Health risks in infants associated with exposure to perfluorinated compounds in human breast milk from Zhoushan, China

Recent studies have reported the ubiquitous distribution of perfluorinated compounds (PFCs), especially perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), in wildlife and human whole blood or serum. In 2003 a solid phase extraction method was developed, which allowed the measurement of PFCs in human breast milk. In the present study, PFCs in samples of human breast milk from 19 individuals from Zhoushan, China, were analyzed by modifying a previously established method, based on weak-anion exchange extraction. PFOS and PFOA were the two dominant chemicals detected in all the milk samples. Concentrations of PFOS and PFOA ranged from 45 to 360 ng/L and 47 to 210 ng/L, respectively. The maximum concentrations of other PFCs were 100 ng/L for perfluorohexanesulfonate (PFHxS), 62 ng/L for perfluorononanoate (PFNA), 15 ng/L for perfluorodecanoate (PFDA) and 56 ng/L for perfluoroundecanoate (PFUnDA). Statistically significant correlations between various PFCs suggested a common exposure source to humans. No statistically significant correlation was found between concentrations of either PFOS or PFOA and maternal age, weight, or infant weight. Rate of consumption of fish was found to be positively correlated with PFNA, PFDA, and PFUnDA concentrations. Daily intake of PFOS for the child via breast milk with greater PFOS concentrations exceeded the predicted conservative reference dose in 1 of 19 samples, indicating that there may be a small potential risk of PFOS for the infants in Zhoushan via the consumption of breast milk.     

Perfluorooctanesulfonate and related fluorochemicals in human blood samples from China

Perfluorooctanesulfonylfluoride (POSF)-based compounds have been manufactured and used in a variety of industrial applications. These compounds degrade to perfluorooctanesulfonate (PFOS) which is regarded as a persistent end-stage metabolite and is found to accumulate in tissues of humans and wildlife. PFOS, perfluorohexanesulfonate (PFHxS), perfluorooctanoate (PFOA), and perfluorooctanesulfonamide (PFOSA) have been found in human sera from the United States. In this study, concentrations of PFHxS, perfluorobutanesulfonate (PFBS), PFOS, perfluorohexanoic acid (PFHxA), PFOA, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), and PFOSA were measured in 85 samples of whole human blood collected from nine cities (eight provinces) in China, including Shenyang (Liaoning), Beijing (Hebei), Zhengzhou (Henan), Jintan (Jiangsu), Wuhan (Hubei), Zhoushan (Zhejiang), Guiyang (Guizhou), Xiamen (Fujian), and Fuzhou (Fujian). Among the 10 perfluorinated compounds (PFCs) measured, PFOS was the predominant compound. The mean concentration of PFOS was greatest in samples collected from Shenyang (79.2 ng/mL) and least in samples from Jintan (3.72 ng/mL). PFHxS was the next most abundant perfluorochemical in the samples. No age-related differences in the concentrations of PFOA, PFOS, PFOSA, and PFHxS were observed. Gender-related differences were found,with males higher for PFOS and PFHxS, and females higher in PFUnDA. Concentrations of PFHxS were positively correlated with those of PFOS, while concentrations of PFNA, PFDA, and PFUnDA were positively correlated with those of PFOA. There were differences in the concentration profiles (percentage composition) of various PFCs in the samples among the nine cities.     

Association of Perfluorooctanoic Acid with HDL Cholesterol and Circulating miR-26b and miR-199-3p in Workers of a Fluorochemical Plant and Nearby Residents

