一次性固相微萃取-高效液相色谱法测定环境水样中的3种多环芳烃

以涂有聚二甲基硅氧烷(PDMS)的石英光导纤维作为固相微萃取纤维,建立了一次性固相微萃取与高效液相色谱联用测定环境水样中的菲、荧蒽和屈3种多环芳烃(PAHs)的方法。实验考察了解吸时间、萃取时间、搅拌速度、盐效应以及样品溶液pH值对萃取效率的影响,优化得到的萃取和解吸条件为: 于60 mL样品溶液中放入两段萃取纤维(1.5 cm)和1.2 g氯化钠,在1200 r/min搅拌速度下萃取60 min,取出萃取纤维并转入120 μL甲醇中密封静置解吸24 h后,取20 μL解吸液进行液相色谱测定。该方法对于菲、荧蒽和屈的检出限分别为0.17、0.17和0.08 μg/L;精密度(以测定0.5 μg/L PAHs标准溶液6次的相对标准偏差计)小于8%;实际样品中3种PAHs的加标回收率为80.0%～107%。该方法快速简便,纤维一次性使用,克服了污染物在纤维上残留的问题。

Determination of three polycyclic aromatic hydrocarbons in environmental water samples by disposable fibers of solid-phase microextraction coupled with high performance liquid chromatograph

A method was developed for the determination of phenanthrene, fluoranthene and chrysene in environmental water samples using disposable fibers of solid-phase microextraction (SPME) coupled with high performance liquid chromatograph (HPLC). The disposable SPME fibers for the extraction were added into the sample (60 mL) spiked with 20 g/L NaCl. After extracted for 60 min at a stirring speed of 1200 r/min, the fibers were collected and immersed in 120 μL methanol for 24 h to desorb the analytes for the HPLC analysis followed. Under the optimized conditions, the respective detection limits were 0.17 μg/L for phenanthrene and fluoranthene, and 0.08 μg/L for chrysene, and the relative standard deviations (RSDs) were less than 8% (n=6). The method was successfully applied to analyze real environmental water samples with spiked recoveries in the range of 80.0%~107%. This method is cost-effective, easy to operate, and overcomes the carry-over problem of the pollutants on the fibers.