Comparison and Evaluation of DRI® Methamphetamine, DRI Ecstasy, Abuscreen® ONLINE Amphetamine, and a Modified Abuscreen ONLINE Amphetamine Screening Immunoassays for the Detection of Amphetamine (AMP), Methamphetamine (MTH), 3,4-Methylenedioxyamphetamine (MDA) and 3,4-Methylenedioxymethamphetamine (MDMA) in Human Urine*

Abstract

The performances of four immunoassays (DRI amphetamines, DRI ecstasy, Abuscreen ONLINE amphetamines, and a modified Abuscreen ONLINE amphetamines) were evaluated for control failure rates, sensitivity, and specificity for amphetamine (AMP), methamphetamine (MTH), 3,4-methylenedioxyamphetamine (MDA), and 3,4-methylenedioxymethamphetamine (MDMA). The two DRI reagents and the ONLINE reagents were run according to manufacturer specifications using a Roche Hitachi Modular DDP system. The modified ONLINE reagent was calibrated with MDMA and had 16mM sodium periodate added to the R2 reagent. These assays were run on approximately 27,500 human urine samples and 7000 control urine samples prepared at 350 and 674 ng/mL over the course of 8 days. All assays were calibrated using a single point, qualitative cutoff standard with the manufacturer-recommended compound at the Department of Defense cutoff (500 ng/mL). Gas chromatography-mass spectrometry (GC-MS) confirmation was conducted on screened-positive samples. Control performance for the manufacturer recommended assays was excellent, with a maximum qualitative control failure rate of 2.03%. The modified ONLINE reagent demonstrated poor control performance with a maximum failure rate of 38.3% and showed no improved MDMA sensitivity when compared with the ONLINE reagent; the confirmation rate (20%) was improved when compared with the production ONLINE reagent (8%). The DRI ecstasy reagent provided improved sensitivity for MDMA as compared with the ONLINE reagent, with approximately 23% more samples screening and confirming positive for MDMA and a confirmation rate of approximately 90%. The DRI methamphetamine reagent had a low confirmation rate (6% or less) and produced numerous positives for samples with only ephedrine or pseudoephedrine present.

Direct ELISA kits as a sensitive and selective screening method for abstinence control in urine

“…Studies showed cross-reactivity for the amphetamine immunoassay tests with endogenous amines or other amphetamine-like substances, e.g. ephedrine [4][5][6][7][8]. Lowering the limits for amphetamine and designer amphetamines to 50 ng/ml as done so in the updated version of the assessment criteria for driving ability was seen as a huge challenge for immunological tests.…”

“…Cross-reactivity between amphetamine tests and endogenous substances or drugs is a well-known problem [4][5][6][7][8]. There has even been discussion if immunoassay is an appropriate method in general related to the new requirements.…”

DART‐MS for rapid, preliminary screening of urine for DMAA

“…[23,55,56] Although the data presented represents a limited number of samples, DART-MS analysis has been employed for other more diversified compounds, with broadly similar results. [23,55,56] Although the data presented represents a limited number of samples, DART-MS analysis has been employed for other more diversified compounds, with broadly similar results.…”

“…Ultimately, preliminary testing methods are evaluated on their ease of use, cost, throughput, and numerous performance characteristics, such as limits of detection cut-offs and specificity/ cross-reactivity. [23,55,56] Although the data presented represents a limited number of samples, DART-MS analysis has been employed for other more diversified compounds, with broadly similar results. While these data represent an interesting alternative method for urine screening, numerous factors would affect such testing and would need to be studied in detail and validated before adoption of such as technique, including the ionization potential of the analyte and how the concentration of matrix components could affect DART ionization.…”

Novel Biomarkers of Prenatal Methamphetamine Exposure in Human Meconium

“…Immunoassay testing is quick and economical, but susceptible to cross-reactivity with compounds structurally similar to the target compound 16-19. For this reason, the identities of compounds triggering positive immunoassay results must be confirmed by a more specific technique, most often gas chromatography/mass spectrometry (GC/MS) or liquid chromatography/mass spectrometry (LC/MS).…”