GC/MS Confirmation for positive rapid screening drug test results
GC/MS Testing 
A drug testing program is not complete without the ability to perform a gas chromatography / mass spectrometry (GC/MS) confirmatory test on positive screening test results. MD supports rapid testing programs by providing our clients with the capability to perform laboratory GC/MS confirmation test for initial positive screening results using a rapid test. GC/MS confirmation for rapid test results is available through MD at SAMHSA certified labs for urine and oral fluid samples.
GC/MS testing is an extremely accurate test that provides quantitative (numeric) results for the presence of a specific drug or drug metabolite, based on the physical and chemical properties of the specific drug or metabolite to be measured by extracting the drug from the urine and using heat or liquid to cause the metabolites to separate. GC/MS testing is considered the gold standard in drug testing and results are consistently upheld when challenged in a court of law.
One Step Sample Collection
In many cases the rapid test collection container (eg. Standard Collection Cup, Self-Contained Cup, Oral Fluid Collection Vial) may also be used to send the remaining sample to the laboratory adding no extra steps to the specimen collection process.
Cutoff levels for Immunoassay Screening and GC/MS Test
Analyte |
Rapid Immunoassay Screening |
GC/MS
Confirmation |
|
Urine |
Saliva |
Urine |
Saliva |
Amphetamines |
1000 ng/ML |
50 ng/ML |
500 ng/ML |
40 ng/ML |
Methamphetamines |
1000 ng/ML |
50 ng/ML |
500 ng/ML |
40 ng/ML |
Cocaine |
300 ng/ML |
20 ng/ML |
150 ng/ML |
2 ng/ML |
Opiates |
2000 ng/ML |
40 ng/ML |
2000 ng/ML |
10 ng/ML |
THC (marijuana) |
50 ng/ML |
12 ng/ML |
15 ng/ML |
0.5 ng/ML |
PCP |
25 ng/ML |
10 ng/ML |
25 ng/ML |
0.5 ng/ML |
Benzodiazapines |
300 ng/ML |
|
200 ng/ML |
|
Barbituates |
300ng/ML |
|
200 ng/ML |
|
Methadone |
300 ng/ML |
|
200 ng/ML |
|
Propoxyphene |
300 ng/ML |
|
200 ng/ML |
|
Limit of Quantitation Levels
Lower “limit of quantitation” levels are available for reporting at the client's option. This is the lowest level that a laboratory can legally defend the presence of a drug or drug metabolite.
|
