Evaluation of Triage screening for drugs of abuse in postmortem blood and urine samples

A Triage screening system that utilizes a simple and rapid deproteinizing procedure using solid sulfosalicylic acid has been evaluated in 62 blood and 27 urine samples obtained from 72 consecutive autopsy cases. Among the blood samples, 11 were positive for amphetamines (AMP), 3 for barbiturates (BAR), and 1 for opiates (OPI). Of the 11 samples that were positive for AMP, only 1 contained methamphetamine (at a concentration of 1.37 micrograms/ml). All 10 samples that were falsely positive for AMP contained phenethylamine, a putrefactive amine, at concentrations of 0.83 to 2,070 micrograms/ml. Apparent negative reactions of the Triage system for benzodiazepines (BZO), AMP, BAR and tricyclic antidepressants (TCA) were observed in three, two one and one blood samples, respectively. These drugs were present in concentrations that were much lower than the lower detection limits of the device. Among the urine samples, nine were positive for AMP, three for BZO, three for BAR, two for OPI and one for TCA. Of the nine samples that were positive for AMP, only three contained methamphetamine (at concentrations of 7.95 to 44.9 micrograms/ml) and six contained no methamphetamine but did contain phenethylamine at concentrations of 0.52 to 14.3 micrograms/ml. False positive Triage reaction were observed only for AMP. There were no false negative Triage reactions from either the blood or urine samples examined for eight classes of drugs of abuse, namely phencyclidine (PCP), BZO, OPI, cocaine metabolites (COC), cannabinoids, AMP, BAR and TCA. The Triage screening system is not able to detect therapeutic or non-toxic levels of drugs of abuse in blood or to discriminate between AMP and putrefactive amines in moderately-to-heavily decomposed blood and urine samples. However, it may still be a useful tool in the field of forensic toxicology for the following reasons: 1) the deproteinizing method causes little reduction in the sensitivity of the Triage screening device to the drugs of abuse, even in turbid urine samples, and 2) it is able to detect toxic levels of PCP, BZO, COC, OPI and BAR in any kind of blood sample.