高效液相色谱-串联质谱联用测定人血液中的全氟化合物

采用HPLC-ESI-MS/MS联用技术,建立了分析血样中9种全氟化合物(PFCs)的方法.以13C4标记的PFOS (MPFOS)作为内标物.以C18反相柱为分析柱,甲醇、醋酸铵为梯度洗脱淋洗液,9种分析物包括全氟己烷磺酸(PFHxS)、全氟庚酸(PFHpA)、全氟辛酸 (PFOA)、全氟辛烷磺酸(PFOS)、全氟壬酸(PFNA)、全氟癸酸(PFDA)、全氟十一酸(PFUnDA)、全氟十二酸(PFDoDA)和全氟十四酸(PFTA),在15 min内即可达到良好的分离.在血样前处理中,采用MTBE液-液萃取和固相萃取相结合的方法,进一步净化样品以延长色谱柱寿命;比较了4种固相萃取小柱对全氟化合物的萃取性能,最终选定HLB柱(Waters).本研究还讨论了两种C18反相柱Acclaim 120(50 mm×4.6 mm, 3 μm)和Acclaim120 (250 mm×4.6 mm, 5 μm)(Dionex) 对PFCs的分析性能,在本实验条件下,两种色谱柱具有相似的分离性能及检出限,线性范围在0.1～50 μg/L之间 (r≥0.9957);对于血液样品该方法的检出限在0.03～0.8 μg/L之间.本研究将该方法成功地应用于血样实际样品中全氟化合物的测定,加标回收除PFTA较低外,其它化合物均在74.2%～118.1%之间.     

液相色谱-串联质谱法快速测定电子电气产品中全氟辛酸和全氟辛烷磺酸

建立了液相色谱-串联质谱法快速测定电子电气产品中全氟辛酸(PFOA)和全氟辛烷磺酸(PFOS)的分析方法。采用加速溶剂萃取提取样品中PFOA和PFOS,二氯甲烷作溶剂,外标法定量,LC-MS/MS分析时间1 m in。电子电气产品中PFOS不同加标质量分数(0.25,0.75和1.25 mg/kg)的平均回收率分别为:91.6%、92.8%和94.7%;PFOA不同加标质量分数(0.50,1.25和2.25 mg/kg)的平均回收率分别为:90.1%、91.5%和93.4%;PFOS和PFOA测定的相对标准偏差分别为2.8%~3.3%和4.2%~4.9%。测定了金属框架涂层和氟聚合物材料中PFOS和PFOA的含量,PFOS含量分别为16μg/m2和0.89%,PFOA未检出     

中空纤维膜萃取电喷雾电离质谱测定水中的全氟化合物

采用中空纤维膜( HF)做固相微萃取( SPME)材料,与常压离子化质谱( AMS)联用,分析水中全氟庚酸(PFHpA)、全氟辛酸(PFOA)、全氟壬酸(PFNA)、全氟癸酸(PFDA)、全氟辛烷磺酸(PFOS)、全氟十一酸(PFuDA)和全氟十二酸(PFDoA)7种全氟化合物(Perfluorinated compounds, PFCs)。对萃取时间和萃取溶液pH值进行了优化,质谱在负模式下使用选择反应监测扫描( SRM),并使用同位素内标13 C4-PFOS和13 C4-PFOA进行定量分析。结果表明,本方法对7种PFCs均有良好的线性(R2>0.99);除了PFHpA外,其它6种PFCs化合物的检出限为0.8~2.7 ng/L,定量限为2.7~8.9 ng/L;其中5种PFCs的富集倍数超过200倍。实际水样中(自来水和珠江水)7种PFCs均未检出,PFCs加标浓度在40和400 ng/L时,自来水的回收率范围分别为88.5%~108.3%和94.2%~116.7%,珠江水的回收率范围分别为75.0%~102.6%和82.1%~97.6%。     

