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全氟和多氟烷基化合物(PFASs)是一类人工合成的有机化合物,具有优异的热稳定性和化学稳定性,疏水疏油、不易生物降解、高表面活性等独特的理化性质[1 − 2]. 自20世纪50年代起,PFASs被广泛应用于商业和工业领域,所涉及产品包括消防泡沫、纸板、杀虫剂、驱虫剂、润滑剂、表面处理剂、个人护理品和食品包装产品等[3 − 4]. 自2001年Giesy和Kannan首次在环境中检测出PFASs起[5] ,PFASs相继在世界各地的水体[6 − 7]、土壤[8 − 9]、空气[10]、沉积物[11]、灰尘[12]、动物[13 − 14]、人体血清[15]、尿液[16]等环境介质及生物样本中广泛检出. 由于PFASs具有环境持久性、生物累积性、多种毒性等特性[17],其进入环境后,会在一定程度上对生态环境及人类健康构成威胁[18]. 已有研究指出PFASs可以通过各种途径进入到人体[19],例如,PFASs可以通过胎盘屏障,进入到胎儿体内,进而对胎儿造成宫内暴露[20]. 近年来,针对于PFASs母婴暴露的相关研究已经成为研究热点. 在以往研究中,研究人员主要通过监测母血、脐带血以及胎盘等样品来探究PFASs的宫内暴露特征[21]. 然而,上述样品采样过程是侵入性的,可能会对采样对象造成损伤,导致难以开展大范围、系统性研究. Vizcaino等[22]指出包括PFASs在内的多种持久性有机污染物可通过胎盘转移进入到胎儿体内,并且在胎便中形成不同程度的累积. 因此,开展胎便中的PFASs的痕量分析研究,可获得PFASs对胎儿的产前暴露相关信息,进而为评估其产前暴露风险提供数据支撑.
胎便指胎儿出生后的几次排便,是一种黑绿色、无味、粘稠的粘性物质. 胎便由水、胃肠道和皮肤脱落的上皮细胞、胎毛、各种胰腺和肠道分泌物,以及吞咽的羊水残留物组成[23],它是一种高度复杂的基质. 与其他研究中使用的胎儿基质(脐带血、尿液和血液)相比,胎便样本数量多,易于收集,非侵入性,更为重要的是胎便可将污染物的累计代谢考虑在内. 除此之外,胎便的样品收集窗口相对较宽,即胎儿出生后3天内的胎便均可用于分析且效果最佳[23].
胎便中积累了妊娠期间暴露于胎儿的多种外源性化合物[24],但其复杂的基质成分导致对其中的污染物进行痕量分析具有一定挑战. 目前,关于胎便中PFASs的分析检测方法仍鲜有报道并亟待研究. 基于此,本研究利用离线固相萃取结合高效液相色谱串联质谱法,建立了胎便中14种PFASs的分析方法. 该方法采用乙腈/水(9∶1,V/V)对胎便进行提取,Envi-Carb与Oasis WAX进行萃取净化,具有操作简便,灵敏度高,准确度和精密度较高的优点. 该方法的建立可为胎便中PFASs的分析检测提供技术基础,为研究PFASs的母婴传递和评估胎儿产前PFASs暴露风险提供技术支撑.
固相萃取结合高效液相色谱-串联质谱测定胎便中14种全氟和多氟烷基化合物
Determination of 14 kinds of perfluorinated and polyfluoroalkyl compounds in meconium by solid phase extraction-high performance liquid chromatography-tandem mass spectrometry
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摘要: 全氟和多氟烷基化合物(PFASs)是一类人工合成的物质,由于其热稳定、疏水、疏油等优良性质而被广泛使用于生活和生产中. PFASs具有环境持久性、生物累积性、多种毒性等特性,且可以通过胎盘屏障进入到胎儿体内,进而对胎儿健康产生潜在危害. 胎便中积累了妊娠期间暴露于胎儿的外源性化合物,可用于监测PFASs对胎儿的宫内暴露特征. 本研究基于固相萃取结合高效液相色谱-串联质谱技术,建立了胎便中14种PFASs的分析方法. 采用乙腈/水(9∶1,V/V)对0.2 g冻干胎便样品进行超声提取,提取液经Envi-carb和Oasis WAX小柱固相萃取,0.1%氨甲醇洗脱. 以10 mmol·L−1乙酸铵水溶液和乙腈作为流动相对目标化合物进行梯度洗脱,采用Acquity UPLC BEH C18色谱柱进行分离,基于多反应监测负离子模式采集,内标法定量. 结果表明,在2、5、20 ng·g−1的加标浓度下,14种PFASs的回收率为65%—149%,相对标准偏差为3%—22%,方法检出限(MDLs)为0.001—0.149 ng·g−1,方法定量限(MQLs)为0.003—0.495 ng·g−1. 使用该方法测定了10个胎便样品,ΣPFASs浓度范围为<MDLs—2.49 ng·g−1. 该方法操作简单、便捷、灵敏度高且定量准确,为系统性研究胎便中PFASs的赋存特征及暴露风险提供了技术基础.
