Determination and Adult Dietary Exposure Evaluation of Bisphenol A and Bisphenol S in Common Foods

Considering that bisphenol A (BPA) and bisphenol S (BPS) had estrogen effects and more contact with the population, liquid chromatography-tandem mass spectrometry was used to determine 2 phenolic compounds in 408 common foods (including water, beverages, rice, wheat, seashells, fish, livestock and poultry meat, vegetable, canned grain, canned fish, canned livestock and poultry meat, edible oil, egg and so on), and the international estimated daily intake (IEDI) was used to assess the value of adult dietary exposure. Water samples were determined as follows:20.0 mL of sample together with 3 ng of ¹³C₁₂-BPS, 10 ng of BPA-d₄ and 0.2 mL of ammonia water were mixed evenly, and passed through a activated MAX solid phase extraction column. The column was eluted with 5 mL of formic acid-acetonitrile-water mixed solution at volume ratio of 2:88:10 after rinsing. The eluate was blown to dryness by nitrogen at 45℃, and the residue was redissolved with 1.0 mL of 20% (volume fration) acetonitrile solution, ultrasonicated for 30 s, swirled for 30 s, and passed through a 0.22 μm filter membrane. The filtrate was analyzed by liquid chromatography-tandem mass spectrometer. Beverage samples were determined as follows:10.0 g of sample together with 3 ng of ¹³C₁₂-BPS, 10 ng of BPA-d₄ and 10 mL of acetonitrile solution containing 2% (volume fraction) formic acid (acidified acetonitrile) were vortexed for 10 min, and 4.0 g of anhydrous magnesium sulfate and 1.0 g of sodium chloride were added for vortex for 3 min and centrifugation for 5 min. An aliquot (5 mL) of the upper acetonitrile phase was taken, and mixed with 15 mL of 2% (volume fraction) ammonia aqueous solution, and the mixed solution was purified with reference to the water sample. Other samples were determined as follows:2.0 g of other samples together with 3 ng of ¹³C₁₂-BPS, 10 ng of BPA-d₄, 10 mL of water, and 10 mL acidified acetonitrile were mixed, and the subsequent processing steps referred to beverage samples. As found by the results, the linear ranges for the standard curves of BPA and BPS were 0.1-400.0 μg·L^-1 and 0.03-120.0 μg·L^-1, with detection limits (3S/N) of BPA and BPS in the ranges of 0.015-1.0 μg·kg^-1 and 0.005 0-0.20 μg·kg^-1, respectively. Test for recovery was conducted by standard addition method, and recoveries of BPA and BPS were in the ranges of 86.0%-116% and 87.0%-112%, with RSDs (n=6) of the determined values in the same range of 1.2%-10%. The proposed method was applied to the analysis of 408 actual samples, and the total detection rates of BPA and BPS were 66.4% and 29.6%, with detection amounts in the ranges of 0.02-148.0 μg·kg^-1 and 0.007-104.0 μg·kg^-1, and the detection rate and amount of BPA in metal canned foods were relatively high. Average IEDI exposure value for total intake of BPA was 48.7 ng·kg^-1·d^-1, significantly lower than the tolerable daily intake (4 μg·kg^-1·d^-1) proposed by the European Food Safety Agency, but that of BPS was higher than the survey value in previous literature. In overall, the risk of current dietary exposure level in adults was still low, but relevant monitoring and population health management still need to be strengthened.