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。     

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。     

气相色谱-三重四极杆质谱法同时测定纺织品中11种挥发性全氟化合物前体物

以甲醇为提取溶剂,超声辅助提取纺织品中的全氟化合物前体物,建立了一种气相色谱-三重四极杆质谱(GC-MS/MS)法同时测定纺织品中11种挥发性全氟化合物前体物:4种氟调聚物醇(FTOHs)、3种氟调聚丙烯酸酯(FTAs)、2种全氟辛基磺酰胺(FOSAs)和2种全氟辛基磺酰胺乙醇(FOSEs)。考察了超声提取溶剂、提取温度和提取时间对提取效率的影响,最终确定用甲醇为提取溶剂,70 ℃下超声提取60 min,目标物经VF-WAXms毛细管柱(30 m×0.25 mm×0.25 μm)程序升温分离,GC-MS/MS多反应监测(MRM)模式检测,外标法定量。实验结果表明:11种挥发性全氟化合物前体物在10~500 μg/L范围内线性关系良好,相关系数(r)均不低于0.9984;以信噪比为3计算,检出限(LOD)为0.002~0.04 mg/kg;以信噪比为10计算,定量限(LOQ)为0.006~0.1 mg/kg;不同材质纺织品中,11种挥发性全氟化合物前体物在高、中、低3个添加水平下的回收率为73.2%~117.2%,相对标准偏差(RSD)为0.1%~9.4%(n=6)。该方法前处理简单,定性、定量准确,灵敏度高,重现性好,可有效用于纺织品中11种挥发性全氟化合物前体物的同时检测。实际样品分析发现,当前全氟化合物前体物已被应用于纺织品整理当中。该方法的建立对我国纺织品中全氟化合物前体物风险物质的管控和检测标准的制定具有一定的理论和现实意义。     

Fast sample preparation involving MASE and coupled column normal phase liquid chromatography for the rapid trace analysis of dioxins in air-dust samples from fire catastrophe emissions

A new approach has been developed and tested for the urgent analysis of dioxins in samples of air-dust filters originating from catastrophe emissions. The procedure consists of a fast extraction of the sample with microwave solvent extraction (MASE) and acetone as solvent followed by a fast cleanup of the extract with normal phase coupled column liquid chromatography (LC/LC).

The multi-dimensional LC/LC system employs a 50 mm×4.6 mm i.d. column packed with 3 μm silica and a 150 mm×4.6 mm i.d. column packed with 5 μm PYE as the first and second analytical column, respectively. Iso-hexane is used on both columns to perform cleanup and dichloromethane to perform efficient back-flush elution of the compounds from the second column. The obtained polarity-based separation in the first dimension and molecular-structure based separation in the second dimension provides a fast and powerful cleanup.

Validation was done by analysing samples of homemade RIVM air-dust with aged residues (n=8, spiking level about 15 pg mg⁻¹ per compound) of dioxins/furans and samples of reference Urban Dust SRM 1649a (n=4) with both the new approach and the existing conventional procedure and were instrumentally analyzed with capillary gas chromatography and high resolution mass spectrometric detection (GC/HRMS).

In comparison to the existing conventional procedure, the new approach reduces sample processing from several days to several hours per sample.

As regards the aged-residue air-dust samples, the new method shows a good accuracy, precision and high selectivity providing a performance in good agreement with the existing procedure. In SRM air-dust, the concentration of a few compounds obtained by the new method was below (10–50%) the certified value.     

凝固漂浮有机液滴-分散液液微萃取-高效液相色谱-串联质谱法测定海水中苯并三唑类紫外线过滤剂

建立了海水中7种苯并三唑类紫外线过滤剂的凝固漂浮有机液滴-分散液液微萃取-高效液相色谱-串联质谱分析方法。优化后的萃取实验条件：20 μL十二醇为萃取溶剂,400 μL甲醇为分散溶剂,NaCl质量分数为8%,pH小于6,涡旋振荡时间2 min。目标化合物经Hypersil GOLD色谱柱（150 mm×2.1 mm,5 μm）结合甲醇-水梯度洗脱分离后,用正离子多反应监测模式进行质谱分析。在较宽的线性范围内,7种化合物的线性相关系数（r²）均大于0.99;基质加标回收率为68.3%~127.5%,相对标准偏差为0.9%~15.2%,方法的检出限为0.001~0.090 μg/L,定量限为0.003~0.300 μg/L。将建立的方法用于大连8个海滨浴场海水中苯并三唑类紫外线过滤剂的测定,部分浴场海水有不同程度的检出。该方法简便、快速、环境友好、灵敏度高,可用于海水中苯并三唑类紫外线过滤剂的分析检测。     

