Simultaneous Determination of 14 Organophosphate Ester Flame Retardants in Aquatic Products by UHPLC-MS/MS: Method Development, Validation, and Application

In this study, a robust UHPLC-MS/MS method was developed for simultaneously determining 14 organophosphate ester flame retardants (OPEs) in aquatic products. Sample extraction and clean-up procedures were optimized, and matrix effects were corrected using matrix-matched calibration with internal standards. The validated method exhibited good linearity (R2 > 0.991), low detection limits (0.015–0.180 ng g−1 wet weight, ww), low quantification limits (0.050–0.600 ng g−1 ww), high recoveries of 70.6–119%, and good precision (relative standard deviations < 15%). Application to fish, sea cucumber, shrimp, and mussel samples confirmed the method’s high sensitivity and accuracy. Analysis of 200 aquatic product samples revealed widespread yet species- and compound-specific OPE contamination, with total concentrations up to 1429.4 ng g−1 ww. Chlorinated OPEs predominated, particularly tris(2-chloroethyl) phosphate (TCEP) and tris(1-chloro-2-propyl) phosphate (TCIPP). TMCP, TOCP, and TMPP were reported as a combined concentration (ΣTCP) in real samples, expressed as TMCP equivalents. These findings suggest that further investigations are required to assess OPE distributions, accumulation patterns, and dietary exposure risks in aquatic products.