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关键词:
- 胎便 /
- 全氟和多氟烷基化合物 /
- 高效液相色谱-串联质谱 /
- 固相萃取.
Abstract: Perfluorinated and polyfluoroalkyl compounds (PFASs) are a kind of synthetic substances, which have been widely used in daily life and production because of their excellent properties such as heat stability, hydrophobic and oleophobic. PFASs have the characteristics of environmental persistence, bioaccumulation, and multiple toxicity, and can pass across the placental barrier into the fetal, thus posing potential exposure risk to fetal health. Generally, the meconium accumulates exogenous compounds that were exposed to the fetus during pregnancy, as such, the meconium can be used to monitor the exposure characteristics of PFASs to the fetus. A method was established for the determination of 14 kinds of PFASs in meconium by solid phase extraction high performance liquid chromatography-tandem mass spectrometry (SPE HPLC-MS/MS). The freeze-drying meconium sample (0.2 g) was ultrasonically extracted by acetonitrile (ACN)/water (9:1, V/V) and then was extracted by Envi-carb and Oasis WAX cartridges, eluted with 0.1% ammonia in methanol. The sample was separated by using an Acquity UPLC BEH C18 column and eluted gradiently with 10 mmol·L−1 ammonium acetate and acetonitrile as the mobile phase. The samples were detected by tandem mass spectrometry under multiple reaction monitoring (MRM) mode with negative electrospray ionization, and quantified by internal standard method. Results showed that the recoveries of PFASs were 65%—149% at spiked levels of 2, 5, and 20 ng·g−1, and the relative standard deviations (RSD) were 3%—22%. The method detection limits (MDLs) and the method quantitation limits (MQLs) were in the range of 0.001—0.149 ng·g−1 and 0.003—0.495 ng·g−1, respectively. The method was used to detect 10 meconium samples, and the concentrations ranged from <MDLs to 2.49 ng·g−1. This established method is simple, convenient, sensitive and accurate, which will provide a technical basis for the systematic study of the occurrence as well as exposure risk of PFASs in meconium. -
表 1 14种PFASs的名称、缩写、化学式及CAS号
Table 1. Full names, abbreviations, formulas, CAS number of 14 PFASs
化合物名称(中文)
Full names in Chinese化合物名称(英文)
Full names in English缩写
Abbreviations化学式
FormulasCAS号
