SOLID-PHASE MICROEXTRACTION IN BIOANALYSIS.
Emile Koster
Spark Holland BV, P.O.Box 288, 7800 AJ Emmen, The Netherlands

One relatively new sample pretreatment approach in bioanalysis is solid-phase microextraction (SPME). In SPME analytes are passively transferred from a sample to an immobilized, supported liquid or solid. Extraction efficiency is determined by the passive partition of analytes between the sample matrix and the extraction phase. The evolution of the SPME in combination gas chromatography finds its origin in environmental analysis. About five years ago, hardly any research was performed on the applicability of SPME as a new sample pretreatment method for the determination of drugs in biological samples. As SPME proved to be easy-to-handle, the method also seemed to be very useful for on-site sampling at the bed of the patient in the future. 
The objective of the research described in this presentation is to demonstrate the potential of SPME in bioanalysis. For this briefly some background information about direct-immersion SPME is given. Systematic optimization of SPME is depicted in order to demonstrate the effects of sampling conditions, analyte properties and coating characteristics on the extraction performance. Furthermore, special methodologies are shown to reduce sample-handling time and to improve the sensitivity and selectivity of this extraction technique. Examples are shown to demonstrate that SPME can be used to determine drugs in biological samples.