全氟辛酸和全氟辛烷磺酸人体暴露途径解析及其污染控制技术*

全氟辛酸（PFOA）和全氟辛烷磺酸（PFOS）是人工合成全氟化合物的典型代表。近年来,大量的环境调查数据表明它们普遍存在于多种环境介质、生物体甚至人体中,呈现出全球分布的态势,具有环境持久性和生物富集性,对人体健康存在潜在的危害,已成为一类新的环境持久性有机污染物而引起人们广泛的关注。本文介绍了PFOA和PFOS的环境来源和传输途径,解析了人体暴露的三种主要途径以及在食物、饮用水和空气/灰尘中的污染现状,并就围绕着它们所开展的污染控制技术方面的研究进行了评述。在此基础上,通过分析目前研究中所存在的问题,对今后的发展方向和研究重点进行了展望。     

离子液体分散液液微萃取-超高效液相色谱-串联质谱法测定食品接触材料中全氟辛酸和全氟辛烷磺酸的迁移量

建立了一种基于离子液体分散液液微萃取前处理技术的食品接触材料中全氟辛酸和全氟辛烷磺酸迁移量的超高效液相色谱-串联质谱测定方法。水、10%（体积分数）乙醇溶液和4%（体积分数）乙酸溶液作为3种水性食品模拟物与食品接触材料充分接触,进行迁移试验,对迁移液采用离子液体分散液液微萃取技术进行目标物的萃取富集,考察了萃取剂种类和用量、涡旋时间、盐浓度、离心速率及时间等关键因素对食品模拟物中全氟辛酸和全氟辛烷磺酸萃取效率的影响。使用Waters ACQUITY UPLC BEH Shield RP18色谱柱（50 mm×2.1 mm,1.7 μm）,以乙腈和水为流动相,梯度洗脱分离,在电喷雾负离子模式下,采用多反应监测模式进行定性及定量分析。结果表明,全氟辛酸和全氟辛烷磺酸在各自范围内线性关系良好（r²>0.99）,检出限分别为0.5和1 μg/L,定量限分别为2和5 μg/L;在低、中、高3个添加水平下全氟辛酸和全氟辛烷磺酸的平均回收率为86.4%~116.9%,相对标准偏差为4.3%~14.4%（n=6）。该方法准确高效、环境友好,适用于食品接触材料中全氟辛酸和全氟辛烷磺酸迁移量的检测。     

纺织品中全氟辛酸及全氟辛磺酰基化合物的气相色谱-μECD测试方法

建立了超声波辅助萃取-气相色谱-微电子捕获检测器测定纺织品中全氟辛酸(PFOA)及全氟辛磺酰基化合物(PFOS)的方法。通过单因子选择实验、正交实验等方法建立了纺织品中PFOA和PFOS的超声波萃取方法和PFOA的衍生反应条件。并采用加大流速和降低温度的方法,实现了3种PFOA和PFOS混合物的气相色谱分离及测试。方法的检测限为0.00591~0.02319μg/g;精密度为2.1%~9.7%;加标回收率为92.2%~101.9%。方法适用于纺织品中痕量PFOA和PFOS的监测分析。     

牛奶、母乳中全氟化合物分析方法的研究

建立了HPLC-ESI-MS/MS联用技术测定奶制品中12种全氟化合物(PFCs)的方法.12种全氟化合物包括9种常见PFCs和2种调聚酸及一种全氟磺酰胺.对比了MTBE液-液萃取、甲酸、乙腈和甲醇萃取这4种萃取方法对12种全氟化合物的萃取和回收效果.最终选用甲醇作为萃取溶剂,并选取WAX作为固相萃取柱对萃取的溶液进行净化,方法对12种PFCs的加标回收在83.5%～113.3%之间,检出限0.005～0.092 μg/L.最后完成了对纯牛奶,早餐奶和母乳样品中12种PFCs的分析.     

