Sample Preparation and Handling in Bioanalytical Applications

Most biological samples analysed by GC/MS or LC/MS need sample preparation, depending on the matrix content and concentration of the analyte. In cHnical and forensic toxicology, for example, body fluids such as blood/serum and urine have to be analysed as weU as tissue samples (organs, muscle), stomach contents, and hair [45]. In environmental toxicology, sewage sludge, sediments, waste water, or plant material contain only traces of the analytes of interest, thus concentration and clean-up steps are necessary prior to analysis. 

For the determination of drugs in plasma, extraction and concentration are also necessary in most cases. Matrix effects can influence the chromatographic separation in GC- or LC/MS, and also the ionisation process in ESI mass spectrometry [45, 46]. 

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