title: A comparison of enzyme immunoassay and gas chromatography/mass spectrometry in forensic toxicology.
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 negative 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 beta-glucuronidase.
mesh_terms: D001569:Benzodiazepines / Q000652:urine; D011431:Dextropropoxyphene / Q000652:urine; D005069:Evaluation Studies as Topic; D005554:Forensic Medicine; D008401:Gas Chromatography-Mass Spectrometry; D013287:Illicit Drugs / Q000652:urine*; D007124:Immunoenzyme Techniques; D009113:Muramidase / Q000652:urine; D004364:Pharmaceutical Preparations / Q000652:urine*; D011507:Proteinuria / Q000652:urine; D014116:Toxicology
chemical_list: D013287:Illicit Drugs; D004364:Pharmaceutical Preparations; D001569:Benzodiazepines; D009113:Muramidase; D011431:Dextropropoxyphene