全氟辛烷磺酸水样的前处理技术及固相微萃取剂的研究进展

全氟辛烷磺酸及其盐(PFOS)广泛应用于纺织品、皮革、家具等上千种工业和日用生活用品的生产中,由于具有多脏器毒性,被列为继多氯联苯、有机氯农药和二噁英之后的又一种新型持久性有机污染物.因此,PFOS的准确监测对环境PFOS污染的预警预报具有重要的意义.PFOS在样品中含量低,因此样品前处理技术是准确分析的关键.本文对目...     

应用于全氟辛烷磺酸萃取富集的全氟癸基修饰毛细管硅胶整体柱的制备及应用

利用溶胶-凝胶法,经过烷氧基硅烷的水解、硅羟基的缩聚、凝胶化、陈化、中孔制备、干燥和表面修饰等步骤制备了全氟癸基修饰的毛细管硅胶整体柱。采用该整体柱对全氟辛烷磺酸(PFOS)进行萃取富集,考察其富集特性和效率,并与传统的C18毛细管硅胶整体柱进行对比。结果表明,全氟癸基修饰毛细管硅胶整体柱(15 cm×75 μm)对PFOS具有更高的吸附量和更好的富集选择性,其平均吸附量可以达到75 ng;样品中PFOS的质量浓度为0.25 mg/L时,富集倍数平均可以达到29倍。此全氟癸基修饰毛细管硅胶整体柱对PFOS具有良好的萃取富集性能,可用于水质中痕量PFOS的萃取富集。     

近岸及河口海水中全氟化合物的固相萃取富集/超高效液相色谱-串联质谱测定

建立了近岸及河口海水中全氟辛基磺酸(PFOS)、全氟辛酸(PFOA)、全氟十一酸(PFUn A)、全氟十二酸(PFDo A)、全氟十三酸(PFTr DA)、全氟十四酸(PFTA)6种全氟化合物(PFCs)的超高效液相色谱-串联质谱(UHPLC-MS/MS)测定方法。使用C18固相萃取小柱对500 m L水样中的目标物进行富集后,用15 m L甲醇-乙酸乙酯混合淋洗液(4∶1)进行洗脱,浓缩,定容至1.0 m L后,用Kinetex XB-C18色谱柱以均含5.0mmol/L甲酸铵的甲醇-水为流动相梯度洗脱方式进行分离,电喷雾负离子模式(ESI-)电离,多重反应监测模式(MRM)以及内标法对6种PFCs进行定性定量测定。优化了固相萃取、色谱分离及质谱测定条件,考察了海水盐度对方法回收率的影响。在优化实验条件下,方法在2.0,5.0,10.0 ng/L加标水平下,实际海水样品的回收率为80.1%~117.4%,在2.0 ng/L加标水平的相对标准偏差(RSD,n=7)为8.2%~12.1%。6种PFCs的线性范围为0.5~50.0μg/L,相关系数大于0.999 0;方法的定量下限(LOQ,S/N=10)为0.5~1.5 ng/L。该方法具有样品前处理简单、分析速度快、选择性好的特点,适用于近岸及河口海水中全氟化合物的快速测定。     

Analysis of perfluorooctanesulfonate and related fluorochemicals in water and biological tissue samples by liquid chromatography-ion trap mass spectrometry

A method for the determination of perfluorinated compounds (PFCs) in various water and biological tissue samples was developed and validated. The contents of selected PFCs (i.e., perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA) and perfluorodecanoate (PFDA)) in water samples were extracted by the C(18) solid-phase extraction (SPE). The biological tissue samples (frozen-dried fish and oysters) were simply extracted by liquid-solid extraction with MTBE and adding tetrabutylammonium hydrogensulfate (TBA) as an ion-pairing reagent. The analytes were then identified and quantitated by liquid chromatography-ion trap negative electrospray mass spectrometry (LC-ESI ion-trap-MS). Limits of quantitation (LOQ) were established between 0.5 and 6 ng/l in 250 ml of water sample, while 5-50 ng/g (dry weight) for biological tissue sample. Intrabatch and interbatch precision with their accuracy at two concentration levels were also investigated. Precision for these three PFCs, as indicated by RSD, proved to be less than 11 and 17%, respectively. The total contents of PFOA, PFOS and PFDA were detected in concentrations of up to 400 ng/l in various water samples, while up to 1,100 ng/g in fish and oyster samples. PFOA and PFDA was the major PFCs detected in water samples and biological tissue samples, respectively.     

