ISSN: 0022-1198
CODEN: JFSCA
Published Online: 1 April 1980
Page Count: 6

A Comparison of Enzyme Immunoassay and Gas Chromatography/Mass Spectrometry in Forensic Toxicology
Bermes, EW
Associate director of clinical laboratories, Loyola University Medical Center, Ill.

Fenton, J
Director of chemistry, Crozer-Chester Medical Center, Pa.

Schaffer, M
Chief toxicologist and senior toxicologist, Fishbein Institute of Forensic Medicine, Ill.

Chen, NW
Chief toxicologist and senior toxicologist, Fishbein Institute of Forensic Medicine, Ill.

(Received 21 April 1979; accepted 11 August 1979)

Abstract

A series of 137 urine samples were analyzed for drugs of abuse by enzyme immunoassay (EMIT® and by gas chromatography/mass spectrometry (GC/MS). Agreement between these methods was excellent and ranged from 93.4% for benzodiazepines to 98.5% for propoxyphene. EMIT false negatives were traced to the presence of elevated endogenous lysozyme or other interfering materials. In the case of moderate amounts of lysozyme the use of a blank would lead to correct results. Disagreement in the identification of nine benzodiazepine samples was found to be due to a low recovery of benzodiazepine metabolites from urine. Recovery could be improved by incubation of the urine sample with the enzyme/3-glucuronidase.

Keywords:
toxicology, chemical analysis, immunoassay

Paper ID: JFS12128J
DOI: 10.1520/JFS12128J
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