固相萃取-分散液液微萃取-柱前衍生法测定水样中痕量雌激素

建立了碳纳米管的固相萃取-分散液液微萃取-柱前荧光衍生化(SPE-DLLME-PFD)测定水体中痕量雌三醇(E3)、双酚A(BPA)、17α-乙炔基雌二醇(EE2)及17β-雌二醇(E2)的高效液相色谱方法.采用中心复合设计和响应曲面法分析并优化SPE、DLLME及PLD条件,最佳条件为210 mL水样以2.0 mL/min的流速过固相萃取柱(碳纳米管量30 mg),甲醇洗脱,氮气浓缩并定容至0.6 mL(分散剂),将100 μL C6MIMPF6]与分散剂的混合液注入到NaCl含量为25％的2.0 mL去离子水中,离心,移取20 μL下层有机相于样品瓶中,与4.0 mg衍生剂混合,在40℃水浴中衍生25 min;用0.1mL甲醇溶解过量的衍生剂颗粒,取20 μL进样分析.在优化条件下.4种雌激素的线性范围为0.05～5.00 μg/L,相关系数R2=0.9966～0.9999;,检出限介于0.13～6.33 ng/L(S/N=3)之间.不同加标浓度条件下,雌激素的加标回收率在83.1％～122.4％范围内(RSD=1.7％～9.6％).在实际水样中E3和BPA检出率较高.与其它方法相比,本方法虽然萃取时间长、水样量大、步骤多,但具有检出限低、操作简便、环境友好等优点.

Combination of Solid Phase Extraction-Dispersive Liquid Liquid Microextraction and Pre-column Derivatization Method for Determination of Trace Level Estrogens in Water Sample

A method,carbon nanotubes assisted solid phase extraction combined with dispersive liquid-liquid microextration and pre-column derivatization(SPE-DLLME-PFD),was developed for the determination of estriol(E3),bisphenol A(BPA),17α-ethinyl estradiol(EE2) and 17β-estradiol(E2) in water samples.SPE,DLLME and PFD process was studied and optimized using central composite design and response surface plot.The optimized conditions were as follows: target estrogens were adsorbed from 210 mL aqueous samples into 30 mg carbon nanotubes at 2.0 mL/min;methanol used as elution solution was concentrated to a volume of 0.6 mL,which was mixed with 100 μL of C6MIM and the blend was added to 2.0 mL of deionized water(25.0% NaCl,g/L).After centrifugation,20 μL of the settled organic phase was mixed with 4.0 mg derivating agent,and the reaction was occurred for 25 min at 40 ℃.Finally,0.1 mL of methanol was used to dissolve the particles of derivating agent,and 20 μL of that sample was analyzed.Under the chosen conditions,linearity range of the established method was 0.05-5.00 μg/L with R2 of 0.9966-0.9999 for the target estrogens,and the LODs were in the range of 0.13-6.33 ng/L.The recoveries of estrogens under different spiked levels for four estrogens were 83.13%-122.39%(RSD was 1.7%-9.6%).E3 and BPA could be detected in the most of the real water samples.Compared with some other methods,the present method needed long extraction time,large volume sample and multi-steps,while it also had many advantages such as low LOD,simplicity of operation,and environmental friendly.