加速溶剂萃取-气相色谱-质谱法同时测定土壤中7种Aroclor系列多氯联苯

采用加速溶剂萃取,Florisil固相萃取小柱净化,GC-MS法同时测定土壤中7种多氯联苯(Aroclor 1016、1221、1232、1242、1248、1254、1260)的含量。建立了一种全新的Aroclor系列多氯联苯的定量测定方法,根据氯代联苯峰在单种Aroclor和7种Aroclor混合物中峰高比值(K)固定不变的原理,通过7种Aroclor混合物的标准曲线,计算得出各种Aroclor的标准曲线,测定样品中Aroclor的含量;采用建立多元一次方程组的方法,测定样品中多种不同浓度Aroclor的含量,大大提高了分析效率。7种Aroclor混合物和Aroclor1242、Aroclor1260的土壤加标样品回收率为90.5%~109%,RSD为0.96%~9.38%(n=5),均能满足分析准确度和精密度的要求。     

土壤中多氯联苯简化计算定量方法研究

针对含有两种或两种以上Aroclor多氯联苯混合物的样品,研究其简便易行的定性、定量方法。将复杂样品中的多氯联苯分别折算成Aroclor 1016、1242、1260含量,在定性的同时予以定量。3种不同组分混合样品的加标回收率分别为68.2%～80.6%、67.9%～74.2%、67.1%～76.8%,实际土壤样品的测定结果与已有研究结果相吻合。方法缺点为无法识别和计算各Aroclor之间的准确比例,可用于应急监测复杂组分样品中多氯联苯的测定。     

空气中多氯联苯的定量研究

使用大流量采样器,分别以石英纤维滤膜(QFF)和聚氨基甲酸乙酯泡沫(PUF)对空气中颗粒相和气相PCBs进行采集。以GC/MS为检测手段,采用选择性离子检测技术(SIM)对PCBs进行定性,内标法结合响应因子法进行PCBs的定量。PCBs的仪器检测限为4.40~93.60pg,回收率为68.57%~121.28%。气相和颗粒相PCBs的方法检测限分别为2.36~381.75fg/m3和2.78~348.81fg/m3。吸附和穿透试验结果表明,在采样流速为0.23m3/min、采样时间为24h的条件下,吸附和穿透情况对空气中PCBs的定量不会产生显著影响。     

环境样品中 PCBs 的测定

通过碱解、酸洗、萃取、净化、浓缩、脱硫等步骤处理实际样品,利用毛细管柱GC/ECD进行PCBs的定性和定量.方法定性准确,定量良好,具有较高的回收率.各同系物的方法检出限,水样为0.01～0.08ng/L;土壤样为0.003～0.03μg/kg,可以应用于土壤、沉积物、水样、油样等环境样品中PCBs的测定     

SUMMA罐采样-GC×GC-TOFMS同时测定空气中有机硫化物

研究了SUMMA罐采样-全二维气相色谱-飞行时间质谱法测定环境空气中有机硫化物。采用SUMMA罐采集样品,自动进样器进样,三级冷阱预浓缩样品,全二维气相色谱-飞行时间质谱法(GC×GC-TOFMS)测试分析,以较长的非极性柱Rxi-5MS(30 m×320μm×1.0μm)作为第一维柱,较短的中等极性柱DB-17MS(2.0 m×0.1 mm×0.1μm)作为第二维柱,对环境空气中的有机硫化物进行了定性定量分析。结果表明,该方法特性不仅满足方法学要求,而且比《空气和废气监测分析方法》(第4版)推荐的方法更加优异,能够准确、快速地检测环境空气中有机硫化物。     

基于主成分分析的上海市大气降水中DL-PCBs来源初判

运用主成分分析法(PCA)初步判断2010年11月—2011年10月覆盖上海市18个行政区20个采样点大气降水中类二噁英多氯联苯(DL-PCBs)的来源。结果表明,研究期间上海市大气降水中DL-PCBs成分以五氯代PCBs为主。PC1判断可能为含DL-PCBs成分的日本PCBs产品KC500,PC2判断可能为含DL-PCBs成分的日本KC600及美国Aroclor1260产品,PC3可能为国产PCBs产品。由此判断,上海市大气降水中DL-PCBs受多种来源共同影响。前两大主要来源可能为来自环境中美国Aroclor1260和日本KC500、KC600产品的历史使用残留,第三大来源才可能是我国国产PCBs产品在大气环境中的残留。     

