A COMPARATIVE-STUDY OF DIFFERENT SOLID-PHASE EXTRACTION PROCEDURES FOR THE ANALYSIS OF ALKALOIDS OF FORENSIC INTEREST IN BIOLOGICAL-FLUIDS BY RP-HPLC/DIODE ARRAY

Different Solid Phase Extraction (SPE) procedures are studied for the pretreatment of urine, blood plasma and serum samples, for the analysis of alkaloids of general clinical-toxicological interest. Various SPE cartridges, extraction conditions and solvents were used in the search of the best recovery and clean-up. In the whole study the internal standard was used as a chromatographic standard e.g. it was added in the sample after the end of the extraction. Analysis of the extracts was performed by RP-HPLC with photodiode array detection. Quantitation was performed in four selected wavelengths and comparative results are provided. The extraction reproducibility was also studied employing cartridge-to-cartridge variations. The method was also applied in the analysis of urine samples of heroin and cocaine users.