"INTERPRETATION: AmphetamineBarbituratesBenzodiazepinesCocaineOpiat esPhencyclidine (PCP)THC (Marijuana) MetaboliteMessageDrugs are screened by immunoassay.

Positive results are confirmed by a second method. The following threshold concentrations are used for this analysis:

DRUG SCREENING THRESHOLD amphetamines 300 ng/ml barbiturates 300 ng/ml benzodiazepines 300 ng/ml cocaine metabolite 150 ng/ml opiates 300 ng/ml phencyclidine 25 ng/ml marijuana metabolite 20 ng/ml methadone 300 ng/ml methaqualone 300 ng/ml propoxyphene 300 ng/ml"

It appears that for the GC/MS test they will test at these levels. For the standard immunassay test the cutoff should be 50.