分散液-液微萃取过程中内分泌干扰物在离子液体/水相体系中的分配行为

Partitioning of Endocrine Disrupting Compounds between Ionic Liquid and Aqueous Phase in the Dispersive Liquid-Liquid Microextraction Process

以离子液体([C6MIM]PF6)作萃取剂、甲醇为分散剂,对水样中的内分泌干扰物(雌三醇(E3)、双酚A(BPA)、17α-乙炔基雌二醇(EE2)、雌二醇(E2)、雌酮(E1))进行分散液-液微萃取,比较了内分泌干扰物在[C6MIM]PF6/水相和传统有机萃取剂/水相的分配系数,利用NRTL方程对内分泌干扰物在萃取相/水相中平衡分配的摩尔分数进行了关联,并对[C6MIM]PF6萃取内分泌干扰物的过程进行了机理分析.结果表明,在所考察的浓度范围内,内分泌干扰物在[C6MIM]PF6/水相中的分配规律为DEE2>DBPA>DE1>DE2>DE3,内分泌干扰物在[C6MIM]PF6/水相中的分配系数均显著高于其在传统有机萃取剂/水相中的分配系数,NRTL方程验证了内分泌干扰物与萃取剂及溶剂分子间相互作用能的大小.

Extraction of the endocrine disrupting compounds （EDCs, such as estriol, bisphenol A, 17α-ethynylestradiol, estradiol and estrone） in water was investigated based on dispersive liquid-liquid microextraction procedure with ionic liquid （[ C6MIM ] PF6 ） as extraction solvent and methanol as dispersive solvent. The distribution coefficients of EDCs between ionic liquid and aqueous phase were compared with those of EDCs between conventional organic solvent and aqueous phase, and the equilibrium molar fractions of EDCs in the system of [ C6MIM ] PF6-water were correlated with the help of the well-known NRTL equation, and finally, the mechanism of extraction reaction between [ C6MIM] PF6 and EDCs was discussed as well. The experimental results show that the highest distribution coefficients of EDCs between [ C6MIM ] PF6 and aqueous phase were DEE2, followed by DBPA ,DE1 ,DE2 and DE3 in the studied concentration range, and the distribution coefficients of EDCs in the system of [ C6MIM ] PF6/water was much higher than that in the system of conventional organic solvent/water, and the molecular interactions among EDCs-extraction solvent-water were validated by NRTL equation.