7种指示性多氯联苯混合标准样品量值不确定度研究

分析并评估了异辛烷中7种指示性多氯联苯(PCBs)混合标准样品的量值不确定度。通过分析PCBs纯品中结构相似物、水分、无机物等杂质的含量,采用质量平衡法对PCBs纯品的纯度进行了定值。结果显示,7种指示性PCBs纯品的纯度为98.24%~99.92%,纯度不确定度为0.08%~1.28%。采用称量-容量法制备了各组分浓度均为50.0 μg/mL的异辛烷中7种指示性PCBs混合标准样品,全面分析了各组分的量值不确定度来源,主要包括样品配制、均匀性和长期稳定性等引入的不确定度。结果表明,该标准样品中,7种指示性PCBs组分的合成扩展不确定度为0.7~1.7 μg/mL。该标准样品量值准确且具有计量溯源性,可为我国PCBs相关国际履约监测和新污染物监测提供有效支撑。     

气相色谱法测定水体中多氯联苯Aroclor系列

采用液液萃取—气相色谱法(GC-ECD)测定水体中多氯联苯Aroclor系列Aroclor1016、Aroclor1221、Aroclor1232、Aroclor1242、Aroclor1248、Aroclor1254、Aroclor1260。样品经正己烷溶剂萃取,再经全自动样品浓缩仪(EVA)浓缩萃取液至1 mL,供气相色谱仪测定,外标法定量,加标回收率在75%~110%之间,检出限为0.1μg/L。该方法采用双塔双柱双检测器,排除了误检和其他物质的干扰,保证了分析结果的可靠性,方法简单、灵敏、准确。     

气相色谱／傅立叶变换红外光谱（GC／FT—IR）系统分析有机污染物

1 概述气相色谱(GC)可卓有成效地分离测定环境样品中复杂、痕量、多组分的有机污染物,而傅立时变换红外光谱能提供完整的分子结构信息,因而GC/FTIR系统兼两者之长,适于分离、鉴定多组分的混合物,GC/FTIR系统具有如下几个特点:     

硅胶分离-气相色谱法测定海水样品中的有机氯农药及多氯联苯

建立了硅胶净化-具电子捕获检测器气相色谱(GC-ECD)测定海水样品中有机氯农药(OCPs)、多氯联苯(PCBs)的方法。海水样品经正己烷萃取,浓缩萃取液后过硅胶层析柱,通过梯度淋洗进行样品的净化和分离,采用GC-ECD进行分析测试。OCPs回收率达70.7%~109.2%,PCBs回收率达92.6%~119.2%。采用GC-MS进行辅助确证,结果表明,方法可行。     

Source and risk assessment of PCBs in sediments of Fenhe reservoir and watershed, China

The concentrations of polychlorinated biphenyls (PCBs) in sediments from the Fenhe reservoir and watershed were detected at 28 sites in wet and dry seasons. The ∑(123)PCBs ranged from n.d. to 126.49 ng g(-1) dw. The dominated congeners were tri-PCBs (34.29%) and tetra-PCBs (24.05%). In the Fenhe reservoir, ∑(123)PCBs presented a decreasing trend, while percentages of low chlorinated congeners showed an increasing trend. For the temporal variations, PCBs homologues profiles of sediment samples and spatial distribution of ∑(123)PCBs for the two periods were similar (with CD = 0.021 and r(2) = 0.999 respectively), although PCBs concentrations in the wet season were significantly higher than in the dry season. PCA was applied to analyze the possible sources for PCBs, suggesting that PCBs might be mainly influenced by Aroclor 1016 and 1242. Compared with 3 established sediment quality guidelines, levels of PCBs in sediments of the investigated watershed might have a potential biological impact, especially in the wet season.     

Remobilization of polychlorinated biphenyls from sediment and its consequences for their transport in river waters

A laboratory experiment was performed to examine the remobilization of indicator polychlorinated biphenyls (iPCBs) from sediments and its results were applied to the real-world data for explaining the transport of PCBs in river. Seven PCB concentrations were determined in three series of model water–sediment systems (3 g of river sediment, three different volumes of distilled water (0.5, 0.25, and 0.15 ml), and 5 mg of biocide) after 11 days of incubation. Solid-phase extraction was used for separation of analytes from the aqueous phase and solvent extraction for isolation of analytes from the sediments, respectively. The extracts were analyzed for individual iPCB congeners using gas chromatography–mass spectrometry method. For each series of the experiment, the concentrations of PCBs in aqueous phase were similar. The average sediment/water partition coefficient value was 10⁴?l/kg. The solubility of individual PCB congeners in water did not influence the desorption of PCBs from the sediment. Although the dominant form of PCBs in a water–sediment system occurs as suspended and colloidal fractions, these compounds are transported mostly in a dissolved form. Suspended and colloidal matter is a major sink for PCBs in low-energy aquatic environments. In contrast, the dissolved PCBs are readily transported in running waters. The mobilization of PCBs from sediments to aqueous phase, with respect to their solubility in water, seems to be limited, thus reducing the risk of secondary pollution.     

