|HAN, LIJUN - China Agricultural University|
Submitted to: Journal of Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/2020
Publication Date: 3/10/2020
Citation: Han, L., Sapozhnikova, Y.V. 2020. Semi-automated high-throughput method for residual analysis of 302 pesticides and environmental contaminants in catfish by fast low-pressure GC-MS/MS and UHPLC-MS/MS. Journal of Food Chemistry. https://doi.org/10.1016/j.foodchem.2020.126592.
Interpretive Summary: Catfish is one of the most consumed freshwater fish in the USA, valued for its nutritional benefits. A simple, fast and efficient analytical method was developed and validated for the residual analysis of 302 contaminants in catfish muscle. The contaminant list included diverse pesticides and environmental contaminants. The method was successfully validated at and below US tolerance/levels of concerns for the selected contaminants. The validated method was applied to the analysis of fish from the market, showing its applicability to other fish besides catfish. Six pesticides and metabolites plus one polyaromatic hydrocarbon were measured in catfish, tilapia and salmon at concentrations below the US regulatory levels. The method is expected to be implemented by USDA FSIS for routine monitoring of contaminants in meats and poultry in the US National Residue Program.
Technical Abstract: A fast, fit-for-purpose, high-throughput semi-automated method was developed and validated for the analysis of 302 targeted contaminants in catfish muscle. Targeted contaminants included pesticides and metabolites with US regulatory levels, plus other lipophilic pesticides and environmental contaminants: PAHs, PCBs, PBDEs and other flame retardants. The sample preparation was based on QuEChERS extraction with acetonitrile and simultaneous salting-out. The extract was split and analyzed by UHPLC-MS/MS for 128 analytes after filtering and by low pressure (LP)GC-MS/MS for 219 analytes after an automated robotic micro-SPE cleanup. Both LPGC- and UHPLC-MS/MS analyses were fast (10 min each), providing wide qualitative and quantitative monitoring scope, with 45 contaminants analyzed by both techniques. In the automated robotic sample cleanup, two different SPE sorbent mixes were evaluated for recoveries of the targeted analytes and removal efficiency of co-extracted matrix. The final method was validated at four spiking levels (5, 10, 20 and 40 ng/g) for the majority of analytes with 10 replicates per level. Satisfactory recoveries (70-120%) and RSDs (=20%) were achieved for 80% of the analytes with normalization to isotopically-labeled internal standards. Fit-for-purpose LOQs = 5 ng/g and matrix effects within ±20% were achieved for the majority of analytes. The method was further validated with NIST SRMs 1946 and 1947 and applied for the analysis of 22 market fish samples. Six pesticides and one PAH were found in the market fish samples, all below US regulatory levels.