基于金属有机骨架多孔碳材料的分散固相萃取-超高效液相色谱-串联质谱法测定水中4种酚类内分泌干扰物

Determination of four phenolic endocrine-disrupting chemicals in water by dispersive solid-phase extraction-ultra performance liquid chromatography-tandem mass spectrometry based on metal-organic skeleton porous carbon materials

酚类内分泌干扰物是一种干扰内分泌系统的外源性物质,其进入生物体后会干扰细胞的正常功能,引起生殖发育毒性,因此亟需开发一种快速、灵敏的分析方法,用于环境水体中酚类内分泌干扰物的检测。本研究采用溶剂热法合成了一种由金属有机骨架衍生的多孔碳材料(UiO-66-C),并将其作为萃取吸附剂来富集水中的4种酚类内分泌干扰物(双酚A、4-叔辛基苯酚、4-壬基酚、壬基酚)。建立了一种分散固相萃取(DSPE)结合超高效液相色谱-串联质谱(UPLC-MS/MS)测定水中酚类内分泌干扰物的分析方法。通过扫描电子显微镜、X射线衍射及傅里叶变换红外光谱等测试方法对UiO-66-C进行表征,证明了该材料的成功制备。对DSPE条件进行优化,包括UiO-66-C用量、水样pH、吸附时间、洗脱液种类及体积、洗脱时间和离子强度。在最佳实验条件下,4种酚类内分泌干扰物在0.5~100μg/L范围内线性关系良好,方法检出限和定量限分别为0.01~0.13μg/L和0.03~0.42μg/L,日内和日间精密度分别为1.5%~10.6%和6.1%~13.2%。将该方法应用于自来水和地表水的检测,4种酚类内分泌干扰物的加标回收率为77.1%~116.6%;在自来水样品中未检测到4种酚类内分泌干扰物,而在地表水中检测到微量的4-壬基酚和壬基酚,检出水平分别为1.38μg/L和0.26μg/L。该方法具有良好的准确度和精密度,为环境水体中酚类内分泌干扰物的检测提供了一种快速、高效、灵敏的新途径。

Phenolic endocrine-disrupting chemicals(EDCs)are exogenous substances that interfere with the endocrine system and disrupt normal cell functions upon entering a living organism,leading to reproductive and developmental toxicity.Therefore,the development of a rapid and efficient analytical method for detecting phenolic EDCs in environmental waters is crucial.Owing to the low concentration of phenolic EDCs in environmental water,appropriate sample pretreatment methods are necessary to remove interferences caused by the sample matrix and enrich the target analytes before instrumental analysis.Dispersive solid-phase extraction(DSPE)has gained considerable attention as a simple and rapid sample pretreatment method for environmental-sample analysis.In this method,an adsorbent material is uniformly dispersed in a sample solution and the target analytes are extracted through processes such as vortexing.Compared with traditional solid-phase extraction(SPE),DSPE increases the contact area between the adsorbent and sample solution,reduces the required amounts of adsorbent and organic solvents,and improves the extraction efficiency.The adsorbent material plays a critical role in DSPE because it determines the extraction efficiency of the method.Metal-organic frameworks(MOFs)are porous framework materials composed of metal clusters and multifunctional organic ligands.They possess many excellent properties such as tunable pore sizes,large surface areas,and good thermal and chemical stability,rendering them ideal adsorbent materials for sample pretreatment.MOF-derived porous carbon materials obtained through high-temperature carbonization not only increase the density of MOF materials for better separation but also retain the advantages of a large surface area,highly ordered porous structure,and high porosity.In this study,a porous carbon material derived from an MOF,named as University of Oslo-66-carbon(UiO-66-C),was synthesized using a solvothermal method and applied as an adsorbent to enrich four phenolic EDCs(bisphenol A,4-tert-octylphenol,4-nonylphenol,and nonylphenol)in water.A method combining DSPE with ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS)was established to analyze these phenolic EDCs in water.The UiO-66-C dosage,pH of water sample,adsorption time,eluent type and volume,elution time,and ion strength were optimized.Gradient elution was performed using methanol-water as the mobile phase.The target analytes were separated on an ACQUITY UPLC BEH C18 column(100 mm×2.1 mm,1.7μm),and multiple reaction monitoring(MRM)was conducted in negative electrospray ionization mode.The method exhibited a linear correlation within the range of 0.5-100μg/L for the four phenolic EDCs.The limits of detection(LODs)and quantification(LOQs)of the four phenolic EDCs were 0.01-0.13μg/L and 0.03-0.42μg/L,respectively.The precision of the method was evaluated through intra-and inter-day relative standard deviations(RSDs),with values ranging from 1.5%to 10.6%and from 6.1%to 13.2%,respectively.When applied to the detection of phenolic EDCs in tap and surface water,the spiked recoveries of the four phenolic EDCs were 77.1%-116.6%.Trace levels of 4-nonylphenol and nonylphenol were detected in surface water at levels of 1.38 and 0.26μg/L,respectively.The proposed method exhibits good accuracy and precision;thus,it provides a new rapid,efficient,and sensitive approach for the detection of phenolic EDCs in environmental water.