Kiinteäfaasimikroeristys

Kiinteäfaasimikroeristys, often abbreviated as SPME, is a sample preparation technique used in analytical chemistry. It involves the extraction of analytes from a sample matrix directly into a solid stationary phase. This stationary phase is typically coated onto a fused silica fiber, which is then mounted on a needle. The fiber is exposed to the sample, either in the headspace above a liquid or solid sample, or by direct immersion into a liquid. Analytes from the sample partition from the sample matrix into the stationary phase coating on the fiber.

After a suitable extraction time, the fiber is retracted and can be directly introduced into an analytical instrument, most commonly a gas chromatograph (GC) or liquid chromatograph (LC). The adsorbed analytes are then thermally desorbed from the fiber directly into the GC injection port or eluted from the fiber with a suitable solvent for LC injection. SPME offers several advantages, including the elimination of traditional solvent-based extraction steps, reduced sample consumption, and potential for automation. It is a versatile technique applicable to a wide range of matrices, including water, air, soil, and biological samples, and is used for the analysis of various compounds such as volatile organic compounds (VOCs), pesticides, and pharmaceuticals. The choice of stationary phase coating on the fiber is crucial and is selected based on the chemical properties of the analytes of interest.