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.     

高效液相色谱-串联质谱法对奶粉、酸奶中全氟化合物的分析

建立了液相色谱-质谱检测奶粉和酸奶中11种全氟化合物(PFCs)的分析方法.分别考察了溶液离子强度和酸碱度对固相萃取效率的影响,结果表明,0.5 ～12.5 mmol/L NaCl溶液的影响很小,且中性和微酸性条件下回收率较好.通过优化和比较,选用等体积的甲醇和0.01 mol/L盐酸的甲醇溶液依次对奶粉中的PFCs进行萃取,对于酸奶则使用甲醇直接萃取,并用WAX柱对萃取液净化.以甲醇(A)和50 mmol/L 醋酸铵(B)为流动相进行梯度洗脱,洗脱时间为10 min(或15 min),流速1 mL/min.内标法定量,奶粉和酸奶中11种PFCs的加标回收率分别为81% ～111%和80% ～118%,方法检出限为2 ～29 ng/L.用该方法对市售国产和进口奶粉及酸奶样品中的PFCs进行了分析.     

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%。     

碳纳米管复合材料结合分散固相萃取-高效液相色谱-串联质谱法检测环境水样中痕量全氟化合物

以碳纳米管-二氧化硅棒复合材料为吸附剂,基于分散固相萃取法和液相色谱-串联质谱法建立了一种高灵敏、快速分析环境水样中痕量全氟化合物(PFCs)的方法。该研究选择全氟己烷磺酸、全氟庚酸、全氟辛酸、全氟辛烷磺酸、全氟壬酸和全氟癸酸6种全氟化合物为目标分析物。采用单因素优化法对影响萃取效果的重要因素进行了优化。获得的最佳条件为：吸附时间为30 min、吸附剂用量为10 mg、样品溶液pH为6、萃取过程添加NaCl浓度为1.7 mol/L、解吸溶剂为丙酮、解吸时间为4 min、解吸液的体积为4 mL。采用高效液相色谱-三重四极杆质谱联用技术对水样品中全氟化合物进行定量分析。以5 mmol/L乙酸铵和甲醇为流动相进行梯度洗脱,经Kinetex C18色谱柱(100 mm×2.1 mm, 1.7μm)分离,采用电喷雾离子源、负离子扫描模式和质谱多反应监测,实现了环境水样中6种全氟化合物的快速定性和定量分析。在优化条件下,6种全氟化合物在各自的线性范围内线性关系良好,检出限(S/N=3)为0.10～0.26 ng/L。添加500 ng/L 6种PFCs进行重复性实验,日内相对标准偏差(RSD)为2....     

加速溶剂萃取-高效液相色谱-串联质谱法测定空气中的全氟化合物

建立了加速溶剂萃取-高效液相色谱-串联质谱法(ASE-HPLC-MS/MS)测定环境空气样品中全氟化合物(PFCs)的分析方法。采用PS-1型大流量采样器采集环境空气样品,聚氨酯(PUF)收集空气,石英纤维滤膜(QFF)收集空气颗粒物。采用ASE萃取采样后的PUFs和QFFs,萃取剂为甲醇-丙酮(1∶1,V/V),萃取温度100℃,萃取压力15MPa,静态萃取时间15min,连续萃取3次。萃取液经K-D浓缩后转换溶剂为甲醇,采用HPLC-MS/MS测定PFCs的含量。线性范围在0.1～50μg/L之间,方法检出限在0.034～0.54pg/m3范围。应用本方法检测2007年5～6月在广州市采集的环境空气样品,蒸气态PFCs的总含量在5.2～37.4pg/m3范围内,颗粒态PFCs的总含量在11.3～74.3pg/m3范围内。本方法适用于监测环境空气中的痕量PFCs。     

