Passed an EMIT at 50 ng; worried about a GC/MS test

Discussion in 'Urine Testing' started by TiJ, Aug 3, 2013.

  1. TiJ

    TiJ New Member

    I recently had a pre-employment urinalysis screen. It was 5-panel, 50 ng. EMIT followed by GC/MS for confirming preliminary positives.

    In anticipation of the test, I stopped smoking two weeks prior. My usual habit of several years is to have a small half-tobacco spliff per day, skipping a day here and there. I end up using about a gram per week, and am slim, weighing 175 at 6'3". Following advice on this forum, I began home-testing myself once I learned of the upcoming screening. A week after my last day smoking, I failed a test. I believe there was a faint, faint, faint line indicating negative, but I was really looking for it. I'm talking about 5% opacity--could well have been a fail and I just wanted to see the line so bad that I wished it were there. I know "any line is a pass," but this was... basically I'd say it wasn't a pass. I was pretty close to the cutoff though, given that 4 days later, I took another at-home test, and passed. A day or two after that, I took another, passed again. The night before the actual test, another pass. The afternoon of the test, I again passed at home. I used several brands of test to rule out the possibility of a false negative. So I had 4 negatives in the week leading up to the test. I decided against dilution--I had an extra glass of water or two the day-of, but I wanted to avoid appearing to have intentionally diluted, since I was doing well so consistently without it.

    Now, here's the twist. I'm confident I passed the initial test for THC. However, I also take a prescription drug, legitimately, under the care of a doctor. I do not abuse it, and it is done legally at my physician's urging. It is one of the 5 drugs tested for in a 5-panel test. (I'm avoiding saying which one it is, as I think the rules here are to not discuss other drugs, but as this is alegit use of medicine and is relevant to my question, which primarily concerns THC, I'm disclosing the info).

    When I went for my actual screening, I brought my script for the medicine. My intent was to give it to the tech there, have her mark it on my file, and avoid the possibility of having my sample being sent to GC/MS to confirm the positive result for this substance. However, she rejected it, saying, "It's not our business. If we find anything in your sample, the MRO will call you and you can give him the prescription information then."

    So now I'm concerned. I think it's about 95% likely I tested negative for THC on the EMIT test, and probably just as likely I was positive for the other (legal! doctor-prescribed!) substance. If and when they send my sample to the lab for the confirmation test, I believe it's probable that I will still be above the 15ng cutoff for THC that the second test uses. Again, I am not concerned about the presence of the other drug in my system, and will be able to provide documentation and my doc's contact info. What I AM concerned about is that this other substance may initiate a more-accurate GC/MS test, which could then reveal the THC (over 15ng, but under 50 ng).

    Is anyone aware of the likely outcome in this scenario? Will the lab only be looking for the substance that I had an initial positive on, or will they do GC/MS for all five drugs that were being tested for in the first place? I am wondering because as I understand, GC/MS is done to CONFIRM the results of an EMIT. If test #2 doesn't show the same result as test #1, is that considered "confirmation," or is it a scenario in which I'd be asked to provide another sample because the results of the two tests don't sync up?

    Any insight is appreciated, and I hope that my including the information about my medication doesn't violate the rules of this site. Thanks for your help.
  2. TiJ

    TiJ New Member

    Update: Got a call from the MRO today–he said, to my immense relief, that he’d found something in my sample which he guessed was Adderall (it was). I told him what I’d hoped to explain to the nurse in the first place: I am prescribed it and take it under the advice of a doctor. He was very polite and asked me to take a photo of my script, email it to him “and then we’ll be able to get all this finished up for you”. Sent him what he asked and got another call a few hours later saying I was all set and he’d told my future employer that my sample was clean and negative. I feel like a million bucks.
    Lesson learned. I’m slim and while I don’t “work out”, I hike often. As I mentioned up thread, while I smoke about 5x/week, it is a small amount at once (a gram or possibly a bit more per week, for years). If you’re in the same camp, you may also be able to get clean enough to pass a urine test by totally abstaining for two weeks. I’m not sure if the GC/MS test that was used to confirm the amphetamine in my system just wasn't *able to* detect any THC metabolites, or if the GC/MS was only used to *find the specific substance* that was found in the EMIT. Either way, I’m elated and I hope anyone who faces a similar situation can gain some small amount of solace from my freakout. My advice: stop smoking immediately, get exercising until a few days before the test, and above all, stay calm. I have been so stressed about this it’s kept me up nights and I only wish I had been a bit more levelheaded and less irritable in the past few weeks.

    Best of luck!
  3. Buzzby

    Buzzby Buddhist Curmudgeon

    The 50 ng/ml threshoyld on an immunoassay test as actually equivalent to the 15 ng/ml threshold on the GC/MS. This is because the immunoassay test reacts to 32 different cannabinoids. The GC/MS measures only to THC.
  4. TiJ

    TiJ New Member

    Buzzby, thanks. Based on my experience and your clarification, that makes complete sense. There is a lower threshold for the more expensive GC/MS test, but it's only looking for one of a number of THC metabolites, whereas the EMIT is looking for ALL of them, and thus has a higher cutoff. Simply knowing this would have set my mind at ease in the past week -- hopefully, someone else will read this thread and learn from it.

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