Quote Originally Posted by FakeBoobsRule
The GC/MS confirmation for a 50 ng/ml immunoassay cutoff is 15. There is also the 20 ng/ml cutoff on immunoassay with 10 ng/ml confirmation on GC/MS.

Now read this thread.

http://boards.cannabis.com/drug-test...ml#post1488120
Well I guess you didn't get that about the values used in testing but did you read the thread I linked because almost all the answers are there? I really don't want to have to repeat myself for the 100th time here on a holiday but here goes.

If they are using the 50 ng/ml cutoff on immunoassay then the level they will use on the confirmation GC/MS will be 15 ng/ml. See how I am using the terms cutoff, non negative, and confirmation. Technically, a immunoassay that test for a drug metabolite isn't considered positive, it is non negative then it goes for the confirmation GC/MS. You have to be below 50 ng/ml on immunoassay, not 50 or higher. Probably 95% of THC drug tests use these two values, 50 ng/ml on immunoassay then 15 ng/ml on GC/MS. Now go read the thread again I linked about the 31 metabolites. I don't know how much more I can explain that so if you're still confused maybe someone else can explain it.

The next most common values used are 20 ng/ml on immunoassay cutoff and 10 ng/ml on GC/MS confirmation.

There is also a 100 ng/ml immunassay and I don't know what the confirmation is on GC/MS. This option is out there but hardly ever used, maybe 1 in a thousand.

Most of the time when referring to the test they will refer to them as the 50 and 20 ng/ml cutoff which is talking about the values used in immunoassay, not the GC/MS. So again the corresponding values are 50 and 15, 20 and 10.