Optimization of the QuEChERS method for multi-residue analysis of pharmaceuticals and pesticides in aquaculture products

The aim of study was to optimize an QuEChERS extraction procedure for simultaneous determination of organic pollutants in aquaculture products. The QuEChERS extracts were measured using LC-HRMS. The target contaminants include 32 pesticides and 20 pharmaceuticals which have not been regulated for the products in Korea. The method was validated according to CODEX guideline (CAC/GL 71-2009). LOD and LOQ for all analytes ranged from 0.1 to 2 μg/kg and from 0.5 to 5 μg/kg, respectively. Intra-day (n = 5) and inter-day (n = 9) accuracy and precision were evaluated with the guideline. The validated method was applied to aquaculture products (n = 303). As a result, 14 pesticides and 8 pharmaceuticals were quantified. Fluxapyroxad, a fungicide frequently detected in domestic surface waters, was found with relatively higher concentration in 17 out of 23 species. It proves that a hydrophobic inland contaminant can be accumulated in the aquaculture products.