CAS number6:2氯化聚氟烷基醚磺酸 6:2 Chlorinated Polyfluoroalkyl ether sulfonic acid 6:2 Cl-PFESA C8ClF16SO4H 756426-58-1 8:2氯化聚氟烷基醚磺酸 8:2 Chlorinated Polyfluoroalkyl ether sulfonic acid 8:2 Cl-PFESA C10ClF20SO4H 83329-89-9 全氟辛酸 Perfluorooctanoic acid PFOA C8F15O2H 335-67-1 全氟壬酸 Perfluorononanoic acid PFNA C9F17O2H 375-95-1 全氟癸酸 Perfluorodecanoic acid PFDA C10F19O2H 335-76-2 全氟十一烷酸 Perfluoroundecanoic acid PFUdA C11F21O2H 2058-94-8 全氟十二烷酸 Perfluorododecanoic acid PFDoA C12F23O2H 307-55-1 全氟十三烷酸 Perfluorotridecanoic acid PFTrDA C13F25O2H 72629-94-8 全氟己基磺酸 Perfluorohexanesulfonic acid PFHxS C6F13SO3H 355-46-4 全氟庚基磺酸 Perfluoroheptanesulfonic acid PFHpS C7F15SO3H 375-92-8 全氟辛基磺酸 Perfluorooctanesulfonic acid PFOS C8F17SO3H 1763-23-1 全氟壬基磺酸 Perfluorononanesulfonic acid PFNS C9F19SO3H 68259-12-1 全氟癸基磺酸 Perfluorodecanesulfonic acid PFDS C10F21SO3H 335-77-3 全氟十二烷磺酸 Perfluorododecanesulfonic acid PFDoS C12F25SO3H 79780-39-5 表 2 14种PFASs的质谱多反应监测参数
Table 2. MRM parameters of mass spectrometry for 14 PFASs
化合物
Compound前体离子(m/z)
Precursor
ion子离子(m/z)
Product ionQ1 Pre偏差
Q1 Pre
deviation碰撞能/eV
Collision
energyQ3 Pre偏差/V
Q3 Pre
deviation对应内标
Mass labeled
standards6:2 Cl-PFESA 530.9 351.0* 26 27 15 13C4-PFOS 83.1 38 26 29 8:2 Cl-PFESA 630.9 450.9* 29 20 20 13C4-PFOS 83.1 34 30 30 PFOA 413.1 369.0* 29 11 24 13C4-PFOA 169.1 14 18 16 PFNA 463.1 419.0* 16 11 28 13C5-PFNA 463.0 219.1 13 17 20 PFDA 513.1 469.1* 26 12 22 13C2-PFDA 219.1 24 17 14 PFUdA 562.9 518.9* 20 13 34 13C2-PFUdA 269.1 20 18 24 PFDoA 612.9 568.9* 22 12 26 13C2-PFUdA 169.1 22 27 26 PFTrDA 662.9 618.9* 24 13 20 13C2-PFUdA 169.1 24 26 28 PFHxS 398.9 99.0* 14 38 29 18O2-PFHxS 80.0 14 55 26 PFHpS 449.0 99.0* 16 39 30 18O2-PFHxS 80.0 16 55 28 PFOS 498.9 99.0* 17 40 29 13C4-PFOS 80.0 14 54 26 PFNS 548.9 79.9 20 55 25 13C4-PFOS 99.0* 20 47 30 PFDS 598.9 99.0* 22 49 30 13C4-PFOS 80.0 22 55 29 PFDoS 698.9 99.0* 20 51 14 13C4-PFOS 80.0 24 55 25 13C4-PFOA 417.1 372.1* 14 11 17 — 13C5-PFNA 468.1 423.0* 16 12 27 — 13C2-PFDA 515.1 470.1* 26 12 21 — 13C2-PFUdA 565.1 519.9* 20 12 32 — 18O2-PFHxS 402.9 84.0 19 52 26 — 103.0* 19 36 30 13C4-PFOS 502.9 80.0 24 53 27 — 99.0* 19 46 27 * 定量离子Quantitative ion 表 3 14种PFASs的线性范围、回归方程、相关系数、检出限与定量限
Table 3. Linear ranges, regression equations, correlation coefficients, MDLs and MQLs of 14 kinds of PFASs
化合物
Compound线性范围/(μg·L−1)
Linear
range回归方程
Regression
equation相关系数
Correlation
coefficient (r)检出限/(ng·g−1)
MDLs定量限/(ng·g−1)