Determination of perfluorinated compounds in environmental water samples by high-performance liquid chromatography-electrospray tandem mass spectrometry using surfactant-coated Fe3O4 magnetic nanoparticles as adsorbents

A novel method was developed for solid-phase extraction (SPE) of perfluorinated compounds (PFCs) from environmental water samples using cetyltrimethylammonium bromide (CTAB) coated Fe₃O₄ nanoparticles (Fe₃O₄ NPs) as an adsorbent. The magnetic nanosized adsorbent has a large surface area and superparamagnetic properties. This gives it a high extraction capacity and allows for convenient isolation by a magnetic field. Compared with other SPE methods and our previous work on PFCs, this method exhibited a fairly good analytical performance and required a small amount of sorbent (50 mg) and short pretreatment times (30 min) for 800 mL environmental water samples. Seven PFCs, including perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), and perfluorotetradecanoic acid (PFTA), extracted by the optimized method were determined by high-performance liquid chromatography-electrospray tandem mass spectrometry (HPLC/ESI-MS/MS). A concentration factor of 1600 was achieved when extracting 800 mL of several environmental water samples. Detection limits obtained for PFOA, PFOS, PFNA, PFDA, PFUnDA, PFDoDA and PFTA were 0.14, 0.022, 0.31, 0.23, 0.11, 0.16, 0.091 ng/L, respectively. The relative standard deviations of recoveries ranged from 1 to 8%, indicating good method precision.     

Comparison of total fluorine, extractable organic fluorine and perfluorinated compounds in the blood of wild and pefluorooctanoate (PFOA)-exposed rats: Evidence for the presence of other organofluorine compounds

The widespread occurrence and environmental persistence of perfluorinated compounds (PFCs) received worldwide attention recently. Exhaustive analysis of all fluorinated compounds in an environmental sample can be daunting because of the constraints in the availability of analytical standards and extraction methods. Combustion ion chromatographic technique for trace fluorine analysis was used to assess the concentrations of known PFCs (e.g., PFOS, PFOA) and total fluorine (TF) in the blood of wild rats collected from Japan. The technique was further validated using tissues from PFOA-exposed rats. Six PFCs (PFOS, PFOSA, PFUnDA, PFDA, PFNA, and PFOA) were detected in all of the wild rat blood samples. Concentrations of extractable organic fluorine (EOF) in fraction 1 (Fr1; MTBE extraction) of wild rats ranged 60.9-134 ng F mL⁻¹, while those in fraction 2 (Fr2; hexane) were below LOQ (32 ng F mL⁻¹); TF concentrations in the blood of wild rats ranged from 59.9-192 ng F mL⁻¹. The contribution of known PFCs in EOF-Fr1 (MTBE) varied from 9% to 89% (56% on average), and known PFC concentrations in TF content were less than 25%. In contrast, TF concentrations in the blood of PFOA-exposed rats ranged from 46900 to 111000 ng F mL⁻¹, with PFOA contributing over 90% of TF. A comparison of results from the samples analyzed in this study and the literature revealed three distinct groups with PFOA/known PFC and TF levels (i.e., wild rats and general population, occupationally exposed workers, and PFOA-exposed laboratory rats). The mass balance analysis of the different forms of fluorine in blood suggested the presence of other forms of organic fluorine in addition to known PFCs.     