固相萃取-液相色谱-串联质谱法同时测定水中14种短链和长链全氟化合物

建立了固相萃取-超高压液相色谱-三重四极杆质谱同时测定水中14种短链和长链全氟化合物（PFCs）的方法。水样经WAX混合型固相萃取小柱富集和净化后,采用BEH C18色谱柱、甲醇和5 mmol/L乙酸铵水溶液作为流动相进行梯度洗脱,质谱采用多反应监测模式,内标法定量分析。14种PFCs在0.1~50 μg/L范围内线性关系良好,相关系数大于0.99,方法检出限和定量限分别为0.09~1.15 ng/L和0.29~3.85 ng/L。在2、10和20 ng/L加标水平下,8种PFCs的平均回收率为85.0%、120.2%和117.4%,平均相对标准偏差为9.2%、9.0%和6.6%,6种PFCs的回收率相对较低,主要由于其在瓶/管壁上的吸附作用导致。应用本方法分析某淡水湖水样,检出4种短链和5种长链PFCs,质量浓度为41.29~49.05 ng/L和98.43~111.02 ng/L。结果表明该方法适用于对环境水体中短链和长链PFCs的同时分析测定。     

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。     

分散固相萃取结合HPLC-MS/MS检测鸡蛋中16种全氟化合物

建立了分散固相萃取净化结合HPLC-MS/MS测定鸡蛋中16种全氟化合物(Perfluorinated compounds,PFCs)的方法。样品经乙腈40℃下超声萃取,氮吹浓缩,石墨化碳黑分散萃取净化后,采用HPLCMS/MS进行测定,基质曲线-内标法定量。结果显示,16种PFCs在0.50~10.0μg/L浓度范围内呈良好线性,相关系数(r)为0.996 2~0.999 9,检出限为0.001~0.093μg/kg,定量下限为0.003~0.310μg/kg。在0.5,1.0,2.0μg/kg 3个加标浓度水平下,16种PFCs的加标回收率为79%~125%,相对标准偏差(RSDs,n=6)为0.26%~14%。该方法具有净化效果好、定量准确、灵敏度高的特点,适用于鸡蛋样品中16种常见全氟化合物的快速确认和准确定量。     

超高效液相色谱-串联质谱法测定人尿液中全氟有机化合物

采用超高效液相色谱-串联质谱(UPLC-MS/MS)联用技术,建立了对人尿液中12种全氟有机化合物(PFCs)的分析方法。首先在尿液样品中加入相应的同位素内标,以2%(体积分数)甲酸甲醇溶液超声萃取、离心后,将提取液用弱阴离子交换固相萃取柱净化,采用UPLC-MS/MS测定,内标法定量。12种目标化合物在0.05～50 μg/L质量浓度范围内线性良好,相关系数(r)均大于0.992,检出限在0.44～3.47 ng/L之间。在20、100、500 ng/L添加水平下,平均回收率范围为80.3%～116.2%,相对标准偏差(n=6)在5.5%～13.8%之间。该方法灵敏度高、重现性好、回收率高、操作简单,适合人尿液中PFCs的测定。     

典型全氟有机酸类化合物的样品前处理与分析方法研究进展

全氟辛烷磺酸（PFOS）和全氟辛烷羧酸（PFOA）是两种典型的全氟有机酸类化合物,也是全氟化合物（PFCs）前体物的最终降解产物,具有肝毒性、胚胎毒性、生殖毒性、神经毒性,检出率最高。在各种被污染的介质中,PFOS和PFOA含量往往很低,基体复杂多样,快速高效的样品前处理技术成为测定的关键环节。目前,国际上对PFOS和PFOA的测定无统一标准,而我国关于PFCs的分析研究落后于国际发展水平。该文介绍了PFOS和PFOA的特性,系统总结和评述了前处理技术（液液萃取、固相萃取、固相微萃取、超声萃取和QuEChERS法）及分析方法（色谱-质谱方法、光谱法、酶联免疫法和电化学法）,以期为PFOS和PFOA的分析监测及标准制定提供参考。     

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.     

