Accuracy of GCMS test?

[mr bridger]

I tested positive for amphetamine when my hair sample was used on a GCMS drugs test. I still do not know how this has happened and my only explanation was that I was taking ephedrine occassionally to train. As a result I was sacked from my job without any recourse. My GCMS results look very different from the diagrams I have seen on the internet, ie mine are rather wide and curved at the top, where as the diagrams I have seen appear very sharp. Could this indicate an incorrect temperature setting on the machine? could this have given a false positive? The very strange thing about the results as well is that there was no ephedrine detected, only amphetamine. I know that the metabolites are extremely similar, has anyone any ideas if the results could be wrong. Any help would be much appreciated.

 

[villian]

its possible but uncommon. Just to be clear, did you take any amphetamine? You ask if they could be wrong you aren't saying they are wrong which seems odd.

 

[mr bridger]

Thank you both for getting back to me. The reason why I am saying that they could be wrong is that if there was amphetamine in the ephedrine I was taking then I took it but not knowingly. I certainly had no adverse effects that would indicate I took amphetamine but I cannot prove this and unfortunatley the panel found me guilty of this charge. It was a disciplinary not a criminal charge so the proof does not have to be beyond reasonable doubt so I could not even get an appeal unless I could get further evidence to prove my innocence.
Regarding the use and cleaning of the machine, I have thought of that but would find it difficult to prove that as well as they are not going to admit that they did not. I wish now that I had demanded that I witness the procedure. I have read that it is common for labs not to carry out these procedures. Do you know anything about the readings of GCMS. My results in themselves look odd, that it to say they curve instead of peaking sharply. I have read that this could show that the machine was set at an incorrect temp. All I need is evidence to show doubt and I may be able to get an appeal.

 

[The Chemist]

ephedrine

This can cause a false positive for Amp, and even Methamphetamine in some individuals.

Take another test.

 

[mr bridger]

Thanks for that. I just wonder how honest the lab will be with me when I start asking for this information. Regarding the hair sample, the rest of the sample was 'damaged', I think they dropped it or burnt it, so we did not have any hair to re-test. My legal team said that it was not enough to challenge. I think this is the first in this country to certainly challenge a result and I feel that there is not enough experience in this field to challenge, hence why I want as much as I can to see if I can put a case together. I will certainly request all you have said from the lab. Thanks again.

 

[The Chemist]

you will more than likely require judicial action to gain access to that information. What would also be useful is just how many false positives come from that particular lab every year/quarter. This will help prove the fact that you are not alone and could be due to lab negligence.

 

[vecktor]

for the analysis to be valid there has to be a blank prior to your sample and after your sample and this blank must not show any analyte of interest. The classic mistake is not regularly replacing the split filter then when a sample has too much solvent volume it flashes and carries old stuff back out of the split line into the injector.

for proper identification GCMS identification requires a MS spectrum match +- 5%, and a GC retention time match +- 0.05 min against a standard on the same machine using exactly the same conditions. library matches ie no reference present are not good enough to positively ID.

you are wasting your time trying to sue here, no forensic chemist will back accusations against the lab even if the lab is blatantly wrong (there is a notorious incident where a forensic lab was sending out LCMS 'results' when they did not have a working machine for almost a year!)

if you sue and you get your job back, how long do you reckon you would last before they got rid of you or forced you to leave?
its tough luck, but just move on, even better don't work for a company that thinks it has the right to drug test you.

 

[Captain.Heroin]

So if an employer says "I am going to mandate you get drug tested", all they have to do is take some urine/hair, "burn it" or throw it away, then go get their own urine/hair tested. When theirs is testing positive for 5 different drugs, they'll just write your name on the same picture photocopied, and simply inform you, you're fired and you're a drug addict apparently too. 8)

Is this possible? Yes, yes it is.

Never accept a job which allows drug testing. Even if you don't use drugs.

I mean...as long as pissing in a cup or whatever is not your cup of tea.... if you enjoy that sort of thing be my guest.

I'm not a lab rat and I'm not going to behave like one.

 

[Hyperthesis]

^Nahhh, it is not this possible by such easy means. Your sample needs to be stored in the analysing lab and has to be checked for a second time in case that there are any justified doubts about a sloppy technical handling resp. analysing. The problem already starts though with providing a good reason that the analysis wasn't actually done properly. Comparing your chromatograms with random chromatograms found online is futile and won't be accepted, as the look depends on many factors (eg. the software used, the hardware, the practical skills of the technician, etc.). Second opinion from an anonymous internet forum won't be accepted, too. You need a professional second opinion to argue accordingly, which seems to be a little too late if you are already fired.

In case you took ephedrine laced with amphetamine and the lab indeed tested for amphetamine, well, then that's bad luck for you because technically you took amphetamine. Companies don't care if you had fake or cut material, because if there would be a medical indication for your requirement you could get genuine ephedrine with a description.

