How to Clean the HES (High Efficiency Source)

Created by Carlos Vargas over 1 year ago | Last modified by Carlos Vargas 1 month ago

This Information Applies To: Agilent HES source, Agilent 5977 Series GC/MSD

Issue:

During normal operation of the GC/MSD, the source will require cleaning. It is time to clean the source when:

There is a loss in analyte response not improving by GC inlet, or column servicing
Poor calibrant ion peak shapes during tuning.
Increasing repeller or electron multiplier voltages.

Proper cleaning, assembly, and installation are essential to robust and reliable operation.

Tools needed:

Gloves
Beakers
Ultrasonic bath sonicator
Alumina powder (p/n 393706201)
Cloths, clean, 15 pack (p/n 05980-60051) or 300 pack (p/n 9310-4828)
Cotton swabs (p/n 5080-5400)
De-ionized water
Reagent grade methanol
Reagent grade acetone
Reagent grade hexane

Steps to follow:

Remove the source from the analyzer
Disassemble the source and collect the parts to be cleaned (see Figure 1). These are the parts that contact the sample or the ion beam, the other parts normally do not require cleaning but if the contamination is serious then consider replacing the parts.

Figure 1. HES parts to clean.
Make a slurry or paste of the alumina MICROGRIT supplied with the instrument by adding de-ionized to a small amount of alumina MICROGRIT on a lint free cloth.
Abrasively clean the parts utilizing cotton swaps or lint free cloth with paste to remove all discoloration from the parts. (See Figure 2)
Figure 2. Abrasively clean the parts with the alumina MICROGRIT slurry Small scratches will not harm performance and polishing is not necessary.
Rinse away all abrasive residue from all parts with de-ionized water until the solution is clear. (See Figure 3)

Figure 3. Rinse away all abrasive material until the solvent becomes clear. If solvent is cloudy then replace with new solvent. Utilize multiple washes if necessary.
Ultrasonically clean the parts 5 minutes each in sequence of; de-ionized water, reagent grade methanol, reagent grade acetone, reagent grade hexane moving the parts to a new beaker for each solvent.
- If a solvent becomes cloudy during sonication replace the solvent and repeat the sonication.
Remove the parts from final solvent and re-assemble the source
- Take time to inspect other parts of the source to verify that the insulator is not cracked and that the filament wires are not broken and have an even thickness and shape.
Reinstall the source into the analyzer and pump down the system to reduce the amount of water condensation on the source.
- The source will be heated and under vacuum, which will remove any excess solvent.
Wait at least 1 hour after the analyzer has pumped down before confirming with a manual tune that the GC/MSD is leak tight.
If the system is leak free, then load the working method and tune file. Leave the system overnight, or complete a system bake out with the source at 300C and the quadrupole at 175 °C for at least 3 hours before attempting to tune the system.