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 0.5min. The BGE is composed of 10mmolL−1 perchloric acid and 40mmolL−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 (250mgkg−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. Display omitted •A sub-minute CZE method was developed for the determination of nitrate and nitrite.•The CZE method was applied in the analysis of baby foods.•Sample preparation step was simple and effective to extract the analytes.•Analytical validation was performed according to the Eurachem guidelines.•The CZE method showed good analytical performance to the analysis of baby foods.