Horizon Technology, Inc.

What is SPE?

Solid Phase Extraction is an extraction process whereby an aqueous sample is filtered through a bed of sorbent particles. The sorbent particles are usually in the form of a disk or a cartridge. Analytes of interest are removed from the aqueous sample, and concentrated onto the sorbent. Once concentrated, the analytes are removed from the sorbent by a series of eluting solvent rinses.

Solid Phase Extraction methods offer significant advantages over traditional Liquid-Liquid Extraction (LLE) techniques.

SPE uses less solvent than a typical LLE procedurE

SPE is faster; only 20-30 min for a 1-liter sampl

SPE costs considerably less than LLE

SPE provides comparable / better recoveries than LLE

EPA Methods are constantly being developed for SPE

Comparison of LLE and SPE Disk Methods
LLE	SPE Disk
Uses 200 to 500 mL of solvent	Uses 20 to 30 mL of solvent
Shaking/continuous process	Filtration process
Forms emulsions and surfactants	No emulsions formed
Limited selectivity	Wide selectivity (absorbant)
Requires solvent removal	Optional
Two hours per sample	20 minutes per sample