Determination of Perfluorochemicals in Human Milk Using Isotope‐dilution Liquid Chromatography Tandem Mass Spectrometry

A highly precise and accurate analytical method utilizing an isotope‐dilution liquid chromatography tandem mass spectrometry was developed and validated to determine two perfluorochemicals (PFCs): perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) in human milk samples. Identification of the analytes was confirmed under negative electrospray with multiple reaction monitoring (MRM) mode by the monitoring of one precursor ion and two product ions, and matching of relative ion intensities of the ions concerned in samples and calibration standards. Quantitation was based on the measurement of concentration ratios of the natural and labeled‐analogues in the samples and calibration mixtures. The isotope‐labeled internal standards were also used to correct the matrix effect and variations associated with the analysis. Intra‐ and inter‐day repeatabilities of replicate analyses of the PFOA and PFOS in milk samples were below 8%. The limit of quantitation was 2 pg/mL in a 5 mL milk sample. The PFOA and PFOS were detected in all 20 human milk samples at concentrations from 27.0 to 207 pg/mL. This is the first study to measure the occurrence of PFOA and PFOS in human milk from Taiwan.     

Determination of trace levels of total fluorine in water using combustion ion chromatography for fluorine: a mass balance approach to determine individual perfluorinated chemicals in water

Perfluorinated compounds (PFCs) such as perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) have received worldwide attention because of their environmental persistence and widespread distribution. Because of the lack of robust analytical methods and standards to detect all of the PFCs, and their precursors and metabolic intermediates, a mass balance approach involving the determination of total fluorine (TF), followed by fractionation of samples to separately determine inorganic and organic fluorine, is needed. In this study, we have developed a method to determine low microg/L levels of total fluorine (TF) in seawater samples. Further, seawater samples were fractionated into organic and inorganic fractions by extraction with organic solvents, which were then analyzed for TF, extractable organic fluorine (EOF) and inorganic fluorine (IF; i.e., fluoride). Concentrations of known perfluorinated compounds (PFCs) including PFOS and PFOA were also determined in water samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to enable calculation of the fraction of fluorine that is contributed by PFCs to TF. A major proportion of fluorine in seawater was in the form of fluoride (>90% in locations not affected by direct discharges). Nevertheless, within the organofluorine fraction, a major percentage (60-90%) of fluorine still remains unknown in water samples, suggesting the occurrence of other fluorinated acids in addition to known perfluorinated acids. Further studies are needed to identify and quantify the unidentified organofluorines in seawater. Mass balance analysis of total organic fluorine (TOF) and EOF is important, if we are to understand transport and fate of fluorinated compounds in the environment, and if we are to identify the sources of unidentified fluorinated compounds.     

Determination of perfluorooctanesulfonate and perfluorooctanoate in water samples by SPE-HPLC/electrospray ion trap mass spectrometry

Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) are the most notable members of an emerging class of persistent organic pollutants (POPs), perfluorochemicals (PFCs). A method for the determination of PFOS and PFOA in water samples was developed and validated in this study. Water samples collected from river and industrial effluent at Guangzhou, one of the most industrialized regions in China, were analyzed by solid-phase extraction (SPE) followed by high-performance liquid chromatography (HPLC) negative electrospray ionization (ESI) mass spectrometry. Operational parameters of the ion trap mass spectrometer were optimized to improve sensitivity and selectivity of this method. The limits of quantitation and recoveries were 2.0 ng L^− 1 and 75% for PFOA and 0.50 ng L^− 1 and 88% for PFOS, respectively. In river water samples, 2.3-33 ng L^− 1 of PFOS and < 2.0-11 ng L^− 1 of PFPA were detected. And sewage effluents contained considerably higher concentrations of PFOS and PFOA.     