In case the lab tested for a metabolite of amphetamine and not amphetamine itself, then a false positive is possible, as both compounds share some metabolites IIRC. Again that seems a bit too late, because it should have been checked before you were given the pink slip.


I have to disagree with Vecktor! It is not this easy to refuse to work for companies, which drug-test their employees. Many notable employers in continental Europe, the UK and the US alike made this to their common practice and refusing to work for any of them equals rejecting very lucrative job opportunities. After the last huge crash at the finance markets that's tricky issue, if you ask me, being unemployed vs. working for a company, which tests you.

No idea if you get away with refusing to get tested. I can imagine that this will be interpreted as trying to hide a drug habit and leads to not getting the job anyway

 

[vecktor]

I have to disagree with Vecktor! It is not this easy to refuse to work for companies, which drug-test their employees. Many notable employers in continental Europe, the UK and the US alike made this to their common practice and refusing to work for any of them equals rejecting very lucrative job opportunities. After the last huge crash at the finance markets that's tricky issue, if you ask me, being unemployed vs. working for a company, which tests you.

No idea if you get away with refusing to get tested. I can imagine that this will be interpreted as trying to hide a drug habit and leads to not getting the job anyway

it is a simple choice, sometimes people need to look beyond the money, if the company sees it as OK to invade their employees privacy and behave like they own you then what else do they think is OK?. If that is their attitude then do you really want to be part of that? If you do buy in to that BS then fine but then don't take drugs get caught and bitch here about how unfair it all is.

About 10 years ago I was at a company that was taken over by an American corporation who rocked up with this stupid drug testing idea, the current staff refused to reapply for their jobs and so didn't have to do any of the drug testing and other BS the US company thought was a good idea, whereas the shipped in Americans and new employees ended up being drug tested and also had less holiday and benefits.

In the scientific field nobody really drug tests, its dumb because the people being tested know more about it than the people doing the testing, nobody tests medics either.

 

[Hyperthesis]

it is a simple choice, sometimes people need to look beyond the money, if the company sees it as OK to invade their employees privacy and behave like they own you then what else do they think is OK?. If that is their attitude then do you really want to be part of that?

It doesn't count so much what I what than what I have to, as I need to accept even such job offers if nothing else is available. It would definitely piss me off, but still better than being unemployed and without any money at all

If you do buy in to that BS then fine but then don't take drugs get caught and bitch here about how unfair it all is.

No discussion about that, Sir. If somebody gets caught in such a situation he better stops the drugs or spares us his complaints.

 

[mr bridger]

Thank you both for your replies. The job I had I did for 24 years and loved every minute of it so it is hard to except any decision. I feel that maybe my legal team did not know enough about drugs testing in the lab as questions were never asked regarding clean testing prior to actual test etc. My next line of enquiry will be what records must they keep to show these tests have been done, if at all.
Appreciate your comments though.

 

[Hyperthesis]

My next line of enquiry will be what records must they keep to show these tests have been done, if at all.

Good idea.
And maybe post your test results here, so that we can have a closer look at it (personal data edited out, of course!!!). Maybe that helps to see HOW they actually tested, and WHAT they were looking for.

 

[Beenhead]

With GCMS, the retention time and the fragmentation pattern would be different with Ephedrine vs Amphetamine.

If you get your ephedrine from a reputable source, not off the street, then you should not have cut product. If you get it off the street you got busted.

IF the peaks in the GC trace are not sharp, and are curved, this is symptomatic of a bad column. But this is not going to cause a false positive, since you must have amphetamine in the machine to get an amphetamine trace.

If you have not taken amphetamine, then the most likely answer is amphetamine that is stuck in the column, the sleeve where the injection occurs, or in the split line.

If you find a great job, but they drug test, I would say quit drugs, since it is better to be in a great position financially and professionally than be able to take drugs with no worry.
If your job is one where others lives are in your hands, I think its a great idea to test...

You just have to weigh the pros and cons. I dont think you can be as cut and dry as if they test dont apply.
Just because they drug test does not mean that the company is evil and they think they own you. They just may not want drugs apart of their workplace. It is their company, its their choice if they want someone doing drugs working for them. Just like it is your choice that you work for a company that drug tests. There is nothing despicable about either one in my opinion. I like drugs, my boss does not. I dont see the huge conflict in humanities interest there.

Since I work with GCMS all the time, I know what it is capable of. I really dont see it as being all that likely that it was a mistake. Operator error couldnt really cause it, unless they injected the wrong sample. Library searches dont really make mistakes, and a GCMS can easily tell the diff between Amphetamine and ephedrine. It sounds like youre ephedrine was spiked with amphetamine.