Perfluoroalkyl chemicals (PFCs) are stable man-made compounds with many industrial and commercial uses. Concern has been raised that they may exert deleterious effects, especially on lipid regulation. We aimed to assess exposure to perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), and seven other PFCs in occupational workers from a fluorochemical plant and nearby community residents, and to investigate the association between PFOA and serum biomarkers. Serum biomarkers included not only biochemical parameters, such as lipids and enzymes, but also circulating microRNAs (miRNAs). Samples were analyzed by high-pressure liquid chromatography/tandem mass spectrometry (HPLC-MS/MS). Circulating miRNA levels were detected by quantitative polymerase chain reaction (PCR). Analyses were conducted by correlation and linear regression. We detected PFOS, PFOA, perfluorohexane sulfonate (PFHxS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) in all samples. The median levels of serum PFOA and PFOS were 284.34 ng/mL and 34.16 ng/mL in residents and 1635.96 ng/mL and 33.46 ng/mL in occupational participants, respectively. To our knowledge, we found for the first time that PFOA was negatively associated with high-density lipoprotein cholesterol (HDL-C) in workers using linear regression after adjusting for potential confounders. Circulating miR-26b and miR-199a-3p were elevated with serum concentration of PFOA. Although the limitations of small sample size and the cross-sectional nature of the current study constrained causal inferences, the observed associations between PFOA and these serum biomarkers warrant further study.     

Perfluorinated contaminants in sediments and aquatic organisms collected from shallow water and tidal flat areas of the Ariake Sea, Japan: environmental fate of perfluorooctane sulfonate in aquatic ecosystems

Perfluorinated compounds (PFCs), such as perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), perfluorohexane sulfonate (PFHS), and perfluorooctane sulfonamide (PFOSA) are widely distributed in aquatic ecosystems. Despite studies reporting the occurrence of PFCs in aquatic organisms, the fate of PFCs in tidal flat and marine coastal ecosystems is not known. In this study, we determined concentrations of PFOS, PFOA, PFNA, PFHS, and PFOSA in sediments; benthic organisms, including lugworm, mussel, crab, clam, oyster, and mudskipper fish from tidal flat; and shallow water species, such as filefish, bream, flounder, shark, finless porpoise, gull, and mallard collected from the Ariake Sea, Japan. PFOS and PFOA were detected in most of the samples analyzed, followed by PFNA, PFOSA, and PFHS. In shallow water species, PFOS was the dominant contaminant, and elevated concentrations were found in higher trophic level species, such as marine mammals and omnivorous birds. These results suggest biomagnification of PFOS through the coastal food chain. In contrast, PFOA was the most abundant compound in tidal flat organisms and sediments. PFOA concentrations in sediments, lugworms, and omnivorous mudskippers in tidal flat were approximately 1 order of magnitude greater than the levels of PFOS. This indicates differences in exposure pattern and bioavailability of PFOS and PFOA between shallow water and tidal flat organisms. The accumulation profiles of PFCs were compared with those of organochlorines (polychlorinated biphenyls, PCB), organotin (tributyltin,TBT), and polycyclic aromatic hydrocarbons (PAHs) in tidal flat and shallow water samples collected from the Ariake Sea. Concentrations of PFCs in sediments and in tidal flat organisms were significantly lower than that found for PCBs, TBT, and PAHs. Nevertheless, PFOS concentrations in shallow water species were comparable to and/or significantly greater than those of other classes of contaminants. This implies that the aqueous phase is a major sink for PFCs, which is different from what was observed for nonpolar organic pollutants.     

Temporal and spatial trends of perfluorinated compounds in ringed seal (Phoca hispida) from Greenland

Perfluorinated compounds (PFCs), such as perfluorooctane sulfonate (PFOS) and related compounds, have been identified as global pollutants and have shown their bioaccumulation into higher trophic levels in the food chain. PFCs have been found in remote areas far from sources, such as the Arctic. In this study spatial and temporal trends in the concentrations of selected PFCs were measured using archived liver samples of ringed seal (Phoca hispida) from East and West Greenland. The samples were collected in four different years at each location, between 1986 and 2003 in East Greenland and between 1982 and 2003 in West Greenland. PFOS was the major contributor to the burden of PFCs in samples, followed by perfluoroundecanoic acid (PFUnA). Perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) were also detected in most samples. Perfluorohexane sulfonate (PFHxS) and perfluorooctane sulfonamide (PFOSA) were only found sporadically. Perfluorooctanoic acid was not found in detectable concentrations in any sample. Regression analysis of logarithmic transformed PFOS, PFDA, and PFUnA median concentrations indicated a significant temporal trend with increasing concentrations at both locations. A spatial trend in PFOS concentrations (ANOVA, p < 0.0001) was observed between the two sampling locations, with significantly higher concentrations in seals from East Greenland.     

