Alternative methods of analysis for the forensic determination of cocaine and benzoylecgonine

摘要

Forensic science is always looking for new methods to aid in the analysis of drugs in biological matrices. It also searches for non-invasive methods of sample collection and analytical techniques using solvents benign to the analyst and environment or those allow- ing reduced solvent consumption. Since cocaine is the drug most encountered in forensic analysis, it was chosen for experimentation with new analytical techniques.;Column switching is a technique used in the separation of drugs from biological mixtures. Our adaptation in combination with solid phase extraction technology used one pump, column and mobile phase to affect an analysis typically using much more instrumentation. The result was a rapid yet simple quantitative technique useful for the determination of cocaine and its major metabolite benzoylecgonine in serum and urine. The technique was further validated using lidocaine and its metabolites in a pharmacokinetic study. The technique, however, lacks the conclusive identification needed in courts.;Supercritical fluid extraction, an adaptation of supercritical fluid chromatography, has the capability to extract cocaine and benzoylecgonine from many biological matrices with greatly reduced time and solvent requirements. This technique was used to extract cocaine and benzoylecgonine from blood, urine and hair. Hair was used as its sampling is non-invasive and it could become as important as urine for determination of drug use. Besides the variety of tissues compatible with SFE, on-line derivatization of benzoylecgonine is possible, making confirmatory testing very simple. This technique decreases solvent consumption and uses carbon dioxide as the major solvent. The weakness of the method is the inability to complete quantitative analysis. This is likely a function of matrix effects and extraction vessel dynamics rather than a flaw with SFE, and the rapid development in the field should overcome this problem.