NCJ Number
133688
Journal
Clinical Chemistry Volume: 33 Issue: 1 Dated: (B) (1987) Pages: 33B-40B
Date Published
1987
Length
8 pages
Annotation
The need for employee drug testing has not been established, but if random urinalysis is done, the choice of drugs to be detected should be made carefully and quality testing and supportable interpretations should be available.
Abstract
Tests are available to identify and quantify the analytes that advocates of drug testing say should be determined. These tests include presumptive screening tests and confirming tests. Immunoassays and chromatographic methods are considered presumptive screening tests, while gas chromatography-mass spectrometry (GC/MS) can be a confirmatory procedure. The use of immunoassays, tests most often used and contested in cases involving drug testing in urine, is limited because they are designed to detect only one analyte or a few closely related ones. In any test, the identity of the measured apparent compound in the specimen should be confirmed to be the same as that of the known analyte in the reference standard. Identification and quantification should not be stated as confirmed if the calculated concentration is less than that of the lowest standard sample. Thin layer chromatography is useful for screening urine because multiple specimens can be applied to a chromatographic plate and more than one drug can be determined for each application. GC and high-performance liquid chromatography are also useful for screening. MS is used in procedures generally accepted by the scientific community for the confirmed identification of analytes. Quality control of the confirmatory method, correct interpretation of results, and proper documentation throughout the chain of specimen custody are important, particularly with regard to the admissibility of urine drug testing results in court. 54 references