Spectrophotometric Determination of Bisphenol A with Color-Fading Reaction of Fast Green

In sulfuric acid solution, Fenton reaction was used to produce hydroxyl radical to discolor fast green. But bisphenol A could inhibit the oxidation of hydroxyl radical on fast green. Based on this fact, spectrophotometric method for determination of bisphenol A by color-fading of fast green was proposed. The optimized conditions found were as follows: ① amount of 0.005 mol·L-1 H2SO4 solution: 200 μL; ② amount of 0.005 mol·L-1 FeSO4 solution: 75 μL; ③ amount of 80 mg·L-1 fast green solution: 300 μL; ④ amount of 20 mmol·L-1 H2O2 solution: 60 μL; ⑤ time of reaction: 10 min;⑥temperature of reaction: 50 ℃. Linear relationship between values of absorbance and mass concentration of bisphenol A was obtained in the range of 1.6×10-5-2.0×10-4g·L-1, with detection limit (3σ) of 6.3×10-6g·L-1. Values of recovery found by standard addition method were in the range of 94.2%-104%, and values of RSD′s (n=5) in the range of 2.9%-3.2%.