Forensic-Employment Testing Procedures

For certain clinical or chemical-dependency treatment patients confirmation testing may not be indicated or routinely performed. Please call Drug Testing Client Services to make arrangements for such testing.

PeaceHealth Laboratories maintains strict chain of custody documentation throughout collection, testing and final storage. Drug test results are certified prior to reporting. Positive urine specimens are kept frozen under chain of custody for at least one year.


Gas chromatography/mass spectrometry (GC/MS) is considered the “gold-standard” for confirmation of initial urine drug screening procedures because it is the most sensitive and specific method. GC/MS essentially shows a “fingerprint” of the drug by determining its chemical structure. Many states require confirmation of positive tests prior to reporting the result when used for employment-forensic purposes. PeaceHealth Laboratories uses GC/MS to confirm every specimen that tests positive on the initial drug screen. Alcohol is screened by an alcohol dehydrogenase method and confirmed by gas chromatography.

Considering the serious consequences of a false positive result to both the employee and employer from less accurate confirmation methods, it is vital the laboratory provide scientifically defensible testing with extremely rapid turnaround time. When GC/MS confirmative testing is used by highly qualified, experienced personnel coupled with proper collection, transportation and reporting procedures, false positive test results will not occur.

PeaceHealth Laboratories