Perfluorinated compounds in coastal waters of Hong Kong, South China, and Korea

Perfluorinated compounds (PFCs), such as perfluorooctanesulfonate (PFOS) and related compounds, have recently been identified in the environment. PFOS, the terminal degradation product of many of the PFCs, has been found globally in many wildlife species, as well as open ocean waters, even in remote regions far from sources. In this study, a solid-phase extraction procedure coupled with high-performance liquid chromatography interfaced to high-resolution mass spectrometry was used to isolate, identify, and quantify small concentrations of PFCs in seawater. These techniques were applied to investigate the local sources of PFCs in several industrialized areas of Asia and provide information on how the PFCs are circulated by coastal currents. Ranges of concentrations of PFOS in coastal seawaters of Hong Kong, the Pearl River Delta, including the South China Sea, and Korea were 0.09-3.1, 0.02-12, and 0.04-730 pg/mL, respectively, while those of perfluorooctanoic acid (PFOA) were 0.73-5.5, 0.24-16, and 0.24-320 pg/mL, respectively. Potential sources of PFCs include major industrialized areas along the Pearl River Delta of southern China and major cities of Korea, which are several of the fastest growing industrial and economic regions in the world. Detectable concentrations of PFOS and PFOA in waters of southern China were similar to those in the coastal marine environment of Japan and certain regions in Korea. Concentrations of PFCs in several locations in Korean waters were 10-100-fold greater than those in the other locations on which we report here. The spatial and seasonal variations in PFC concentrations in surface seawaters in the Pearl River Delta and South China Sea indicate the strong influence of the Pearl River discharge on the magnitude and extent of PFC contamination in southern China. All of the concentrations of PFOS were less than those that would be expected to cause adverse effects to aquatic organisms or their predators except for one location in Korea adjacent to an industrialized area. Hazard quotients were from <0.001 to 0.002 for aquatic animals and ranged from <0.001 to 17 for predatory birds.     

水产品中全氟辛酸和全氟辛烷磺酸检测技术 及污染现状

全氟辛酸(PFOA)和全氟辛烷磺酸(PFOS)是环境中广泛存在、较为典型的两种全氟化合物。针对水产品中PFOA和PFOS的检测技术和污染现状进行研究,进而研究其暴露途径、生物富集规律等内容,并基于此预测污染物环境分布、环境行为,以及相应地制定环境水和水产品质量安全标准,对于确保消费者食用安全具有重要意义。本文总结、分析了水产品中PFOA和PFOS的检测技术研究进展,及水环境和水产品中污染情况,对目前存在的问题及今后的研究方向进行了讨论和展望,以期为中国水产品中全氟化合物的监控和质量安全风险评估提供参考。     

Automated solid-phase extraction and measurement of perfluorinated organic acids and amides in human serum and milk

Organic fluorochemicals are used in multiple commercial applications including surfactants, lubricants, paints, polishes, food packaging, and fire-retarding foams. Recent scientific findings suggest that several perfluorochemicals (PFCs), a group of organic fluorochemicals, are ubiquitous contaminants in humans and animals world wide. Furthermore, concern has increased about the toxicity of these compounds. Therefore, monitoring human exposure to PFCs is important. We have developed a high-throughput method for measuring trace levels of 13 PFCs (2 perfluorosulfonates, 8 perfluorocarboxylates, and 3 perfluorosulfonamides) in serum and milk using an automated solid-phase extraction (SPE) cleanup followed by high-performance liquid chromatography-tandem mass spectrometry. The method is sensitive, with limits of detection between 0.1 and 1 ng in 1 mL of serum or milk, is not labor intensive, involves minimal manual sample preparation, and uses a commercially available automated SPE system. Our method is suitable for large epidemiologic studies to assess exposure to PFCs. We measured the serum levels of these 13 PFCs in 20 adults nonoccupationally exposed to these compounds. Nine of the PFCs were detected in at least 75% of the subjects. Perfluorooctanesulfonate (PFOS), perfluorohexanesulfonate (PFHxS), 2-(N-methylperfluorooctane-sulfonamido)acetate (Me-PFOSA-AcOH), perfluorooctanoate (PFOA), and perfluorononanoate (PFNA) were found in all of the samples. The concentration order and measured levels of PFOS, PFOA, Me-PFOSA-AcOH, and PFHxS compared well with human serum levels previously reported. Although no human data are available for the perfluorocarboxylates (except PFOA), the high frequency of detection of PFNA and other carboxylates in our study suggests that human exposure to long-alkyl-chain perfluorocarboxylates may be widespread. We also found PFOS in the serum and milk of rats administered PFOS by gavage, but not in the milk of rats not dosed with PFOS. Furthermore, we did not detect most PFCs in two human milk samples. These findings suggest that PFCs may not be as prevalent in human milk as they are in serum. Additional studies are needed to determine whether environmental exposure to PFCs can result in PFCs partitioning into milk. Large epidemiological studies to determine the levels of PFCs among the U.S. general population are warranted.     

