Analyzing blood serum for opioids, cocaine and metabolites is a routine task in forensic laboratories. The most commonly used methods involve several manual or partly-automated sample preparation steps such as protein precipitation, solid phase extraction, evaporation and derivatization followed by GC/MS or LC/MS determination.
In this study a comprehensively automated method is compared with a validated, partly-automated routine method. Following manual protein precipitation, the automated method relies on a MultiPurpose Sampler (MPS) to perform all remaining sample preparation steps. These include solid phase extraction (SPE), evaporation of the eluate, derivatization and introduction to the GC/MS. Quantitative analysis of close to 170 serum samples, as well as more than 50 samples of other matrices like urine, different tissues and heart blood, was performed using both methods. Cocaine, benzoylecgonine, methadone, morphine, codeine, 6-monoacetylmorphine, dihydrocodeine and 7-aminoflunitrazepam were determined quantitatively and the methods were found to produce equivalent analytical results even near the limits of quantification [1].