Tetrahydrofuran–water extraction,in-line clean-up and selective liquid chromatography/tandem mass spectrometry for the quantitation of perfluorinated compounds in food at the low picogram per gram level

A new solvent extraction system was developed for extraction of PFCs from food. The extraction is carried out with 75:25 (v/v) tetrahydrofuran:water, a solvent mixture that provides an appropriate balance of hydrogen bonding, dispersion and dipole–dipole interactions to efficiently extract PFCs with chains containing 4–14 carbon atoms from foods. This mixture provided recoveries above 85% from foods including vegetables, fruits, fish, meat and bread; and above 75% from cheese. Clean-up with a weak anion exchange resin and Envi-carb SPE, which were coupled in line for simplicity, was found to minimize matrix effects (viz. enhancement or suppression of electrospray ionization). The target analytes (PFCs) were resolved on a perfluorooctyl phase column that proved effective in separating mass interferences for perfluorooctane sulfonate (PFOS) in fish and meat samples. The mass spectrometer was operated in the negative electrospray ionization mode and used to record two transitions per analyte and one per mass-labeled method internal standard. The target PFCs were quantified from solvent based calibration curves. The limits of detection (LODs) were as low as 1–5 pg analyte g⁻¹ food; by exception, those for C₄ and C₅ PFCs were somewhat higher (25–30 pg g⁻¹) owing to their less favourable mass response. To the best of our knowledge these are among the best LODs for PFCs in foods reported to date. The analysis of a variety of foods revealed contamination with PFCs at levels from 4.5 to 75 pg g⁻¹ in 25% of samples (fish and packaged spinach). C₁₀–C₁₄ PFCs were found in fish, which testifies to the need to control long-chain PFCs in this type of food. The proposed method is a useful tool for the development of a large-scale database for the presence of PFCs in foods.     

HPLC-MS/MS与ICP-MS分别测定血液中14种全氟化合物及常见金属元素

为了解广东儿童血液中全氟化合物(PFCs)和常见金属元素的含量水平,为儿童健康评估提供数据,该文采用蛋白沉淀法提取样品,高效液相色谱-串联质谱(HPLC-MS/MS)检测样品中14种PFCs。同时,以石墨全自动消解仪消解血液样品,电感耦合等离子体质谱(ICP-MS)检测血液中钙(Ca)、镁(Mg)、铁(Fe)、锌(Zn)、铜(Cu)和锰(Mn)元素。结果显示,儿童血液中14种PFCs被普遍检出,其中全氟辛基磺酸(PFOS)和全氟辛基羧酸(PFOA)的检出率及浓度最高,但在一些个体中发现较高浓度的其它碳链PFCs。PFCs浓度有随着年龄增长而下降的趋势,但除了全氟丁基磺酸外,无性别差异。另一方面,儿童血液中检出的Ca、Mg、Fe、Zn、Cu和Mn含量在正常范围内,未发现有性别差异。研究显示PFCs普遍存在儿童血液中,儿童PFCs暴露水平的研究应引起重视。在今后的监测中,不仅要关注PFOS和PFOA,也要关注其它碳链PFCs。     

环境水样及固相样品中全氟化合物分析方法研究进展

全氟化合物(Perfluorinated compounds,PFCs)是一类持久性有机污染物,在环境中普遍检出,严重危害人体健康,已成为环境科学和毒理学研究的热点之一.PFCs含有较多同系物及同分异构体,且在环境中通常为痕量水平(ng/g或μg/L),迫切需要建立灵敏可靠的样品前处理和检测技术.国内外已针对环境样品基质中痕量PFCs的检测开展了大量研究,但有关复杂环境样品中PFCs前处理方法、分析方法、基质效应等方面的系统评述还相对较少.本文综述了环境样品(水、沉积物/污泥、土壤、植物)中PFCs的前处理方法、检测方法(尤其是同分异构体)及环境样品基质效应对其检测的影响,以期为相关研究提供参考.     

