Analysis of five bisphenol compounds in sewage sludge by dispersive solid-phase extraction with magnetic montmorillonite

A method for the quantitative determination of bisphenol S, bisphenol F, bisphenol A, bisphenol B, and bisphenol AF in sewage sludge was developed and validated. The target compounds were extracted by ultrasound assisted with MeOH-water mixture (1:1, v/v) and clean-up by dispersive solid-phase extraction with magnetic montmorillonite. Analytical determination was carried out high-performance liquid chromatography. After been optimized, the method showed method detection limit (S/N = 3) ranged from 5.1 to 8.6 ng/g. The developed method had acceptable relative recoveries (84.3-98.2%) and precision (RSDs: 2.6-5.6%). The matrix effect significantly decreased after clean-up by the prepared material. The results demonstrated that the optimized method was a simple and reliable analytical technique for analyzing bisphenols in the sludge samples. Finally, the optimized method was applied to the quantitation of five BPs in sewage sludge samples collected from different wastewater treatment plants in Chongqing, China, and various concentrations of bisphenols were found in the sludge samples, indicating the wide-spread presence of BPs in sludge.