Comparison of Drugs of Abuse Detection in Meconium by EMIT(R) II and ELISA

Abstract

The results of meconium specimens and fortified samples screened for drugs of abuse by both enzyme multiplied immunoassay technique (EMIT((R) )II) and enzyme-linked immunosorbent assay (ELISA) methods were compared. The sample preparation for the ELISA screen was a simple buffer extraction versus a lengthy and more laborious sample preparation procedure for the EMIT II screen. The ELISA method was automated using a TECAN Genesis. The EMIT II analysis was automated with an Olympus AU400e. The opioid screen was calibrated with hydromorphone and the benzodiazepine screen was calibrated with clonazepam to maximize detection for these analytes. Previously validated gas chromatography-mass spectrometry (GC-MS), two-dimensional GC-MS, or liquid chromatography-tandem MS methods were used for confirmation. Results from the two techniques compared well. Agreement of the ELISA assay was greater than 90% when compared to EMIT II for all drug classes except barbiturates and benzodiazepines. ELISA appears to be more sensitive than EMIT II for the detection of amphetamines, methadone, propoxyphene, and cocaine. ELISA compared well to EMIT II for cannabinoids, opioids, and PCP. Specificity of the ELISA assay was slightly better for PCP and opioids. EMIT II appears to be more sensitive for the detection of barbiturates and benzodiazepines. The ELISA method reduced turnaround time by 50% compared to the EMIT II method.

Semi-quantitative analysis of drugs of abuse, including tetrahydrocannabinol in hair using aqueous extraction and immunoassay

“…Applications for complex matrices such as blood [7], meconium [8], bone marrow [9] as well as the more usual oral fluid [10,11] and urine [12] have been extensively reported in the scientific literature. Here, the utility of an aqueous extraction has been applied to the analysis of drugs in hair, which includes THC for the first time.…”

Retrospective analysis of the diagnostic yield of newborn drug testing

“…Meconium samples were analyzed by a reference laboratory (ARUP Laboratories) using enzyme-linked immunosorbent assay (ELISA) with confirmation by gas chromatography/mass spectrometry (GC/MS) or liquid chromatography tandem mass spectrometry (LC/MS/MS) testing [16, 17]. Results were only reported if the ELISA and confirmation methods agreed, eliminating likelihood of false positives.…”

Umbilical Cord Tissue and Meconium May Not Be Equivalent for Confirming in Utero Substance Exposure

“…All provider-ordered toxicology testing was performed by a national reference laboratory (Associated Regional and University Pathologists [ARUP], Salt Lake City, UT) using a combination of immunoassay and chromatography-mass spectrometry techniques (18,(23)(24)(25)(26)(27). Both UCT and MEC tests were commercially available but were performed using different methodologies and had different limits of drug detection.…”