Determinants of fetal exposure to polyfluoroalkyl compounds in Baltimore, Maryland

Polyfluoroalkyl compounds (PFCs), such as perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), are ubiquitous, man-made chemicals. Human data suggest that in utero exposures to these chemicals occur and some evidence of developmental toxicity in animals exists. To assess the distribution and determinants of fetal exposure to PFCs, we analyzed cord serum samples from 299 singleton newborns delivered between 2004 and 2005 in Baltimore, MD for 10 PFCs by employing on-line solid-phase extraction coupled with reversed-phase high-performance liquid chromatography-tandem mass spectrometry. PFOS and PFOA were detected in 99 and 100% of umbilical cord sera, with geometric mean concentrations of 4.9 and 1.6 ng/mL, respectively. PFOS and PFOA concentrations were highly correlated (Pearson's r = 0.64 after natural log transformation, p < 0.01). Eight other PFCs were detected less frequently and at lower concentrations than PFOS and PFOA. Geometric mean concentrations of PFOS for Asians (6.0 ng/mL) and Blacks (5.1 ng/mL) were higher than those for Whites (4.2 ng/mL), while PFOA levels were more evenly distributed by race. Other maternal demographic and socioeconomic characteristics, including age, education, marital status, and living in the city limits were not significantly associated with cord concentrations. Our findings suggest that in utero exposure to PFOS and PFOA is ubiquitous in a population of babies born in Baltimore, MD.     

Monitoring of perfluorinated compounds in edible fish from the Mediterranean Sea

Perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS) are environmental contaminants belonging to a chemical group known as perfluorinated compounds (PCFs). The United States Environmental Protection Agency (US EPA) considers both compounds to be carcinogenic. The goal of the present study was to evaluate the contamination levels of PFOS and PFOA in edible fish of the Mediterranean Sea. Twenty six fish muscles, 17 fish livers, five series of cephalopods (each composed of ten specimens) and thirteen series of bivalves (each composed of about 50 specimens) were used for the investigation. A fast sample treatment, followed by an LC–ESI–MS/MS method is described for the identification, and quantification of PFOA and PFOS in fish. The method was in-house-validated through the determination of precision, accuracy, specificity, calibration curve, decision limit (CCα), and detection capability (CCβ). The results showed PFOA and PFOS levels in fishes and molluscs lower than those reported for analogue matrices in different geographic areas. Therefore, our biomonitoring results did not show that the Mediterranean Sea had any particularly alarming pollution by PFCs, although it is located in a semi-closed basin with scarce water change. Nonetheless, a worrying element is that a few fish showed extremely high contamination by PFOA and PFOS. This finding needs further clarification in order to assess whether such unusual contamination is linked to “dot-like” pollutant release, which could explain the anomaly.     

