Determination of three fluorescent whitening agents (FWAs) and their migration research in food contact plastic packaging containers and food simulants by UPLC-MS/MS method

Abstract

In order to determine three fluorescent whitening agents (FWAs), including FWA184, FWA368 and FWA 393 in migration solutions of food contact plastic packaging containers, a sensitive UPLC-MS/MS method was developed based on the migration tests using food simulants. Under the optimized conditions, the calibration curves were linear over the selected concentration ranges of 0.03–200 μg L⁻¹ for all three analytes, with calculated coefficients of determination (R²) greater than 0.999. The limits of detection (LODs) and the limits of quantitation (LOQs) of the method were 0.01–0.03 μg L⁻¹ and 0.03–0.09 μg L⁻¹, respectively. Recoveries were calculated at three levels of concentration spiked in a negative sample. The values were found between 96.1% and 111.4% with relative standard deviation (RSD) values of 3.0–6.1% for intra-day precision (n = 6) and 2.6–6.4% for inter-day precision (n = 5). The developed method was applied to study the migration trend of target analytes in different migration temperatures and times, and corresponding migration equations with correlation coefficients more than 0.991 were obtained. Finally, the method was successfully applied to analyze migration solutions of twenty samples and FWA184 was detected only in samples with a concentration 0.57 μg L⁻¹ at 25 °C and 0.21 μg L⁻¹ at 5 °C, respectively.