Análise de ácidos graxos por eletroforese capilar utilizando detecção condutométrica sem contato

Abstract

Recebido em 7/10/02; aceito em 27/3/03 ANALYSIS OF FATTY ACIDS BY CAPILLARY ELECTROPHORESIS WITH CONTACTLESS CONDUCTIVITY DETECTION. This article describes a novel approach to the separation of fatty acids ranging from 8 to 20 carbons using capillary electrophoresis with contactless conductivity detection. Complete separation of nine linear chain fatty acids (from C8:0 to C20:0) was achieved in 15 min under normal polarity operation. Limits of detection ranged from 35 to 319 µmol L-1 for C20:0 to C8:0, respectively. The optimized running electrolyte composition was 5.0 mmol L-1 phosphate buffer at pH 7, 4.0 mmol L-1 dimethyl-β-cyclodextrin, 2.0 mmol L-1 trimethyl-β-cyclodextrin, acetonitrile 50% (v/v), and methanol 20% (v/v). The applicability of the separation system was demonstrated by the analysis of coconut vegetable oil.