Solid-phase extraction for the reversed-phase high-performance liquid chromatographic determination of iodoamino acids

Abstract

We studied solid-phase extraction (SPE) procedures using three SPE columns (OASIS HLB, MCX and MAX^®) for the determination of iodoamino acids (iodohistidines, iodotyrosines and iodothyronines) by high-performance liquid chromatography (HPLC). Iodoamino acids could be retained on the SPE columns by hydrophobic, cation-exchange and/or anion-exchange interactions. Firstly, the effect of the sample pH on the retention was investigated. Secondly, the elution of iodoamino acids retained on each SPE column was investigated. The recoveries of iodoamino acids were evaluated using different compositions of the eluent. Good recovery (>90%) could be obtained under the optimum SPE conditions.