Serôdio P, Nogueira J M F
Chemistry and Biochemistry Department, Faculty of Sciences, University of Lisbon, Campo Grande Ed. C8, 1749-016, Lisbon, Portugal.
Water Res. 2006 Jul;40(13):2572-82. doi: 10.1016/j.watres.2006.05.002. Epub 2006 Jun 23.
Stir bar sorptive extraction with liquid desorption followed by large volume injection and capillary gas chromatography coupled to mass spectrometry (SBSE-LD/LVI-GC-MS), had been applied for the determination of ultra-traces of seven-phthalates (dimethyl phthalate, diethyl phthalate, di-n-butyl phthalate, butyl benzyl phthalate, bis(2-ethylhexyl) adipate, bis(2-ethylhexyl) phthalate and bis(1-octyl) phthalate) in drinking water samples, which are included in the priority lists set by several international regulatory organizations. Instrumental calibration under the selected-ion monitoring mode acquisition (LVI-GC-MS(SIM)), experimental parameters that could affect the SBSE-LD efficiency, as well as, the control of the contamination profile are fully discussed. Throughout systematic assays on 30 mL water samples spiked at the 0.40 microg/L level, it had been established that stir bars coated with 47 microL of polydimethylsiloxane, an equilibrium time of 60 min (1,000 rpm) and methanol as back extraction solvent, allowed the best analytical performance to monitor phthalates in water matrices. From the data obtained, good accuracy and a remarkable reproducibility (< 14.8%) were attained, providing experimental recovery data in agreement with the theoretical equilibrium described by the octanol-water partition coefficients (K(PDMS/W) approximately K(O/W)), with the exception of bis(2-ethylhexyl) adipate, bis(2-ethylhexyl) phthalate and bis(1-octyl) phthalate, for which lower yields were measured. Additionally, a remarkable linear dynamic range between 25 and 2,000 ng/L (r(2)>0.99) and low detection limits (3-40 ng/L) were also achieved for the seven-phthalates studied. The application of the present method to monitor phthalates in tap and bottled mineral water samples, allowed convenient selectivity and high sensitivity up to 1.0 microg/L level, using the standard addition methodology. The proposed method showed to be feasible and sensitive with a low sample volume requirement to monitor phthalates in drinking water matrices at the ultra-trace level, in compliance with international regulatory directives on water quality.
搅拌棒吸附萃取结合液体解吸、大体积进样以及毛细管气相色谱 - 质谱联用（SBSE - LD/LVI - GC - MS）已用于测定饮用水样品中七种邻苯二甲酸酯（邻苯二甲酸二甲酯、邻苯二甲酸二乙酯、邻苯二甲酸二正丁酯、邻苯二甲酸丁苄酯、己二酸二（2 - 乙基己基）酯、邻苯二甲酸二（2 - 乙基己基）酯和邻苯二甲酸二（1 - 辛基）酯）的超痕量，这些物质都在多个国际监管组织制定的优先清单中。文中充分讨论了在选择离子监测模式采集（LVI - GC - MS(SIM)）下的仪器校准、可能影响SBSE - LD效率的实验参数以及污染情况的控制。通过对加标浓度为0.40 μg/L的30 mL水样进行系统分析，已确定涂覆47 μL聚二甲基硅氧烷的搅拌棒、60分钟（1000转/分钟）的平衡时间以及甲醇作为反萃取溶剂，能实现对水基质中邻苯二甲酸酯的最佳分析性能。根据所得数据，除己二酸二（2 - 乙基己基）酯、邻苯二甲酸二（2 - 乙基己基）酯和邻苯二甲酸二（1 - 辛基）酯的回收率较低外，其他邻苯二甲酸酯的回收率良好且重现性显著（< 14.8%），实验回收率数据与由辛醇 - 水分配系数描述的理论平衡（K(PDMS/W) ≈ K(O/W)）相符。此外，对于所研究的七种邻苯二甲酸酯，还实现了25至2000 ng/L之间显著的线性动态范围（r(2)>0.99）以及低检测限（3 - 40 ng/L）。采用标准加入法，将本方法应用于监测自来水和瓶装矿泉水样品中的邻苯二甲酸酯，在高达1.0 μg/L的水平下具有良好的选择性和高灵敏度。所提出的方法对于监测饮用水基质中超痕量邻苯二甲酸酯是可行且灵敏的，对样品体积要求低，符合国际水质监管指令。
