Zeng Eddy Y, Tsukada David, Diehl Dario W
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640 China.
Environ Sci Technol. 2004 Nov 1;38(21):5737-43. doi: 10.1021/es049680m.
Solid-phase microextraction (SPME) has been used as an in situ sampling technique for a wide range of volatile organic chemicals, but SPME field sampling of nonvolatile organic pollutants has not been reported. This paper describes the development of an SPME-based sampling method employing a poly(dimethylsiloxane) (PDMS)-coated (100-microm thickness) fiber as the sorbent phase. The laboratory-calibrated PDMS-coated fibers were used to construct SPME samplers, and field tests were conducted at three coastal locations off southern California to determine the equilibrium sampling time and compare the efficacy of the SPME samplers with that of an Infiltrex 100 water pumping system (Axys Environmental Systems Ltd., Sidney, British Columbia, Canada). p,p'-DDE and o,p'-DDE were the components consistently detected in the SPME samples among 42 polychlorinated biphenyl congeners and 17 chlorinated pesticidestargeted. SPME samplers deployed attwo locations with moderate and high levels of contamination for 18 and 30 d, respectively, attained statistically identical concentrations of p,p'-DDE and o,p'-DDE. In addition, SPME samplers deployed for 23 and 43 d, respectively, at a location of low contamination also contained statistically identical concentrations of p,p'-DDE. These results indicate that equilibrium could be reached within 18 to 23 d. The concentrations of p,p'-DDE, o,p'-DDE, or p,p'-DDD obtained with the SPME samplers and the Infiltrex 100 system were virtually identical. In particular, two water column concentration profiles of p,p'-DDE and o,p'-DDE acquired by the SPME samplers at a highly contaminated site on the Palos Verdes Shelf overlapped with the profiles obtained by the Infiltrex 100 system in 1997. The field tests not only reveal the advantages of the SPME samplers compared to the Infiltrex 100 system and other integrative passive devices but also indicate the need to improve the sensitivity of the SPME-based sampling technique.
固相微萃取（SPME）已被用作多种挥发性有机化合物的原位采样技术，但尚未见有关于SPME用于非挥发性有机污染物现场采样的报道。本文描述了一种基于SPME的采样方法的开发过程，该方法采用聚二甲基硅氧烷（PDMS）涂层（厚度为100微米）的纤维作为吸附相。经实验室校准的PDMS涂层纤维用于构建SPME采样器，并在南加州沿海的三个地点进行了现场测试，以确定平衡采样时间，并将SPME采样器的效能与Infiltrex 100抽水系统（Axys环境系统有限公司，加拿大不列颠哥伦比亚省悉尼）的效能进行比较。在42种多氯联苯同系物和17种目标氯代农药中，p,p'-滴滴伊和o,p'-滴滴伊是在SPME样品中始终能检测到的成分。分别在污染程度中等和较高的两个地点部署18天和30天的SPME采样器，获得的p,p'-滴滴伊和o,p'-滴滴伊浓度在统计学上相同。此外，分别在低污染地点部署23天和43天的SPME采样器中，p,p'-滴滴伊的浓度在统计学上也相同。这些结果表明，在18至23天内可达到平衡。用SPME采样器和Infiltrex 100系统获得的p,p'-滴滴伊、o,p'-滴滴伊或p,p'-滴滴滴的浓度几乎相同。特别是，SPME采样器在帕洛斯维德斯海架一个高度污染地点获取的p,p'-滴滴伊和o,p'-滴滴伊的两个水柱浓度剖面，与Infiltrex 100系统在1997年获得的剖面重叠。现场测试不仅揭示了SPME采样器相对于Infiltrex 100系统和其他综合被动装置的优势，还表明需要提高基于SPME的采样技术的灵敏度。