分散固相萃取-液相色谱-串联质谱法测定淡水鱼中柱孢藻毒素、节球藻毒素和微囊藻毒素

建立了同时检测淡水鱼中柱孢藻毒素、节球藻毒素、微囊藻毒素-RR、微囊藻毒素-YR及微囊藻毒素-LR的分散固相萃取-液相色谱-串联质谱方法。样品粉碎后，用乙腈-水-甲酸（89 ∶ 10 ∶ 1，v/v/v）提取目标物，C₁₈分散固相萃取柱净化，Agilent ZORBAX Eclipse XDB C₁₈色谱柱分离，乙腈和水梯度洗脱，在多反应监测（MRM）模式下进行定性分析，基质匹配标准曲线外标法定量。考察了提取溶剂及吸附剂种类对提取效率和净化效果的影响，并优化了液相色谱-串联质谱条件。该法在各自范围内具有良好线性关系，相关系数（R²）≥0.9954；检出限为5~10 μg/kg，定量限为15~40 μg/kg；样品的加标回收率为62.3%~101.2%。该方法前处理方法简单快速，灵敏高效，适用于淡水鱼中柱孢藻毒素、节球藻毒素和微囊藻毒素的有效检测。     

Dispersive liquid–liquid microextraction with little solvent consumption combined with gas chromatography–mass spectrometry for the pretreatment of organochlorine pesticides in aqueous samples

Dispersive liquid–liquid microextraction with little solvent consumption (DLLME-LSC), a novel dispersive liquid–liquid microextraction (DLLME) technique with few solvent requirements (13 μL of a binary mixture of disperser solvent and extraction solvent in the ratio of 6:4) and short extraction time (90 s), has been developed for extraction of organochlorine pesticides (OCPs) from water samples prior to gas chromatography/mass spectrometry analysis. In DLLME-LSC, much less volume of organic solvent is used as compared to DLLME. The new technique is less harmful to environment and yields a higher enrichment factor (1885–2648-fold in this study). Fine organic droplets were formed in the sample solution by manually shaking the test tube containing the mixture of sample solution and extraction solvent. The large surface area of the organic solvent droplets increases the rate of mass transfer from the water sample to the extractant and produces efficient extraction in a short period of time. DLLME-LSC shows good repeatability (RSD: 4.1–9.7% for reservoir water; 5.6–8.9% for river water) and high sensitivity (limits of detection: 0.8–2.5 ng/L for reservoir water; 0.4–1.3 ng/L for river water). The method can be used on various water samples (river water, tap water, sea water and reservoir water). It can be used for routine work for the investigation of OCPs.     

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。     

Ion-pair sorptive extraction of perfluorinated compounds from water with low-cost polymeric materials: Polyethersulfone vs polydimethylsiloxane

A method for the determination of seven perfluorinated carboxylic acids and perfluorooctane sulphonate (PFOS) in aqueous samples using low-cost polymeric sorptive extraction as sample preparation technique, followed by liquid chromatography–tandem mass spectrometry (LC–MS/MS) determination has been developed and validated. Simplicity of the analytical procedure, low volume of solvent and sample required, low global price and a good selectivity providing cleaner extracts are the main advantages of this extraction technique. Polydimethylsiloxane (PDMS) and polyethersulfone (PES) materials were evaluated and compared to achieve the best extraction efficiencies. Hence, different variables have been optimized, viz.: sample pH, concentration of an ion-pairing agent (tetrabutylammonium), ionic strength, sample volume, extraction time, desorption solvent volume, desorption time and the need for auxiliary desorption techniques (sonication). Overall, PES leaded to a better sensitivity than PDMS, particularly for the most polar compounds, reaching detection limits (LODs) in the 0.2–20 ng L⁻¹ range. The precision of the method, expressed as relative standard deviation (RSD), was lower than 16%. Finally, the PES material was employed for the analysis of sea, sewage and fresh water samples. Perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) were detected in all the analyzed influent samples reaching levels of up to 401 ng L⁻¹. In surface water, perfluorohexanoic acid (PFHxA) exhibited the highest concentrations, up to 137 ng L⁻¹.     