Contamination and effects of perfluorochemicals in Baikal seal (Pusa sibirica). 1. Residue level, tissue distribution, and temporal trend

Concentrations of perfluorochemicals (PFCs) including perfluoroalkylsulfonates (PFSAs) and perfluoroalkylcarboxylates (PFCAs) were determined in liver and serum of Baikal seals (Pusa sibirica) collected from Lake Baikal, Russia in 2005. Among the 10 PFC compounds measured, perfluorononanoic acid (PFNA, 3.3-72 ng/g wet wt) concentrations were the highest in liver, followed by perfluorooctanesulfonate (PFOS, 2.6-38 ng/g). The accumulation profile of long-chain (C7-C12) PFCAs in particular, the predominance of PFNA, indicated that 8:2 fluorotelomer alcohol or commercially manufactured PFNA is a major local source of PFCs in Lake Baikal. No gender-related differences in the concentrations of individual PFCs or total PFCs were found. Tissues from pups and juveniles contained relatively higher concentrations of PFCs than tissues from subadults and adults, suggesting that maternal transfer of PFCs is of critical importance. Comparison of concentrations of PFCs in livers and sera collected from the same individuals of Baikal seals revealed that residue levels of PFOS, PFNA, perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA) were significantly higher in liver than in serum. The concentration ratios of PFNA and PFDA between liver and serum were calculated to be 14 and 15, respectively, whereas the ratio of PFOS was 2.4. This suggests preferential retention of both PFNA and PFDA in liver. Concentrations of PFOS, PFNA, and PFDA in liver were significantly correlated with those in serum, whereas concentrations of PFUnDA were not correlated in between the two tissues, suggesting differences in pharmacokinetics among these PFCs. Temporal comparisons of hepatic PFC concentrations in seals collected between 1992 and 2005 showed that the concentrations of PFOS (p = 0.0006), PFNA (p = 0.061) and PFDA (p = 0.017) were higher in animals collected in recentyears, indicating ongoing sources of PFC contamination in Lake Baikal.     

Perfluorinated compounds in human milk from Massachusetts, U.S.A

Perfluorinated compounds (PFCs), notably perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), have been reported in human blood. Furthermore, the occurrence of PFCs in the blood of newborn babies, coupled with the need to study the potential association of PFC exposure with birth outcomes in neonates, suggests the need for determining the sources and magnitude of exposure in infants. In this study, nine PFCs were measured in 45 human breast milk samples collected in 2004 from Massachusetts, U.S.A. PFOS and PFOA were the predominant PFCs found at mean concentrations of 131 and 43.8 pg/mL, respectively. Comparison of the ratio of PFOS to PFOA in human milk with the ratios published for human serum from the U.S. female population suggested preferential partitioning of PFOA to milk. Concentrations of PFOA were significantly higher in the milk of mothers nursing for the first time (n = 34) than in the milk of mothers who have previously nursed (n = 8). Based on the estimated body weight and milk intake, the average and highest daily intakes of total PFCs by infants were 23.5 and 87.1 ng/kg bw, respectively. We found that the daily ingestion rates of PFOS and PFOA did not exceed the tolerable daily intake recommended by the U.K. Food Standards Agency. This is the first study to measure the occurrence of PFCs in human milk from the U.S.A.     

Distribution of perfluorooctane sulfonate and other perfluorochemicals in the ambient environment around a manufacturing facility in China

Perfluorinated compounds (PFCs) can be released to the surrounding environment during manufacturing and usage of PFC containing products, which are considered as main direct sources of PFCs in the environment. This study evaluates the release of perfluorooctane sulfonate (PFOS) and other PFCs to the ambient environment around a manufacturing plant. Among the nine PFCs analyzed, only PFOS, perfluorooctanoic acid (PFOA), and perfluorohexane sulfonate (PFHxS) were found in dust, water, soil, and chicken eggs. Very high concentrations of PFOS and PFOA were found in dust from the production storage, raw material stock room, and sulfonation workshop in the manufacturing facility, with the highest value at 4962 μg/g (dry weight) for PFOS and 160 μg/g for PFOA. A decreasing trend of the three PFCs concentrations in soils, water, and chicken eggs with increasing distance from the plant was found, indicating the production site to be the primary source of PFCs in this region. Risk quotients (RQs) assessment for surface water >500 m away from the plant were less than unity. Risk assessment of PFOS using predicted no-effect concentration (PNEC, 3.23 ng/g on a logarithmic scale) indicated no immediate ecological risk of a reduction in offspring survival. PFOS concentrations in most egg samples did not exceed the benchmark concentration derived in setting a reference dose for noncancer health effects (0.025 μg/(kgxd)).     