MQLs6:2 Cl-PFESA 0.1—50 y=1.3932x+0.0199 0.997 0.002 0.005 8:2 Cl-PFESA 0.1—50 y=1.0309x+0.0261 0.997 0.001 0.003 PFOA 0.1—50 y=0.1993x+0.0161 0.997 0.006 0.020 PFNA 0.1—50 y=0.2244x+0.0042 0.996 0.006 0.018 PFDA 0.1—50 y=0.2412x+0.0073 0.998 0.003 0.011 PFUdA 0.1—50 y=0.2241x+0.0094 0.998 0.007 0.022 PFDoA 0.1—50 y=0.2457x+0.0026 0.995 0.004 0.013 PFTrDA 0.1—50 y=0.2100x+0.0097 0.995 0.008 0.027 PFHxS 0.1—50 y=0.2224x+0.0045 0.997 0.149 0.495 PFHpS 0.1—50 y=0.2858x+0.0079 0.996 0.008 0.025 PFOS 0.1—50 y=0.1127x-0.0028 0.995 0.036 0.120 PFNS 0.1—50 y=0.2018x+0.0014 0.995 0.004 0.012 PFDS 0.1—50 y=0.2018x+0.0063 0.996 0.002 0.007 PFDoS 0.1—50 y=0.1595x+0.0034 0.996 0.002 0.007 表 4 样品加标回收率结果
Table 4. Recovery results of spiked samples
化合物
Compound加标浓度/(ng·g−1)
Spiking concentrations回收率/%
Recovery rate相对标准偏差/%
RSD6:2 Cl-PFESA 2 97 4 5 93 5 20 89 3 8:2 Cl-PFESA 2 99 4 5 97 6 20 94 3 PFOA 2 113 13 5 79 19 20 78 3 PFNA 2 88 8 5 81 4 20 82 4 PFDA 2 93 8 5 87 6 20 87 6 PFUdA 2 88 5 5 84 4 PFUdA 20 84 6 PFDoA 2 79 13 5 72 13 20 75 14 PFTrDA 2 98 20 5 77 19 20 93 16 PFHxS 2 65 12 5 87 11 20 93 5 PFHpS 2 144 10 5 149 8 20 128 8 PFOS 2 136 22 5 100 8 20 93 18 PFNS 2 115 5 5 114 3 20 99 19 PFDS 2 99 6 5 107 4 20 102 4 PFDoS 2 82 16 5 72 12 20 94 7 表 5 各分析物基质效应评价
Table 5. Matrix effect evaluation for each analyte
化合物
Compund溶剂曲线斜率
Slope of solvent curve基质效应曲线斜率
Slope of the matrix effect curve基质效应/%
Matrix effect基质效应评价
Matrix effect evaluation6:2 Cl-PFESA 1.6618 1.3932 16 弱基质效应 8:2 Cl-PFESA 1.1880 1.0309 13 弱基质效应 PFOA 0.2074 0.1993 4 弱基质效应 PFNA 0.2052 0.2244 9 弱基质效应 PFDA 0.2170 0.2412 11 弱基质效应 PFUdA 0.2003 0.2241 12 弱基质效应 PFDoA 0.1862 0.2457 32 中等程度基质效应 PFTrDA 0.1816 0.2100 16 弱基质效应 PFHxS 0.2109 0.2224 5 弱基质效应 PFHpS 0.2317 0.2858 23 中等程度基质效应 PFOS 0.0836 0.1127 35 中等程度基质效应 PFNS 0.1852 0.2018 9 弱基质效应 PFDS 0.2191 0.2018 8 弱基质效应 PFDoS 0.1858 0.1595 14 弱基质效应 表 6 14种PFASs在胎便中的测定值
Table 6. Determination concentration of 14 kinds of PFASs in meconium
化合物
Compounds检出率/%
Detection rate浓度/(ng·g−1)
Concentrations最小值
Min第一四分位数
P25中位数
Median第三四分位数
P75最大值
Max6:2 Cl-PFESA 20 <MDLs <MDLs <MDLs <MDLs 0.073 8:2 Cl-PFESA 0 <MDLs <MDLs <MDLs <MDLs <MDLs PFOA 100 0.064 0.083 0.106 0.126 0.326 PFNA 70 <MDLs <MDLs 0.008 0.013 0.029 PFDA 20 <MDLs <MDLs <MDLs <MDLs 0.018 PFUdA 60 <MDLs <MDLs 0.015 0.036 0.089 PFDoA 30 <MDLs <MDLs <MDLs <MDLs 0.007 PFTrDA 70 <MDLs <MDLs 0.015 0.093 0.173 PFHxS 100 0.531 1.244 1.633 1.826 2.486 PFHpS 60 <MDLs <MDLs <MDLs 0.028 0.073 PFOS 80 <MDLs 0.036 0.508 0.669 1.778 PFNS 30 <MDLs <MDLs <MDLs 0.010 0.079 PFDS 10 <MDLs <MDLs <MDLs <MDLs 0.101 PFDoS 0 <MDLs <MDLs <MDLs <MDLs <MDLs -
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