Liquid chromatographic determination of St. John's wort components in functional foods

A method was developed for determination of St. John's wort marker compounds hypericin, pseudohypericin, hyperforin, and adhyperforin in functional foods. Solid-phase extraction provided analyte extraction and significant sample cleanup prior to analysis using liquid chromatography (LC) with UV and fluorescence detection. In addition to quantification using LC-UV, confirmation was made with electrospray ionization LC mass spectrometry (LC/MS). Several commercially available tea and drink products claiming to contain St. John's wort were tested. Recoveries ranged from 51 to 98% for the liquid samples. Comparison of the concentrations in 4 St. John's wort teas showed a variation in analyte concentration (1044-10 ng/mL marker compounds in brewed tea) and composition. No marker compounds were found in the beverages, indicating possible decomposition of the marker compounds caused by low pH and/or exposure to light. A solvent extraction procedure was developed for analysis of the marker compounds from solid samples. Analytes were detected at low parts per million, with an average recovery of 75%. No St. John's wort components were found in the 2 solid functional food samples analyzed.     

Decyl‐perfluorinated magnetic mesoporous microspheres for extraction and analysis perfluorinated compounds in water using ultrahigh‐performance liquid chromatography–mass spectrometry

In this work, the interior‐walls decyl‐perfluorinated functionalized magnetic mesoporous microspheres (F₁₇–Fe₃O₄@mSiO₂) were synthesized for the first time, and applied as adsorbents to extract and concentrate perfluorinated compounds (PFCs) from water samples. The fluorous functionalized interior pore‐walls contributed to the high‐selective preconcentration of PFCs due to fluorous affinity; and abundant silanol groups on the exterior surface of microspheres contributed to the good dispersibility in water sample. Four kinds of PFCs were selected as model analytes, including perfluorooctanoic acid, perfluorononanoic acid, perfluorododecanoic acid, and perfluorooctane sulphonate. In addition, UHPLC‐ESI/MS/MS was introduced to the fast and sensitive detection of the analytes after sample pretreatment. Important parameters of the extraction procedure were optimized, including salinity, eluting solvent, the amount of F₁₇–Fe₃O₄@mSiO₂ microspheres, and extraction time. The optimized procedure took only 10 min to extract analytes with high recoveries and merely 800‐μL acetonitrile to elute analytes from the magnetic adsorbents. Validation experiments showed good linearity (0.994–0.998), precision (2.6–7.6%), high recovery (93.4–105.7%) of the proposed method, and the limits of detection were from 0.008 to 0.125 μg/L. The F₁₇–Fe₃O₄@mSiO₂ magnetic microspheres have the advantages of great dispersibility in aqueous solution, high specificity of extraction, large surface area, and efficient separation ability. The results showed that the proposed method based on F₁₇–Fe₃O₄@mSiO₂ microspheres is a simple, fast, and sensitive tool for the analysis of PFCs in water sample.     

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.     

