Analysis of iodinated amino acids by microemulsion electrokinetic chromatography using aliphatic amine as a cosurfactant

Abstract

A novel microemulsion electrokinetic chromatography (MEEKC) was established for the separation and determination of iodinated amino acids using n-butylamine as a novel cosurfactant. By optimizing the type of oil phase, the type and concentration of surfactant, the concentration of cosurfactant and the type and concentration of buffer in the microemulsion system, the optimal conditions for the separation of organic iodines were determined to be 0.5% ethyl acetate, 0.6% SDS, 1.2% n-butylamine and 10 mM sodium borate. The efficient and rapid separation of the five analytes (3-iodo-L-tyrosine (MIT), 3, 5-Diiodo-L-tyrosine (DIT), 3, 5-Diiodo-L-thyronine (T2), 3, 3′, 5-Triiodo-L-thyronine (T3) and L-Thyroxine (T4)) was achieved under the optimal conditions. The reliability of the method was verified by measuring the precision, LOD, LOQ and recovery. The practicality of the MEEKC method was demonstrated by applying it to the determination of two iodotyrosines, MIT and DIT, in kelp. The analytical method established in this experiment will provide a reference for the study of iodotyrosines in other natural plants and food.