基于碳纳米管的固相萃取-分散液液微萃取测定水中多种痕量环境雌激素

建立了基于碳纳米管的固相萃取-分散液液微萃取/ 上浮溶剂固化-高效液相色谱/荧光法测定水体中痕量雌激素雌三醇(E3)、 双酚A(BPA)、 17α-乙炔基雌二醇(EE2)及17β-雌二醇(E2)的方法. 利用中心复合实验设计分别对固相萃取和分散液液微萃取条件进行了优化, 通过响应曲面法得到的最佳萃取条件为碳纳米管用量30 mg, 水样体积210 mL, 流速2.0 mL/min, 萃取剂(十二醇)体积50 μL, 分散剂(甲醇)体积0.2 mL以及不添加盐. 在优化的实验条件下, E3, BPA, EE2和E2测定的线性范围分别为0.05~100, 0.05~100, 0.05~50和0.05~50 μg/L, 相关系数为0.9993~0.9999, 检出限分别为48.4, 3.3, 8.1和6.0 ng/L. 对不同加标浓度(0.40和4.00 μg/L)的实验室自来水、 排水沟污水及市售矿泉水3种实际水样进行了分析: E3, BPA, EE2和E2的加标回收率依次为107.5%~120.8%, 92.5%~108.3%, 103.5%~121.0%和102.5%~132.5%, 相对偏差分别为2.47%~13.28%, 1.73%~11.94%, 1.72%~8.36%和3.54%~11.95%, 富集因子平均值分别为461, 1075, 2074和949. 实际水样分析结果表明, 本方法可用于不同基质水样中雌激素的测定. 与其它方法相比, 本方法虽然固相萃取时间长及水样量大, 但检出限低、 富集因子高、 操作简便及费用低, 仍可作为一种可普及的水中痕量雌激素检测方法.

Carbon Nanotubes Assisted Solid-phase Extraction Combined with Dispersive Liquid-liquid Microextraction Based on Solidification of Floating Organic Droplet Method for the Determination of Trace Level Environmental Estrogens in Aqueous Solutions

An analytical method,carbon nanotubes assisted solid-phase extraction combined with dispersive liquid-liquid microextration based on solidification of floating organic droplet(SPE/CNT-DLLME/SFO),was developed to determine estriol(E3),bisphenol A(BPA),17α-ethinyl estradiol(EE2) and 17β-estradiol(E2) in aqueous samples.Both solid-phase extraction and dispersive liquid-liquid microextraction were investigated and optimized using central composite design,and the optimized conditions were obtained as follow: carbon nanotubes 30 mg,water sample 210 mL,flow rate of water sample 2.0 mL/min,extractant volume(dodecanol) 50 μL,dispersant(methanol) volume 0.2 mL,and without the addition of salts.Under the selected extraction conditions,linearity range of this established method were in the range of 0.05—100 μg/L for E3 and BPA,0.05—50 μg/L for EE2 and E2,and the correlation coefficients(R2) were 0.9993—0.9999.The limits of detection were ranged from 3.3 to 48.4 ng/L.The recoveries of estrogens under different spiked levels(0.40 and 4.00 μg/L) for E3,BPA,EE2 and E2 were 107.5%—120.8%,92.5%—108.3%,103.5%—121.0% and 102.5%—132.5%,and the relative deviations were 2.47%—13.28%,1.73%—11.94%,1.72%—8.36% and 3.54%—11.95%,respectively.The average of enrichment factor for E3,BPA,EE2 and E2 were 461,1075,2074 and 949,respectively.Additionally,the established method could be applied to the analysis of estrogenic hormones in water samples collected from tap water,barrel-drain and commercial mineral water.Though it needs long time for solid phase extraction and large volume sample,compared with some other methods,the present method has many advantages such as low limit of detection which is on the same level as GC/MS(gas chromatography/mass spectrometry),high enrichment factor,simplicity of operation,low cost,and therefore it is an alternative method that could be widely used for the analysis of trace level of environmental estrogens.