Perfluorinated compounds in fish and blood of anglers at Lake Möhne, Sauerland area, Germany

Perfluorinated compounds (PFCs) were measured in fish samples and blood plasma of anglers in a cross-sectional study at Lake Mo?hne, Sauerland area, Germany. Human plasma and drinking water samples were analyzed by solid phase extraction, high-performance liquid chromatography (HPLC), and tandem mass spectrometry (MS/MS). PFCs in fish fillet were measured by ion pair extraction followed by HPLC and MS/MS. PFOS concentrations in 44 fish samples of Lake Mo?hne ranged between 4.5 and 150 ng/g. The highest median PFOS concentrations have been observed in perches (median: 96 ng/g) and eels (77 ng/g), followed by pikes (37 ng/g), whitefish (34 ng/g), and roaches (6.1 ng/g). In contrast, in a food surveillance program only 11% of fishes at retail sale contained PFOS at detectable concentrations. One hundred five anglers (99 men, 6 women; 14-88 years old; median 50.6 years) participated in the human biomonitoring study. PFOS concentrations in blood plasma ranged from 1.1 to 650 μg/L (PFOA: 2.1-170 μg/L; PFHxS: 0.4-17 μg/L; LOD: 0.1 μg/L). A distinct dose-dependent relationship between fish consumption and internal exposure to PFOS was observed. PFOS concentrations in blood plasma of anglers consuming fish 2-3 times per month were 7 times higher compared to those without any fish consumption from Lake Mo?hne. The study results strongly suggest that human internal exposure to PFC is distinctly increased by consumption of fish from PFC-contaminated sites.     

基于液相色谱-串联质谱法的纺织品中痕量全氟化合物的测定

采用超声法提取纺织品中的全氟化合物。以C18为分析柱,甲醇-5 mmol/L乙酸铵为梯度洗脱淋洗液, 13 min内即可分离全氟己酸(PFHxA),全氟辛酸(PFOA),全氟壬酸(PFNA),全氟癸酸(PFDA),全氟十一酸(PFuDA),全氟十二酸(PFDoA), 全氟丁烷磺酸(PFBS),全氟己烷磺酸(PFHxS),全氟辛烷磺酸(PFOS),全氟癸烷磺酸(PFDS) 10种分析物。以313.1/268.9,412.9/368.9,462.9/418.9,512.7/468.9,562.7/518.9,612.8/568.9,298.8/99,399.2/99,498.8/99,599/99分别对PFHxA,PFOA,PFNA,PFDA,PFuDA,PFDoA,PFBS,PFHxS,PFOS,PFDS进行监控和定量分析。利用同位素内标法进行定量,线性范围和添加回收率分别为0.5～10 µg/m2、84.6%～111.8%,检出限为0.5 µg/m2,低于欧盟指定针对纺织品1 µg/m2 的限定。结果表明,本方法准确、快速,并成功用于20种纺织品实样的检测。     

Analysis of Trace Metals and Perfluorinated Compounds in 43 Representative Tea Products from South China

Six trace metals (Cd, Pb, Cr, Cu, Zn, and Mn) and 2 perfluorinated compounds (PFCs), perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), were analyzed in 43 representative tea products (including 18 green, 12 Oolong, and 13 black teas) from 7 main tea production provinces in China, using the atomic absorption spectrophotometer for trace metals analysis and HPLC‐MS/MS for PFOS and PFOA analysis. The average contents of the 3 essential metals Mn, Cu, and Zn ions in the tea samples were 629.74, 17.75, and 37.38 mg/kg, whereas 3 toxic metals Cd, Cr, and Pb were 0.65, 1.02, and 1.92 mg/kg, respectively. The contents of heavy metals in the 3 types of tea were in the order of black tea > Oolong tea > green tea. Both PFOS and PFOA contents were low and PFOA content was higher than PFOS in the tea samples. The highest concentration of PFOA was 0.25 ng/g dry weight found in a Hunan green tea. The Principal component analysis was performed with the trace metals and PFCs to analyze the relationships of these indices. The results showed that black teas had higher trace metals and PFCs than green and Oolong teas, and the teas from Hunan and Zhejiang provinces had higher Pb and Cr than others.     

