Lesson 13 - Solid Phase Extraction I

Solid Phase Extraction (SPE)

A chromatographic technique used to prepare samples by removing interfering substances, utilizing a solid phase and a liquid phase.

Reversed Phase SPE

A type of SPE involving a non-polar modified solid phase and a polar liquid phase, effective for mid- to non-polar analytes.

Normal Phase SPE

A type of SPE that uses a polar stationary phase and a mid-polar to non-polar liquid phase, suitable for mid- to polar analytes.

Ion Exchange SPE

SPE utilized for charged compounds where retention is based on the electrostatic attraction between charged functional groups.

pH role in SPE

The pH of the sample matrix must be adjusted so that both the analyte and stationary phase are charged for effective ion exchange.

Retention Mechanisms in SPE

Include van der Waals forces, hydrogen bonding, dipole-dipole forces, and cation-anion interactions.

Selective Extraction

Choosing an SPE sorbent that binds specific components from a sample, allowing the target compounds or impurities to be retained.

Selective Washing

Retaining target compounds and impurities on SPE packing while washing out impurities with a stronger solution.

Selective Elution

Eluting adsorbed compounds of interest with a solvent that allows strongly retained impurities to remain.

Hydrophobic Interactions

Nonpolar-nonpolar interactions that occur in reversed phase SPE, resulting from attractions between analyte C-H bonds and sorbent functional groups.