Introduction to solid-phase microextraction (SPME)

Solid-phase microextraction or SPME is a unique solventless sample prep technique. SPME uses a polymer-coated fiber to concentrate volatile and semi-volatile organics in one extraction step. SPME requires no solvents or complicated extraction apparatus.

The SPME fiber is attached to a plunger inside a protective needle, which is attached to a holder that looks like a micro liter syringe. The plunger inside of the holder moves the SPME fiber into and out of a protective needle for extraction of organics from a sample matrix. The organics are adsorbed onto the liquid coating on the fiber for a predetermined amount of time.

The SPME fiber is retracted into the protective needle and injected into the heated injector of the gas chromatograph. The organics are then thermally transferred onto the chromatographic column for separation and measurement. Afterwards, the SPME fiber is retracted into the needle and removed from the injection port for subsequent sample analysis.