Commonly Practiced Quality Control and Quality Assurance Procedures for Gas Chromatography-Mass Spectrometry Analysis in Forensic Urine Drug-Testing Laboratories.

Forensic urine drug-testing laboratories operate in a prescribed scientific and administrative manner to ensure accurate test results. All specimens positive by an initial immunoassay test must be confirmed by gas chromatography/mass spectrometry (GC/MS). To provide adequate control and verification of these analytical processes, laboratories must implement appropriate policies and procedures to be used in routine practice. This review describes the following topics regarding GC/MS analyses: method validation, instrument performance, assay calibration, quality control, criteria for designating a positive test result, sample and batch acceptance criteria, and GC/MS data review.