Perfluorinated compounds in the Cape Fear Drainage Basin in North Carolina

Concern over perfluorinated organic compounds (PFCs), e.g., perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), is due to a number of recent studies which show that the PFCs are persistent, bioaccumulative, and toxic in animals. Despite sustained interest in this topic, little information is available concerning the environmental distributions of the compounds. In this study, a new method was developed for the analysis of 10 target PFCs and its performance was examined in a systematic evaluation of surface water in the Cape Fear River Basin in North Carolina. One hundred samples from 80 different locations were collected during the spring of 2006. Detectable levels of the target PFCs were found in all samples, and were comparable to values reported previously, with maximum PFOS at 132 ng/L, PFOA at 287 ng/L, perfluorononanoic acid (C9) at 194 ng/L, and perfluoroheptanoic acid (C7) at 329 ng/L. In general, the lowest concentrations of the PFCs were found in the smallest tributaries while the highest levels were found in middle reaches of the Drainage Basin. Variability of PFC concentrations suggests a series of source inputs throughout the Basin. Seventeen sample sites (22%) had PFOS concentrations greater than 43 ng/L, a conservative safe water concentration estimated to be protective of avian life. In addition, a total of 26 sites (32%) had PFOA concentrations above 40 ng/L.     

食品中全氟辛酸、全氟辛基磺酸的检测技术研究进展

全氟化合物(Perfluorinated compounds,PFCs)是一类含碳-氟键的高度稳定的极性有机化合物,全氟辛酸(Pentadecafluorooctanoic acid,PFOA)和全氟辛烷磺酸(Sperfluorooctanesulphonate,PFOS)是环境中广泛存在得两种典型全氟化合污染物,这两种典型的全氟化合物广泛应用于化工领域。此类全氟化合物因为具有持久的稳定性、生物积累性和多种毒性等,严重危害到了人类健康和其生存环境,多国政府纷纷颁布法令法规限制PFOA、PFOS的使用。因此食品基体中PFOA、PFOS的检测分析成为了当下分析科学研究的热点。本文首先对全氟化合物的结构、类型、极性等理化性质和全氟污染物的危害毒性进行概述,其次根据其化学性质以及参考国标等方法,梳理了国内外各种前处理方法,如：液液萃取、液固萃取、固相萃取、超声辅助萃取、QuEChERs等。其中QuEChERs方法结合多步净化方法能够最大程度降低食品中的基质效应。此外比较了气相色谱、液相色谱等方法在分离检测方面的优缺点,比较了已有文献中不同前处理方法和检测方法下的检出限、回收率、RSD等数据,结果发现UPLC-MS/MS法由于低检出限,方法稳定,检测快速,结果准确确等优点,仍为当下主流的检测手段。本文对于制定相应食品中全氟化合物质量安全标准,确保消费者食用安全具有重要意义,并总结了当下全氟化合物所遇检测的瓶颈,期望能为当下国内外全氟化合物污染防治和制定标准提供参考依据。     

Perfluorinated surfactants in surface, subsurface water and microlayer from Dalian Coastal waters in China

Two predominant perfluorinated compounds (PFCs), Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), in surface water (SW, 0-20 cm), subsurface water (SSW, > 30 cm depth), and sea surface microlayer (SML, 50 microm thickness) were measured from Dalian Coastal waters in China. The SML samples were collected using glass-plate dipping method. Analysis of the PFCs was conducted through solid-phase extraction, followed by LC/MS-SIM. The PFC's concentrations in SW samples were consistent with previously reported data in this region. Significantly higher concentrations of PFCs were found in SML samples than corresponding SSW samples. The enrichment factors (EF = C(SML)/C(SSW)) for PFOS were as high as 24-109 atthree near-shore sites. The concentration in SW was also generally higher than corresponding SSW samples, giving C(SW)/C(SSW) mean ratios of 1.5 and 1.4 for PFOS and PFOA, respectively. This apparent enrichment of PFCs in surface water, especially in the microlayer, has implications for designing measurement techniques, understanding their distributions, and sea spray-mediated transport in the environment.