Drugs of abuse testing by tandem mass spectrometry: a rapid, simple method to replace immunoassays.

Abstract Primary objective To replace immunoassay screening for drugs of abuse (DOA) with a cost-effective tandem mass spectrometry method. Secondary objective To substantially expand the drugs of abuse assay menu. Design and methods The requirement was to perform high throughput DOA screening for 200 urine specimens/day for 40 drugs/metabolites. The total analysis time had to be Results 40 different drugs were separated by UPLC™ (ultra pressure liquid chromatography) with a run time of 5.2 min. Detection limits were below our cut-off values. Individual drug species instead of drug classes were identified; correlation with GC/MS was excellent. A high throughput, robust assay with acceptable accuracy, precision and specificity was developed. The procedure can also be used as a quantitative method with simple modifications. Conclusions An improved, high throughput, cost-effective method for drugs of abuse screening has been implemented. GC/MS confirmations were reduced or eliminated. The new procedure is a viable alternative to our previous immunoassay method. Acceptable turn around times, an expanded menu, simplified sample preparation and analytical reliability makes this method a desirable option in the clinical laboratory setting.