B as the GC. We configured the GCMS to run GC only for checkout, plumbed with our typical column and uECD detector and our typical running parameters. When checking out the system in this fashion (controlled by MassHunter instead of our normal CDS), our signals come out about 10^6 higher than we see on any other system. Does MassHunter apply some sort of multiplier when dealing with non mass spectral data?

Removing the FID detector from methods and conserving helium.

snorman — Mon, 22 Feb 2021 20:51:26 GMT

We are going to shut the FID off on all of our 5975/6890 GCMS. Is there a way to remove the FID as a detector in the methods? We have attempted to set everything to zero, but the method requires some flow. We are hoping to conserve as much helium as possible.

Gas Saver Mode - How to use it correctly

petertran — Sat, 20 Feb 2021 04:44:21 GMT

This video provides a key understanding about Agilent Gas Saver Mode. The specific question to be answered in this video is should Agilent Gas Saver Mode always be turned ON ?

https://youtu.be/gaM-itVkQEc

Peter.

6890 FID erratic makeup gas flow

MikeSJSU — Fri, 19 Feb 2021 22:49:43 GMT

One of our 6890 GC's shows a continually varying (in one minute the reading can vary up or down 20 ml/min) flow for the makeup gas. I shut down all the heated zones and turned the nitrogen flow off at the cylinder and the display on the GC still showed a flow present which of course was drifting up and down. All the other gas flows look normal. Any ideas on what could be wrong.

Problème répétabilité

clem.lema — Wed, 17 Feb 2021 15:16:00 GMT

Bonjour Agilent,

Je travaille sur dosage de l'éthanol (en pourcentage v / v) sur GC Agilent 8860. J'ai fait une droite d'étalonnage de 10% à 100% et j'ai obtenu un r² = 0.9968, jusqu'ici aucun problème. Puis, j'ai voulu passer des échantillons inconnus, lorsque je passe 3 fois la même solution j'obtiens 3 valeurs qui varient énormément (pouvant aller de 50% à 150%), je n'ai donc aucune répétabilité et je ne retrouve pas les bonnes valeurs. Avez-vous une idée d'où cela peut venir? Merci d'avance, CL