Urinary amphetamines, benzodiazepines and methadone: cost-effective detection procedures

Area of Science:

• Clinical Chemistry
• Toxicology
• Analytical Chemistry

Background:

• Urine drug screening is crucial for clinical and forensic toxicology.
• Existing immunoassay methods can be costly and may require optimization for high-throughput analysis.
• Syva EMIT reagents and centrifugal analyzers offer potential for cost-effective drug detection.

Purpose of the Study:

• To develop and evaluate cost-effective immunoassays for detecting amphetamines, benzodiazepines, and methadone in urine.
• To assess the precision and throughput of the developed method.
• To compare the performance of the developed method with a commercially available system.

Main Methods:

• Utilized Syva EMIT reagents and a Cobas Bio centrifugal analyzer for immunoassay development.
• Assayed up to 2470 samples per 100-test EMIT kit.
• Determined mean coefficients of variation (CVs) at threshold levels (300 µg/l).
• Compared results with the Abbott TDx system and evaluated the effect of heat treatment.

Main Results:

• Achieved acceptable precision with mean CVs ranging from 3.8-6.6% for target concentrations.
• Demonstrated good correlation with the Abbott TDx system for methadone detection.
• Observed less favorable correlation for amphetamines and no useful correlation for benzodiazepines.
• Heat treatment did not significantly impact benzodiazepine and methadone detection but decreased amphetamine detection by 14%.

Conclusions:

• Developed cost-effective immunoassays for urine drug screening using EMIT reagents and a centrifugal analyzer.
• The method provides high throughput and acceptable precision, particularly for methadone.
• Further validation or alternative methods may be needed for amphetamines and benzodiazepines due to correlation issues.