气相色谱-电子捕获检测法测定海水中十氯酮残留

通过考察提取溶剂、毛细管柱、净化条件及共溶出干扰物等因素对十氯酮测定的影响,建立了二氯甲烷液-液富集萃取、硫酸净化分离、气相色谱法(GC)-电子捕获检测器(ECD)测定海水介质中有机氯农药类持久性有机污染物十氯酮残留分析方法。1 L海水经50 mL二氯甲烷萃取富集,浓缩后采用硫酸净化,以1%(体积分数)甲醇/正己烷混合溶液转移定容后,采用DB-5非极性毛细管柱进行GC分离,电子捕获检测器可测定其中十氯酮的含量;该方法采用外标法定量,在5～100 μg/L范围内呈线性,线性相关系数为0.9989。低、中、高3个浓度水平的平均加标回收率为81%～108%,相对标准偏差为1.2%～5.1%(n=6)。方法的检出限为0.6 ng/L。结果表明,该方法灵敏度高,线性关系好,可以满足简便、快速、准确测定海水中十氯酮的要求。     

顶空气相色谱-质谱联用技术的应用进展

顶空分析作为一种无有机溶剂萃取的样品处理技术,通常与气相色谱-质谱（GC-MS）技术结合用来分析复杂基质中的挥发性有机物。顶空气相色谱-质谱（HS-GC-MS）技术具有快速、高效、环保、灵敏度高等特点,在常规分析中发挥着重要作用。该文简要概述了静态顶空、动态顶空、顶空固相微萃取分析以及GC-MS联用技术,并介绍了整个顶空分析系统的影响因素和优化过程。根据基质类型的分类,综述了HS-GC-MS在食品和饮料、环境、生物等样品中的应用实例。HS-GC-MS的研究非常活跃,不断出现新应用,在分析挥发性有机物方面具有广阔前景。     

Reverse fluorous solid-phase extraction: a new technique for rapid separation of fluorous compounds

Fluorous-tagged compounds can rapidly be separated from organic (non-tagged) compounds by the new separation technique of reverse fluorous solid-phase extraction (r-fspe). In a reversal of the roles of solid and liquid phases in standard fluorous spe, a mixture is charged to a polar solid phase (standard silica gel) and then eluted with a fluorous solvent or solvent mixture. The organic components of the mixture are retained, while the fluorous components pass. [structure: see text]     

Development and validation of an analytical method for the simultaneous determination of cocaine and its main metabolite, benzoylecgonine, in human hair by gas chromatography/mass spectrometry

A new, simple and rapid procedure has been developed and validated for the determination of cocaine and its main metabolite, benzoylecgonine, in human hair samples. After extraction from within the hair matrix by a mixture of methanol/hydrochloric acid (2:1) at 65 degrees C for 3 h, and sample cleanup by mixed-mode solid-phase extraction (SPE), the extracts were analyzed by gas chromatography/mass spectrometry (GC/MS), after derivatization with N-methyl-N-(trimethylsilyl)trifluoroacetamide with 5% chlorotrimethylsilane. Using a sample size of only 20 mg of hair, limits of detection (LODs) and quantitation (LOQs) were, respectively, 20 and 50 pg/mg for cocaine, and 15 and 50 pg/mg for benzoylecgonine, achieving the cut-off values proposed by the Society of Hair Testing for the analysis of these compounds in hair. The method was found to be linear (weighing factor of 1/x) between the LOQ and 20 ng/mg for both compounds, with correlation coefficients ranging from 0.9974 to 0.9996 for cocaine; and from 0.9981 to 0.9994 for benzoylecgonine. Intra- and interday precision and accuracy were in conformity with the criteria normally accepted in bioanalytical method validation. The sample cleanup step presented a mean absolute recovery greater than 90% for both compounds. The developed method may be useful in forensic toxicology laboratories for the analysis of cocaine and benzoylecgonine in hair samples, taking into account its speed (only 3 h are required for the extraction of the analytes from within the matrix, whereas 5 h or even overnight extractions have been reported) and the low limits achieved (using a single quadrupole mass spectrometer, which is available in most laboratories).     

