Simultaneous Determination of Methadone, Heroin, Cocaine and their Metabolites in Urine by GC‐MS

Abstract

A gas chromatographic‐mass spectrometric (GC‐MS) method for the determination of methadone, heroin, cocaine, and their metabolites in urine using Selected Ion Monitoring (SIM) was developed. Following a liquid‐liquid extraction with Toxitubes A^® and using their deuterated analogs as internal standards, the analytes were derivatized with 99:1 (v/v) N,O‐bis‐trimethylsilyl‐trifluoroacetamide/trimethylchlorosilane and injected by hand, in the splitless mode, at 240°C and a purging time of 0.75 min. The mass selective detector was kept at 300°C and molecules were ionized in the electron impact mode, using an energy of 70 eV. The detector response was linear for all drugs studied over the range 50–1000 ng/mL.

Keywords:

• Drugs of abuse
• GC‐MS
• urine
• liquid‐liquid extraction
• derivatization

Financial support of CICYT (Project BFI2002‐03385) of the Spanish Government is gratefully acknowledged.