Analysis of perfluorinated chemicals in sludge: Method development and initial results

A fast, rigorous method was developed to maximize the extraction efficacy for ten perfluorocarboxylic acids and perfluorooctanesulfonate from waste-water-treatment sludge and to quantitate using liquid chromatography, tandem-mass spectrometry (LC/MS/MS). First, organic solvents were tested for extraction efficiency, including acetonitrile (ACN), methanol (MeOH), isopropanol (IPA), tetrahydrofuran (THF), and 50/50 ACN/MeOH (v/v). Among the extractants tested, 50/50 ACN/MeOH yielded the best results for our combined criteria of extraction efficacy and solvent-handling convenience. Second, chemical pretreatment prior to solvent extraction was tested with sodium hydroxide (NaOH), potassium hydroxide (KOH), hydrochloric acid (HCl), and potassium persulfate (K₂S₂O₈). Pretreatment with NaOH and HCl effectively recovered additional PFCs from the sludge, but KOH and K₂S₂O₈ digestion were less effective than no pretreatment. Third, cleanup methods were investigated with solid-phase extraction using HLB (hydrophilic–lipophilic balanced) and WAX (weak-anion exchange) stationary phases, and with ion-pairing. The HLB stationary phase yielded a slight edge over the other two cleanup strategies in terms of recoverable PFCs and chromatographic separation. Finally, the appropriateness of isotopically labeled PFCs for quantitating unlabeled PFCs using isotopic dilution in complex sludge extracts was evaluated by comparison to results obtained with the standard-addition method. A National Institute of Standards and Technology (NIST) domestic sludge (CRM 2781) was analyzed using our finalized method and compared with previously reported results.     

聚酰胺固相萃取-超高效液相色谱-串联质谱法同时检测饲料中的6种全氟化合物

建立了饲料中6种全氟化合物的聚酰胺固相萃取-超高效液相色谱-串联四极杆质谱分析法。样品采用酸化乙腈提取,在酸性条件下用聚酰胺固相萃取小柱富集,甲醇淋洗净化,5%（v/v）氨水/甲醇溶液洗脱后采用超高效液相色谱-串联四极杆质谱（UPLC-MS/MS）检测。分析柱为Acquity BEH C₁₈（100 mm×2.1 mm,1.7 μm）;流动相为5 mmol/L乙酸铵-乙腈梯度洗脱;在最佳实验条件下,采用多反应监测负离子模式测定,同位素内标法定量。该方法对6种全氟化合物的检出限均小于0.1 μg/kg;对6种饲料及原料的加标回收率为94.2%~108.9%,精密度（RSD）为1.8%~8.6%（n=6）;在0.5~25 μg/L范围内均呈良好的线性关系,线性回归系数r>0.995。该方法前处理成本低,效果好,适合复杂基质样品的检测。     

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.     

Analysis of perfluorinated compounds in sewage sludge by pressurized solvent extraction followed by liquid chromatography-mass spectrometry

Perfluorinated compounds (PFCs) are widely used in everyday life and one of the main recipients of these compounds is waste water treatment plants (WWTPs). Due to the structure and physicochemical properties of PFCs, these compounds could be redistributed from influent water to sludge. This work reports a new validated protocol for the analysis of 13 perfluorinated acids, 4 perfluorosulfonates and the perfluorooctanesulfonamide. The present work has been focused to develop a sensitive and robust method for the analysis of 18 PFCs in sewage sludge, based on pressurized solvent extraction (PSE) followed by solid phase extraction (SPE) clean-up, analytes separation by liquid chromatography and analysis in a hybrid quadrupole-linear ion trap mass spectrometer (LC-QLiT-MS/MS) working in single reaction monitoring (SRM) mode. The final methodology was validated using a blank sewage sludge fortified at different concentration levels. The method limits of detection were ranging in general from 15 to 79 ng/kg. These values were comparable to the decision limit (CCα) and the detection capability (CCβ), which were 17-1134 ng/kg and 18-1347 ng/kg, respectively. The percentage of recovery was from 79 to 111% in the most cases at different spiked levels. Finally, the repeatability of the method was in the range 4% (PFOS and PFOA) to 25% (RSD %). In order to evaluate the applicability of the method, 5 sludge samples were analyzed. The results showed that the 18 PFCs were present in all samples. However, the concentrations for most of them were below the limits of quantification. The compound present at higher concentrations was perfluorooctanesulfonate (PFOS), which was in concentrations from 53.0 to 121.1 μg/kg. The other PFCs were at concentrations between 0.3 and 30.3 μg/kg.