Screening and determination of aliphatic organic acids in commercial Brazilian sugarcane spirits employing a new method involving capillary electrophoresis and a semi-permanent adsorbed polymer coating

A simple method for the screening and determination of short chain aliphatic carboxylic acids in Brazilian sugarcane spirits by indirect capillary zone electrophoresis was developed and validated according to Eurachem guidelines. The separations were performed in a coated capillary (L-tot 73 cm X L-det 64.5 cm) with 2-hydroxy-propyltrimethyl-ammonium chloride chitosan. The background electrolyte was optimized using Pealcmaster (R) software and was composed of 21 mmol L-1 beta-alanine and 10 mmol L-1 3,5 dinitrobenzoic acid, at pH 3.6, with an applied voltage of -30 kV. The method was validated for formic, lactic and acetic acids. Linearity was demonstrated and significant matrix effects were not observed at between 2.8 and 144 mg L-1. The recovery (means of 89.6-117.9%) was evaluated, and ANOVA was carried out to determine the RSD values for the repeatability (2.63-835%) and reproducibility (1.92-6.62%). The LOD and LOQ ranged from 0.69 to 2.70 and 2.76 to 8.11 mg L-1, respectively. The concentrations detected in the samples were 0.19-106.43 mg per 100g. (c) 2014 Elsevier Ltd. All rights reserved.