Dasu Kavitha, Nakayama Shoji F, Yoshikane Mitsuha, Mills Marc A, Wright J Michael, Ehrlich Shelley
National Research Council, The National Academies of Sciences, Engineering, Medicine, 500 Fifth Street, NW, Washington, DC 20001, USA; National Risk Management Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH, USA.
Centre for Health and Environmental Risk Research, National Institute for Environmental Studies, Tsukuba, Japan.
J Chromatogr A. 2017 Apr 21;1494:46-54. doi: 10.1016/j.chroma.2017.03.006. Epub 2017 Mar 6.
In epidemiological research, it has become increasingly important to assess subjects' exposure to different classes of chemicals in multiple environmental media. It is a common practice to aliquot limited volumes of samples into smaller quantities for specific trace level chemical analyses. A novel method was developed for the determination of 14 perfluorinated alkyl acids (PFAAs) in small volumes (10mL) of drinking water using off-line solid phase extraction (SPE) pre-treatment followed by on-line pre-concentration on a WAX column before analysis on column-switching high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). In general, large volumes (100-1000mL) have been used for the analysis of PFAAs in drinking water. The current method requires approximately 10mL of drinking water concentrated by using an SPE cartridge and eluted with methanol. A large volume injection of the extract was introduced on to a column-switching HPLC-MS/MS using a mix-mode SPE column for the trace level analysis of PFAAs in water. The recoveries for most of the analytes in the fortified laboratory blanks ranged from 73±14% to 128±5%. The lowest concentration minimum reporting levels (LCMRL) for the 14 PFAAs ranged from 0.59 to 3.4ng/L. The optimized method was applied to a pilot-scale analysis of a subset of drinking water samples from an epidemiological study. These samples were collected directly from the taps in the households of Ohio and Northern Kentucky, United States and the sources of drinking water samples are both surface water and ground water, and supplied by different water distribution facilities. Only five PFAAs, perfluoro-1-butanesulfonic acid (PFBS), perfluoro-1- -hexanesulfonic acid (PFHxS), perfluoro-1-octanesulfonic acid (PFOS), perfluoro-n-heptanoic acid (PFHpA) and perfluoro-n-octanoic acid (PFOA) are detected above the LCMRL values. The median concentrations of these five PFAAs detected in the samples was ≤4.1ng/L with PFOS at 7.6ng/L and PFOA at 10ng/L. Concentrations of perfluoro-1-decanesulfonic acid, PFDS and other perfluoroalkyl carboxylic acids were below the LCMRL values.
在流行病学研究中，评估受试者在多种环境介质中接触不同类别化学物质的情况变得越来越重要。将有限体积的样品分成较小的量用于特定痕量水平化学分析是一种常见做法。开发了一种新方法，用于测定小体积（10mL）饮用水中的14种全氟烷基酸（PFAA），该方法采用离线固相萃取（SPE）预处理，然后在柱切换高效液相色谱串联质谱（HPLC-MS/MS）分析之前，在WAX柱上进行在线预浓缩。一般来说，大体积（100 - 1000mL）已用于饮用水中PFAA的分析。当前方法需要大约10mL饮用水，通过SPE柱进行浓缩并用甲醇洗脱。将大量提取物注入柱切换HPLC-MS/MS，使用混合模式SPE柱对水中的PFAA进行痕量水平分析。在加标实验室空白中，大多数分析物的回收率在73±14%至128±5%之间。14种PFAA的最低浓度最低报告水平（LCMRL）范围为0.59至3.4ng/L。该优化方法应用于一项流行病学研究中一部分饮用水样品的中试规模分析。这些样品直接从美国俄亥俄州和肯塔基州北部家庭的水龙头采集，饮用水样品的来源既有地表水也有地下水，由不同的供水设施提供。仅检测到五种PFAA，全氟-1-丁烷磺酸（PFBS）、全氟-1-己烷磺酸（PFHxS）、全氟-1-辛烷磺酸（PFOS）、全氟正庚酸（PFHpA）和全氟正辛酸（PFOA）高于LCMRL值。样品中检测到的这五种PFAA的中位浓度≤4.1ng/L，其中PFOS为7.6ng/L，PFOA为10ng/L。全氟-1-癸烷磺酸、PFDS和其他全氟烷基羧酸的浓度低于LCMRL值。
