Department of Applied Environmental Science (ITM), Stockholm University, Svante Arrhenius väg 8, SE-10691 Stockholm, Sweden.
J Chromatogr A. 2010 Jul 16;1217(29):4765-70. doi: 10.1016/j.chroma.2010.05.046. Epub 2010 May 31.
The partitioning of non-polar analytes into the silicone polydimethylsiloxane (PDMS) is the basis for many analytical approaches such as solid phase microextraction (SPME), stir bar sorptive extraction (SBSE) and environmental passive sampling. Recently, the methods have been applied to increasingly complex sample matrices. The present work investigated the possible effect of complex matrices on the sorptive properties of PDMS. First, SPME fibers with a 30 microm PDMS coating were immersed in 15 different matrices, including sediment, suspensions of soil and humic substances, mayonnaise, meat, fish, olive oil and fish oil. Second, the surface of the fibers was wiped clean, and together with matrix-free control fibers, they were exposed via headspace to 7 non-polar halogenated organic chemicals in spiked olive oil. The fibers were then solvent-extracted, analyzed, and the ratios of the mean concentrations in the matrix-immersed fibers to the control fibers were determined for all matrices. These ratios ranged from 92% to 112% for the four analytes with the highest analytical precision (i.e. polychlorinated biphenyls (PCBs) 3, 28, 52 and brominated diphenyl ether (BDE) 3), and they ranged from 74% to 133% for the other three compounds (i.e. PCBs 101, 105 and gamma-hexachlorocyclohexane (HCH)). We conclude that, for non-polar, hydrophobic chemicals, the sorptive properties of the PDMS were not modified by the diverse investigated media and consequently that PDMS is suited for sampling of these analytes even in highly complex matrices.
非极性分析物在硅氧烷聚二甲基硅氧烷（PDMS）中的分配是许多分析方法的基础，例如固相微萃取（SPME）、搅拌棒吸附萃取（SBSE）和环境被动采样。最近，这些方法已经应用于越来越复杂的样品基质。本研究考察了复杂基质对 PDMS 吸附性能的可能影响。首先，将 30 微米 PDMS 涂层的 SPME 纤维浸入 15 种不同的基质中，包括沉积物、土壤和腐殖质的悬浮液、蛋黄酱、肉类、鱼类、橄榄油和鱼油。其次，纤维表面被擦拭干净，与无基质对照纤维一起，通过顶空暴露于橄榄油中添加的 7 种非极性卤代有机化学品。然后将纤维进行溶剂萃取、分析，并确定所有基质中浸入基质纤维与对照纤维的平均浓度比值。对于四个分析物（即多氯联苯（PCBs）3、28、52 和溴化二苯醚（BDE）3），具有最高分析精度的四个分析物的比值范围为 92%至 112%，而对于另外三个化合物（即 PCBs 101、105 和γ-六氯环己烷（HCH））的比值范围为 74%至 133%。我们得出结论，对于非极性、疏水性化学物质，PDMS 的吸附性能不会被不同的研究介质改变，因此 PDMS 适合于这些分析物的采样，即使在高度复杂的基质中也是如此。
