For those of you who are reading this from your office, or laboratory, please do be safe and thank you for the essential functions that you continue to serve, despite the risk to you and your family. We are all grateful for your efforts. However, if you’re like me right now, you are reading this from home. While it is certainly an adjustment (how is it possible that two toddlers can sound like a herd of elephants migrating through a bubble wrap factory!?), it is very important for those of us who can, to stay home and slow the spread of COVID-19. All the same, it is probably difficult being away from your instruments, even if this is a good time to catch up on other tasks. When all of this comes to an end, and eventually we return to work, in what kind of condition will we find our instruments?
Fortunately, purge and trap systems are simple in their operation, and so are pretty robust to long periods of standby operation. If you are away from your instrument for more than a long weekend, there are a few steps that you can take to ensure a smooth startup once you return. First and foremost, you should ensure that the carrier and purge gas supplies are sufficient to last the duration of the shutdown. If gas supply is not a concern, then the instruments may be left running until you are able to return. Normal standby flows and temperatures are enough to ensure that the instruments will be ready for analysis upon your return. If gas supply is of a concern, or you wish to power off the equipment due to electrical or other concerns, then the following procedure should be followed:
- Open your GCMS software and initiate a vent cycle on the mass spectrometer. This will get the source and quads cooling in preparation for venting and powering off the MS.
- Set your inlet temperature to ambient or turn off the heater. This will ensure that the inlet is cooled under flow of clean carrier gas, and not exposed to any atmospheric contaminants while hot.
- Similarly, set the MS transfer line to ambient or turn off, if not already done so by the vent cycle.
- Once all zones are cool, and the MS is vented, power down the GC and MS and shut off carrier gas flow. If you are using a hydrogen generator for carrier gas supply, follow the manufacturer’s instructions for proper shutdown.
- Remove the column, cap both ends, and cap the inlet, as well as MS transfer line or other detector inlet. Store the column in a cool, dry location.
- Purge and Trap
- Open the method editor and create a method with all temperature zones at ambient or turned off. Load this method and allow the purge and trap to begin to cool. Like with the GCMS, this will allow the system to cool while still under a clean purge gas environment, ensuring that contamination from ambient air does not occur.
- Once cool, power off the P&T system and shut off purge gas flow. If you are using a nitrogen generator for purge gas supply, follow the manufacturer’s instructions for proper shutdown.
Once you return to work and are ready to restart the system, the following procedures may be followed for best results:
- Now is a great time to perform periodic maintenance (PM) on your GCMS system. Consider replacing the split vent filter, as well as column (if needed/not properly stored) and performing full inlet maintenance. Now would also be a great time to change out the rough pump oil, clean the source and/or replace filaments.
- (Re)install the column and reinitiate carrier gas flow. If using a generator, follow the manufacturer’s instructions.
- Power on the GCMS and initiate the pump down cycle on the MS.
- Reload you GC method to reset the temperatures of all zones to their operating conditions.
- Allow MS to stabilize and tune if necessary.
- Purge and Trap
- Now is also a great time for some PM for the P&T as well. Consider replacing the analytical trap, the syringe (if equipped) and sparger. Now is also a great time to perform any other low-priority repairs, such as replacing kinked tubing, scratched/damaged glassware, or parts with intermittent failures.
- Reestablish purge gas flow to the P&T, and power on the unit(s). if using a generator, follow the manufacturer’s instructions.
- Reload your P&T method to reset all gas flows and temperatures.
- Once GCMS is operational, consider loading a P&T sequence of 10 or more reservoir blanks assist in conditioning the new analytical trap as well as GC column. Once the baselines are settled and blanks are reproducible, normal analysis may be resumed.
I hope these tips help get your lab back up and running quickly and with as few issues as possible. And remember, our customer support team is always available to assist. They can be reached by email, TekmarSupport@Teledyne.com.
Stay safe out there