National Exposure Research Laboratory, U.S. Environmental Protection Agency, Las Vegas, NV 89193-3478, USA.
Anal Chim Acta. 2012 Oct 1;745:38-44. doi: 10.1016/j.aca.2012.07.031. Epub 2012 Jul 27.
An efficient and reliable analytical method was developed for the sensitive and selective quantification of pyrethroid pesticides (PYRs) in house dust samples. The method is based on selective pressurized liquid extraction (SPLE) of the dust-bound PYRs into dichloromethane (DCM) with analysis by gas chromatography/mass spectrometry. Various adsorbents and combinations of extraction solvents and temperatures were evaluated to achieve a high-throughput sample preparation that eliminates the post-extraction cleanup step. The final method used sulfuric acid-impregnated silica (acid silica) and neutral silica together in the extraction cell with the dust sample to provide both extraction and cleanup simultaneously. The optimal ratio of dust/acid silica/silica was 1:0.8:8. The extraction was performed at 2000 psi, at 100°C with DCM for 5 min in three cycles. Method precision and accuracy were evaluated by the analysis of triplicate aliquots of the dust samples and the samples fortified with the target PYRs. The accuracy measured as the recoveries of the PYRs in the fortified samples ranged from 85% to 120%. The precision measured as the relative standard deviation of replicate samples was within ±25%. The SPLE method was applied to 20 house dust samples collected from households that participated in two field studies regarding exposures to pesticides and other pollutants. Similar concentrations of target PYRs were obtained for the SPLE and a stepwise extraction/cleanup procedure. The SPLE procedure reduces organic solvent consumption and increases the sample throughput when compared with a traditional stepwise extraction and cleanup procedure. This study demonstrates that the SPLE procedure can be applied to complex dust matrices for analysis of PYRs for large scale exposure or environmental monitoring studies.
开发了一种用于在房屋灰尘样品中灵敏且选择性地定量分析拟除虫菊酯类农药（PYRs）的高效可靠的分析方法。该方法基于将灰尘中结合的 PYRs 用二氯甲烷（DCM）通过气相色谱/质谱法选择性加压液体萃取（SPLE）进行分析。评估了各种吸附剂以及萃取溶剂和温度的组合，以实现高通量的样品制备，从而消除了萃取后清理步骤。最终方法在萃取细胞中使用硫酸浸渍的硅胶（酸硅胶）和中性硅胶与灰尘样品一起使用，同时提供萃取和清理功能。灰尘/酸硅胶/硅胶的最佳比例为 1:0.8:8。萃取在 2000 psi、100°C 下用 DCM 进行 5 分钟的三个循环。通过分析灰尘样品的三倍空白样和添加目标 PYRs 的样品来评估方法的精密度和准确性。以添加到样品中的 PYRs 的回收率来衡量准确度，其范围在 85%到 120%之间。以重复样品的相对标准偏差衡量精密度，在±25%以内。SPLE 方法应用于从参与两项关于暴露于农药和其他污染物的现场研究的家庭中收集的 20 个房屋灰尘样品。对于 SPLE 和逐步提取/清理程序，均获得了目标 PYRs 的相似浓度。与传统的分步提取和清理程序相比，SPLE 程序减少了有机溶剂的消耗并增加了样品通量。本研究表明，SPLE 程序可应用于复杂的灰尘基质，用于大规模暴露或环境监测研究中分析 PYRs。
