Chromatography Forum

Hi, I just learned some background related to GC-MS ( Thanks to James Ball and other great teacher). Now I have the instrument in front of me, and I need to get started.


My question is : I am sure that the instrument is TUNED and linked by engineer to each other, I also believe I will be the first person use in it. The problem is the company provide no free training ,,, so I need help step by step from operating the instrument untill introducing the sample.

Something like : switch on the instrument , heat the compartment , check this and this.


Level: not bad just started.


Thanks in advance

Thats kind of a tall order. Have you run other GC/MS purge and trap methods? If no I feel you should get some on site training even if your employer has to pay for it.

One question is what type of samples are you running? Regulated compliance samples require different levels of QC than do in house research samples.

In house samples can get by with the standard tune built into the instrument software, EPA methods require the instrument be tuned to meet their requirements when injecting Bromofluorobenzene, for volatiles analysis.

I have never ran the Thermo instruments, and only the old 2000 and 3000 Tekmar models, so I am not much help on those.

A GC/MS system should always be left on and under vacuum so you shouldn't have to begin with startup of the instrument as a normal operating function. You can do into as much detail as you think you need, even to the point of what icon on the desktop to click to open the software. Most though will cover the basics of preparing the sample and standards, putting them on the purge and trap autosampler(or individual injections if no autosampler). Followed by programming a sequence into the autosampler and the GCMS control software(since for purge and trap they are usually not linked). Then finish with instructions on data reduction and reporting.

Learn the mechanics of it from the instrument manuals, then write up a summary of just how you do it. If you search, some labs have SOPs listed online, especially state run labs, and you can use those as guidance to get started. If you are totally new to the work, just start clicking on screen and pushing buttons, most things that would do harm come with a warning. I learned most of what I know from just pushing and clicking and seeing what happened, some people are too shy to try that though Training classes are great and take as many as you can get someone to pay for, but you will still have to start just going at it to really get comfortable with it.

Sorry for delay I think my question caused virus to my LAPTOP

Thanks indeed my mentors for your valuable advice.

Thanks James, I like pressing the button too, to find out and learn by mistake. I think it is the best way.

One think I am worry about is the gas cylinder , do I open the gas valve to the end and just regulate the amount from the software ( 1 ml/min ) or is there is a limit such as open just to certain pressure. I hate to be said ' he was a nice guy'.

Unfortunately to pay someone will take nearly three months for him to come and train us.

You should have a two stage regulator for your He supply set to the required pressure, (~ 100psi or 7 bar)
Leave it on except to change out scrubbers or fix leaks.

You should have a two stage regulator for your He supply set to the required pressure, (~ 100psi or 7 bar)
Leave it on except to change out scrubbers or fix leaks.

Yes, there should be something listed on the instrument or the manual about max incoming pressure. Older instruments were around 60psi newer ones are around 100-120psi I believe.

Leave the carrier gas flowing and the column at a mid level temperature in standby for the easiest startup the next time you use it. Keeping the column cold will lead to buildup of trace hydrocarbons that you will need to bake out before you run more samples. Even with the best trap in the line I have seen this happen, you just can't get every trace out of all the lines needed on an instrument. I usually leave my instruments at 120-150c in standby for volatiles analysis.

Not sure who your supplier is, but when we purchase a new instrument we are required to provide a site readiness statement. They give us a checklist of site requirements which need to be met before installation. This includes a gas line regulated to the correct pressure range.

this is a silly situation. You are not going to get by on bits of help with message-boards - or at least you run a high risk of getting bad results. You need proper training.

this is a silly situation. You are not going to get by on bits of help with message-boards - or at least you run a high risk of getting bad results. You need proper training.

^^^what he said...talk your boss into sending you to school. you can figure it out on your own, but you will probably lose your mind doing so...in the meantime, tell us what kind of gear you have (for those of us who missed that part) I have 2 Thermo GCs, 4 Agilents, and a Perkin elmer, with 4 different data station packages... maybe I can help.

Hi, Thanks guys I took your advice into consideration about the Income pressure to the system. Now every things work Ok and we were able to analyse some samples and validating the methods.

When I worked in a regulated lab we had SOPs for the set-up and operation of all our instruments.

They all consisted solely of:

1. Refer to the operator's manual.

Which would probably have worked in this case.

Peter