Strand D.H., Berg T., Leirseth I., Christophersen A.S.

National Institute of Forensic Toxicology, P.O. Box 495 Sentrum N-0105 Oslo, Norway

Buprenorphine (B) and norbuprenorphine (NB) have earlier been confirmed at our Institute using a time consuming method, often combined with stability problems. The former method included acid hydrolysis at 110° C of 3 mL urine sample, followed by solid phase extraction and PFPA derivatization. The acid hydrolysis resulted in degradation of both B and NB with loss of methanol, often combined with dirty extracts and unstable derivatization products. The method was modified to use enzymatic hydrolysis at 37° C over night with only 1 mL urine sample. After solid phase extraction and evaporation, B and NB are now derivatized with PFPA at 30° C. With this procedure, degradation with loss of methanol is avoided, resulting in stable derivatization products and more cleaner extracts with increased sensitivity. The samples are analysed at HP GC/MS system, with a 12 m non polar column, select ion monitoring mode, and electron impact 70 eV. At the moment, our cut-off level is 0.010 µmol/L for both B and NB, but lower sensitivity can be achieved.