Method validation of the biochip array technology for synthetic cannabinoids detection in urine

Area of Science:

• Forensic Toxicology
• Analytical Chemistry

Background:

• Synthetic cannabinoids (SC) are frequently abused drugs.
• Traditional immunoassays struggle to detect SC, complicating drug screening.

Purpose of the Study:

• To validate the first commercial immunoassay for detecting synthetic cannabinoids in urine.
• To assess the assay's performance characteristics, including sensitivity, specificity, and efficiency.

Main Methods:

• Validation of a high-throughput urine immunoassay for SC detection.
• Determination of limits of detection, imprecision, and cross-reactivity with 22 SC and 37 metabolites.
• Performance evaluation using LC-MS/MS confirmation on 20,017 urine specimens.

Main Results:

• Initial assay showed high sensitivity (98.3%) but low specificity (48.1%) and efficiency (53.9%).
• A significant negative bias (-80.8 to -28.0%) was observed.
• Optimizing cutoff concentrations enhanced performance to 87.6% sensitivity, 85.2% specificity, and 85.4% efficiency.

Conclusions:

• The validated high-throughput urine SC assay demonstrates good sensitivity.
• Modified cutoff concentrations substantially improve the assay's specificity and efficiency for detecting synthetic cannabinoids.