A Simple and Robust Protocol for fast RP-HPLC Determination of Salicylates in Foods

In this methodological report, we present a simple, versatile, and reliable procedure for quantitative determination of free and conjugated forms of salicylic acid (SA) in various food products using reversed phase high-performance liquid chromatography (RP-HPLC) with fluorescence detection. The presented sample preparation protocol is considerably simplified in comparison to procedures applied previously and is based on three simple and fast extraction steps providing a supreme tool for large-scale routine assays. The limits of detection were approximately 0.021 μg g−1 of dried weight for spices, lyophilized fruits, or vegetables, and 0.001 μg ml−1 for beverages. The recoveries of the spiked SA were in the range of 87.6 to 96.6 % for all studied products. Applicability of the method was verified by the analysis of salicylate content in a wide range of products including spices (curry, oregano, red pepper), beverages (beer, brewed tea, milk, wine), lyophilized fruits (apricot, strawberry, watermelon), and vegetables (cucumber, tomato).