The applications of supercritical fluid and solid-phase extraction techniques for the recovery of drugs of abuse from biological matrices

The application of Solid-Phase Extraction (SPE) and Supercritical Fluid Extraction (SFE) were evaluated for the determination of various drugs of abuse analyzed in the field of forensic toxicology. Three biological matrices (blood, urine and hair) were investigated for the recovery of various commonly abused drugs. The current SPE method used in the routine laboratory was optimized for the extraction of benzodiazepines in whole blood and applied to authentic forensic case samples. The optimized method and the routine method were than compared using authentic forensic samples. Successful methodology developed provided an efficient, less time consuming, reproducible and more robust alternative to the current routine method. The use of SFE was applied to blood and urine samples for the extraction of cocaine and its metabolites, benzoylecgonine and ecgonine methyl ester. The method developed showed that the drugs can be successfully extracted from various biological matrices such as blood and urine with comparable results to SPE methods. Forensic case samples positive for morphine were extracted using SFE and SPE techniques and the results compared. A good correlation was observed between the two methods rendering them compatible for the detection of morphine in whole blood. Hair analysis was investigated using both SPE and SFE techniques. A study was carried out to determine whether a correlation existed between self-report data and hair analysis for five amphetamines (metamphetamine, amphetamine methylene-dioxyamphetamine, methylenedioxyethylamphetamine and methylenedioxymethamphetamine). SPE methods developed proved that all five amphetamines could be extracted from human hair. However, a correlation did not exist between self-report and hair analysis data. Inter-laboratory studies carried out between two laboratories showed that both produced similar results for case samples containing amphetamines. For the extraction of amphetamines (MDA, MDMA and MDEA) and cocaine and its metabolite from hair, developed SFE methods were applied. Amphetamines in hair were successfully extracted from spiked and authentic hair samples thought to contain amphetamines using developed SFE methods. Cocaine and ecgonine methylester were also successfully extracted from spiked human hair