Development and validation of a sub-minute capillary zone electrophoresis method for determination of nitrate and nitrite in baby foods

Abstract

This paper proposes an innovative sub-minute capillary zone electrophoresis method and a simple sample preparation procedure for simultaneous nitrate and nitrite determination. The novelty of the method is the simplicity of execution and the capacity to separate the analytes in less than 0.5 min. The BGE is composed of 10 mmol L(-1) perchloric acid and 40 mmol L(-1) β-alanine at pH 3.96. Thiocyanate was used as an internal standard. The method was validated following the Eurachem guidelines and applied to the analysis of 14 baby food samples. Of these samples, one had nitrate levels above that permitted by Brazilian legislation (250 mg kg(-1)) and for all samples the nitrite concentrations were under the limit of quantification. The good analytical performance verified for this method indicates that it is suitable for implementation in food laboratories for the routine determination of nitrate and nitrite as an alternative to the official method provided by the AOAC.