Optimization of fluorimetry for determination phthalate esters in snails by response surface methodology

The optimum conditions for determining total phthalate esters (PAEs) in snail samples by fluorimetry were established by using response surface methodology (RSM) . The optimal levels were as follows:the concentration of NaOH was 4. 61mol/L, the pH of Na2HPO4-NaH2PO4 buffer solution was 7.09, and the volume of EDTA-Fe (Ⅱ) and H2O2 was 0.55mL, 1.63mL respectively. Snail samples were ultrasonic extracted by hexane and dichloromethane 1∶1 mixed solution with 1∶1.6 (g/mL) ratio of solid-to-liquid at first, and then were performed under the optimized conditions as mentioned above. The results showed that the relative standard deviation of the method were 1.73%～6.56%, the average recoveries ranged from 93.80% to 106.11%, and the PAEs of snail was about 26.64～44. 89mg/kg.