Perfluorinated compounds (PFCs) in groundwater and aqueous soil extracts: using inline SPE-LC-MS/MS for screening and sorption characterisation of perfluorooctane sulphonate and related compounds

Perfluorinated compounds (PFCs) have been recognised as emerging pollutants of global relevance. A fully automated method with inline solid-phase extraction coupled to electrospray ionisation liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) is presented and used for characterisation of soil adsorption and desorption for six PFCs: perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorobutane sulphonate (PFBS), and perfluorooctane sulphonate (PFOS). The method reduces sample turnaround time and solvent consumption and is suitable for low volume sampling. The only sample preparation necessary for water samples was sedimentation by centrifugation. The method has a total runtime of 21 min including inline sample cleanup (2 min for injection and SPE, 14 min for the chromatographic separation, 5 min for reconditioning). Negative AP-ESI with selective reaction monitoring (SRM) was used and the method was documented for quantification of the six environmentally important PFCs in subsoil matrix and related aqueous matrixes (groundwater and drainage water). Linearity was demonstrated in the range 5 to 2,500 ng/l and the LOD was between 2 and 8 ng/l in groundwater. Adsorption was characterised by linear Freundlich isotherms for all six compounds in two agricultural top soils (A horizon, sandy and clayey soil).Variability in sorption characteristics for soil types as well as compound properties were found, and correlation between the organic carbon normalised sorption coefficient (K _OC) and PFC molecular weight was demonstrated. The K _d values were in the range 0.1 to 33 (l/kg), and 0.3 to 65 (l/kg) for sorption and desorption respectively.     

Quantitative detection of trace perfluorinated compounds in environmental water samples by Matrix-assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry with 1,8-bis(tetramethylguanidino)-naphthalene as matrix

Determination of perfluorinated compounds (PFCs) is very important because of their potential hazards to the environment and human health. In present work, 1,8-bis (tetramethylguanidino)-naphthalene (TMGN), a superbasic proton sponge, was firstly employed as the matrix for quantitative detection of acidic PFCs in environmental water samples by Matrix-assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF-MS). Several acidic PFCs, such as perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), were selected as model analytes for demonstrating the feasibility of the detection method. The results showed that deprotonated ions of these PFCs were detected without any other matrix ions interference. The achieved sensitivity with TMGN for PFOS detection was ten-fold higher than that with 1,8-bis (dimethyl-amino)-naphthalene (DMAN) which was used for the detection of fatty acid by MALDI-TOF-MS. The high sensitivity of this method made it feasible to monitor and quantify acidic PFCs in complicated environmental water samples. Furthermore, a novel combined strategy of solid phase extraction (SPE) followed by MALDI-TOF-MS detection was developed for quantifying PFCs in environmental water samples. The calibration curves with a wide linear dynamic range (0.1-10 ng L⁻¹ for PFOS, PFHxS, and PFBS, and 0.5-50 ng L⁻¹ for PFOA, PFNA, and PFDA.) were obtained. The limit of detection (LOD) for PFOS of this method was 0.015 ng L⁻¹ (a signal-to-noise ratio of 3), which was lower than the LOD (0.036 ng L⁻¹) obtained by high-pressure liquid chromatography/tandem mass spectrometry (LC-MS/MS) method. Moreover, the strategy was used to detect the selected PFCs in water samples collected from Xiaoqinghe river and Gaobeidian wastewater. The achieved concentrations of PFCs were closed to those obtained by LC-MS/MS method. It is indicated that the proposed MALDI-TOF-MS method with TMGN as the matrix is much reliable and can be used as an alternative method to detect trace PFCs in environmental water samples.     

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.     

Development of extraction methods for the analysis of perfluorinated compounds in human hair and nail by high performance liquid chromatography tandem mass spectrometry

Perfluorinated compounds (PFCs) are ubiquitous in the environment and are becoming a public health concern. It is desirable to develop sensitive and accurate methods to measure PFCs in non-invasive matrices such as hair and nail for biomonitoring of body burden. Different extraction methods coupled with solid phase extraction were investigated for extraction efficiency. The extracts were separated, identified and quantified by liquid chromatography-tandem mass spectrometry. Extraction with acetonitrile proved to be the most efficient extraction method for human hair sample, while extraction by methanol with alkaline digestion performed best for human nail sample. The matrix recoveries of the optimized methods ranged from 78% to 116% for hair and from 87% to 126% for nail sample. The ranges of the limit of detection (LOD) were 0.026–0.069 ng/g and 0.023–0.094 ng/g for hair and nail, respectively. These methods were validated by evaluating LOD, accuracy and precision and were proven to be useful for measuring paired human hair and nail samples collected from the general population.