Going Green In Food Analysis: A Rapid And Accurate Method For The Determination Of Sorbic Acid And Benzoic Acid In Foods By Capillary Ion Chromatography With Conductivity Detection

Abstract An innovative analytical method for the simultaneous determination of two food preservatives, sorbic acid (SA) and benzoic acid (BA), by capillary ion chromatography with conductivity detection (CIC-CD), was developed. After optimization of a simple bain-marie alkaline extraction/purification procedure and chromatographic conditions, the method was validated with excellent results in terms of linearity (R2 > 0.999), recovery values (ranging from 90.2% to 105.8%), limit of detection and quantification (1.6 and 4.1 mg kg-1 and 4.9 and 12.6 mg kg-1 for SA and BA, respectively) and precision (CV% lower than 3.9). The method was applied to all food and beverage types in which the additives may be added, according to European regulations, successfully. CIC-CD proved to be flexible, highly sensitive and selective, accurate and robust. Finally, embracing the main principles of Green Analytical Chemistry and the challenge of greening laboratory practices, the proposed method may be considered environmentally friendly, sustainable and “reagent-free”.