Determination of Polyamines by Capillary Electrophoresis Using Salicylaldehyde-5-Sulfonate as a Derivatizing Reagent.

Abstract

Here we describe a protocol for the determination of polyamines using capillary electrophoresis with ultraviolet absorbance detection. Aliphatic polyamines were derivatized with salicylaldehyde-5-sulfonate (SAS) which formed Schiff base with amino groups, resulting in anionic derivatives. The derivatization of polyamines, including putrescine (PUT), cadaverine (CAD), spermidine (SPD), and spermine (SPM), was conducted in 10mM HEPES buffer with pH7.8 containing 5mM SAS in a mixed solvent of water and ethanol. The SAS derivatives were separated using a background electrolyte composed of 10mM phosphate buffer with pH7.8. Calibration curves were linear over a concentration range of 20-200μM for CAD, PUT, SPD, and SPM, and the limits of detection (LOD) were several μM for all polyamines. Furthermore, solid phase extraction was coupled with the CE method to improve the LOD to sub-μM levels, and the calibration curves were linear over a concentration range of 1-20μM for CAD, PUT, and SPD.