An alternative method for rapid quantitative analysis of majority cis–trans fatty acids by CZE

Abstract

An alternative methodology for simultaneous analysis of majority cis–trans fatty acids such as stearic (C18:0), elaidic (C18:1t), oleic (C18:1c), palmitic (C16:0), linoleic (C18:2cc) and linolenic (C18:3ccc) by capillary zone electrophoresis (CZE) under indirect detection was proposed in this work. The CZE methodology was optimized through the 23 central composite design (23 CCD) with three replicates in central point, having as factors Brij 35, acetonitrile and 1-octanol. The background electrolyte (BGE) for the optimum separation condition consisted of: 15.0mmolL−1 of NaH2PO4/Na2HPO4 buffer at pH≈6.86, 4.0mmolL−1 of SDBS, 8.3mmolL−1 of Brij 35 and 45% v/v of ACN, and 2.1% of 1-octanol was achieved by analyzing of the 23 CCD together with the principal component analysis (PCA). The FA quantification was performed through response factor (Rf) approach, which provided high analytical throughput for the real samples analysis. The CZE method optimized was successfully applied to the analysis of FA in samples of olive oil, soy oil, hydrogenated vegetable fat, butter, margarine and filled cookie. The results obtained were compared with AOCS GC official method (Ce 1j-07) through paired sample t test and no significant difference was found within 95% confidence interval.