Synthesis of magnetic graphene oxide modified with dodecylamine and its application for the determination of seven endocrine-disrupting chemicals in environmental water samples

Abstract

Magnetic graphene oxide (MGO) modified with dodecylamine (DDA) was synthesized in this work. The as-prepared MGO-DDA was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and vibrating sample magnetometer measurements. The material was used as the absorbent in magnetic solid-phase extraction (MSPE) for seven environmental endocrine-disrupting chemicals (EDCs):estrone (E1), β-estradiol (E2), estriol (E3), 17α-ethynylestradiol (EE2), hexoestrol (HEX), androstendione (AND), and bisphenol A (BPA). MSPE combined with HPLC-UV was developed for the determination of EDCs in environmental water samples. The effects of the amount of adsorbent, adsorbing time, and the type and volume of eluents on the recoveries of the EDCs were investigated. Under the optimal conditions, good linear relationships between the UV signals and the EDC concentrations were obtained, with R2 greater than 0.999. The limits of detection for all the EDCs were between 0.10 and 0.23 nmol/L. The MSPE-HPLC-UV method was successfully applied to the analysis of the seven EDCs in environmental water samples such as lake water and sewage water samples. The recoveries of all the EDCs in spiked lake water and sewage water samples were between 73.9% and 114.7%, and the RSDs ranged from 0.7% to 11.8%. Thus, the proposed MSPE-HPLC-UV method is simple, reliable, sensitive, and low-cost.