原位生成TiO_2·nH_2O-分散微固相萃取-高效液相色谱法测定环境水样中4种酚类污染物

Determination of four phenolic endocrine disruptors in environmental water samples by in-situ generated TiO_2·nH_2O-dispersive micro solid phase extraction and high performance liquid chromatography

通过直接向样品溶液喷入钛酸四丁酯,由其水解产生含水二氧化钛(TiO_2·nH_2O)作为吸附剂,建立了原位分散微固相萃取样品前处理新技术,并结合高效液相色谱法测定了环境水样中4种酚类内分泌干扰物(双酚A、三氯生、辛基酚和壬基酚)。透射电镜和红外表征结果显示,原位水解产生的吸附剂颗粒直径在20～80 nm之间且表面存在大量羟基。实验优化了TBOT用量,萃取时间,离子强度和洗脱液类型等萃取条件。在最优条件下,4种待测物的检出限为0. 18～2. 16μg/L,定量限为0. 60～7. 21μg/L,富集倍数为14. 7～169. 4。方法具有良好的线性和精密度,已应用于实际湖水试样中4种目标物的检测,加标回收率在95. 0%～112. 5%之间,相对标准偏差在0. 4%～7. 1%之间。

In this study, a rapid and sensitive dispersive micro solid phase extraction using in-situ generated hydrous titanium dioxide （TiO2 · nH2O） as sorbents was developed for the determination of four phenolic endocrine disruptors （bisphenol A, triclosan, octylphenol and nonyphenol ） in environmental water for the first time. The in-situ generation of hydrous TiO2 was realized by simply injecting of tetrabutyl titanate （TBOT） into the aqueous sample. A huge contact area has been obtained by this way, thereby it could shorten extraction time and enhance extraction efficiency. After extraction, the concentrated analytes in the precipitated phase were separated from sample solution by centrifugation and appropriate solvent was used to release them. Experimental factors such as the amount of TBOT, extraction time, ion strength, eluent, elution volume and elution time were investigated to achieve the best performance. The results showed that this method provided good linearities （ R2 ≥ 0. 9957 ） and precisions （RSD ≤ 6. 1% ）. The limits of detection were in the range of 0. 18 -2. 16 μg/L, and the limits of quantitation were in the range of 1.42 - 10. 19 μg/L. The recoveries from the spiked environment water samples were from 95.0% and 112. 5% , with RSD less than 7. 1%.