Extraction of perfluorinated compounds from food matrices using fluorous solvent partitioning

Perfluorinated compounds (PFCs) such as perfluorooctane sulfonic acid (PFOS) have emerged as a new class of global environmental pollutant; they bioaccumulate and are persistent in the environment and in wildlife. Fluorine-fluorine interactions have been investigated as a means to isolate PFCs for mass spectrometric quantification. A novel sample extraction and cleanup procedure has been developed for fat-containing samples based on fluorous liquid-liquid extraction (F-LLE) in a triphasic solvent system consisting of hybrid:fluorous:organic solvent (trifluoroethanol:perfluorohexane/dichloromethane-saturated with water). This system partially separates fluorous from non-fluorous compounds, allowing removal of co-extractants, which had previously resulted in liquid chromatography mass spectrometry (LC-MS/MS) peak suppression preventing low-level detection of PFCs. The developed F-LLE was coupled with an existing extraction protocol allowing the limits of detection of PFCs to be lowered an order of magnitude for high fat samples. The developed workflow was used to show the absence of a range of eleven PFCs in nine UK and one Irish cheese samples. This representative application demonstrates a new application of fluorous-organic extraction in sample cleanup for measurement of fluorinated analytes in food, environment and broader analytical chemistry.     

Determination of perfluorinated compounds in wastewater and river water samples by mixed hemimicelle-based solid-phase extraction before liquid chromatography-electrospray tandem mass spectrometry detection

A comparative study on the use of cetyltrimethylammonium bromide (CTAB)-coated silica and sodium dodecyl sulphate (SDS)-coated alumina mixed hemimicelles-based solid-phase extraction (SPE) for the pre-concentration of six perfluorinated compounds (PFCs) in environmental water samples was presented. The six analytes heptafluorobutyric acid (HFBA), perfluoroheptanic acid (PFHeA), perfluorooctanic acid (PFOA), perfluorooctanic sulfonic (PFOS), perfluorononanic acid (PFNA) and perfluorodecanic acid (PFDeA) were quantitatively retained on both sorbent materials. The cationic surfactant (CTAB adsorbed onto silica) was more appropriate for SPE of PFCs. The main factors affecting adsolubilization of PFCs including the amount of surfactant, pH of solution, sample loading volume and desorption were investigated and optimized. Concentration factor of 500 were achieved by SPE of 500 mL of several environmental water samples. The method detection limits obtained for HFBA, PFHeA, PFOA, PFOS, PFNA and PFDeA were 0.10, 0.28, 0.07, 0.20, 0.10 and 0.05 ng/L, respectively. The relative standard deviation of recoveries ranged from 2 to 8%, which indicated good method precision.     

Development and validation of a pressurized liquid extraction liquid chromatography–tandem mass spectrometry method for perfluorinated compounds determination in fish

This paper describes the development and validation of an analytical methodology to determine eight perfluorinated compounds (PFCs) in edible fish using pressurized liquid extraction (PLE) with water and solid-phase extraction (SPE) with an ion-exchanger as extraction and pre-concentration procedures, followed by liquid chromatography–quadrupole-linear ion trap mass spectrometry (LC–QqLIT–MS). The rapidity and effectiveness of the proposed extraction procedure were compared with those most commonly used to isolate PFCs from fish (ion-pairing and alkaline digestion). The average recoveries of the different fish samples, spiked with the eight PFCs at three levels (the LOQ, 10 and 100 μg kg⁻¹ of each PFC), were always higher than 85% with relative standard deviation (RSD) lower than 17%. A good linearity was established for the eight PFCs in the range from 0.003–0.05 to 100 μg kg⁻¹, with r > 0.9994. The limits of quantification (LOQs) were between 0.003 and 0.05 μg kg⁻¹, which are well below those previously reported for this type of samples. Compared with previous methods, sample preparation time and/or LOQs are reduced. The method demonstrated its successful application for the analysis of different parts of several fish species. Most of the samples tested positive, mainly for perfluoropentanoic acid (PFPA), perfluorobutane sulfonate (PFBS) and perfluorooctanoic acid (PFOA) but other of the eight studied PFCs were also present.