PCB congener distribution in estuarine water,sediment and fish samples: implications for monitoring programs

Traditional analyses for PCBs in environmental matrices havefocused on commercial Aroclor mixtures with detection limits inthe 100 to 1000 part per trillion range. This approach hasrecently been supplanted by analyses for specific PCB compoundscalled congeners with detection limits less than 0.5 ppt. At thenational level, total PCB determinations based upon selected PCBcongeners typically characterize analyses of surface water,sediment and tissue. These federal efforts rely on a suite of 18to 20 congeners out of a total of 209 congeners to characterizetotal PCB. The present study compares total PCB estimates basedupon this subset of congeners with estimates based upon anexpanded list of 81 congeners from water, sediment and fishtissue collected from the Delaware Estuary.Analytical data from monitoring programs conducted in theDelaware Estuary by the Delaware River Basin Commission, NOAANational Ocean Service, U.S. Army Corps of Engineers and the U.S.Environmental Protection Agency from 1996 to 1998 were evaluated. Total PCB estimates derived from the different sets of congeners,including the adjustment factor of 2.0 used by NOAA, werecompared. This evaluation indicated that differences existbetween total PCB determinations based upon these approaches, andthat these differences vary depending on the matrix analyzed. The bias associated with using a smaller set of PCB congeners,and the implications for risk assessment are discussed.     

Distribution of polychlorinated biphenyls and organochlorine pesticides in wild mussels from two different sites in central Croatian Adriatic coast

Levels of 24 organochlorine compounds were investigated in wild mussels collected at two locations (Krka estuary and Ka?tela Bay) on the Croatian Adriatic coast in 2003, 2005, 2006, 2007, and 2008. PCB and OCP ranges found at the two locations overlapped and followed similar profiles despite the differences between the two locations indicating that they share a common pollutants source. Among organochlorine pesticides, the dominant compound was DDT. Among indicator PCBs, the dominant compound was PCB-153, while PCB-118 was dominant among the remaining 11 congeners. Generally, the sum of six indicator PCBs was constantly greater than the sum of 11 congeners at both locations. α-HCH/γ-HCH and DDE/DDT ratios were below 1, indicating recent input of γ-HCH and DDT into the marine environment. In the investigated period, almost all organochlorine compounds reached the highest values in 2006. The levels of PCBs and OCPs in this study were considerably below the Croatian maximum permissible levels, confirming that they do not pose any threat for human health.     

Wild boar (Sus scrofa) as a bioindicator of organochlorine compound contamination in terrestrial ecosystems of West Pomerania Province, NW Poland

The aim of this study was to detect the presence and determine the residue levels of DDT, lindane, endrin and polychlorinated biphenyls (PCBs) in the liver of wild boars from the area of West Pomerania, NW Poland; to determine the activity of glutathione S-transferase (GST) as a biomarker of biological response and to assess the toxicological risk for consumers of the wild boar offal. The presence of pesticide residues and PCBs was found in all examined liver samples. The highest concentration was observed for endrin, and then, the descending order was PCBs >DDTs >lindane >dl-PCBs. The mean hepatic concentrations of endrin, PCBs, DDTs and lindane were 117.28, 78.59, 67.95 and 7.24 ng/g lipid weight, respectively. Among the dioxin-like PCB congeners, 118 and 156 were dominant in liver samples. The mean toxic equivalent (TEQ) level calculated for dl-PCBs was 2.10?±?1.11 pg WHO-PCB-TEQ/g. There was a statistically significant (p?<?0.05) negative correlation between the concentration of lindane, DDTs and PCBs (as a sum of indicator congeners) in the liver and in the activity of GST. However, GST activities showed no significant correlation with any of the dl-PCBs. In five boar liver samples, the levels of certain organochlorine compounds exceeded the maximum residue levels (MRLs). In one sample, the MRLs were exceeded simultaneously for PCBs, endrin and DDTs and in another one—for endrin and DDTs. In the remaining three samples, only PCB levels were exceeded.     

Polychlorinated biphenyls and selected organochlorine pesticides in serum of Slovak population from industrial and non-industrial areas

The concentrations of indicator polychlorinated biphenyls (PCBs No. 28, 52, 101, 138, 153 and 180) and organochlorine pesticides (HCB, p,p′-DDE and p,p′-DDT) in 121 blood serum specimens collected from non-occupationally exposed adults living in contaminated and comparison areas were determined using high-resolution gas chromatography/electron capture detection (HRGC/ECD). The sum of the serum concentrations of the three most abundant PCB congeners (No. 138, 153 and 180) found in participants (N?=?81) living in industrial areas near incinerators, metallurgical and chemical plants (Krompachy, Kosice, Nemecka and Sala) was significantly higher (p?N?=?40). Similarly, significant differences were observed for p,p′-DDE (p?p?U test between groups showed that the difference for HCB was not statistically significant (p?=?0.089). Age was positively correlated with the sum of PCBs (No. 138, 153 and 180), HCB and the sum of p,p′-DDE and p,p′-DDT (p?相似文献   

Organochlorine pesticides and polychlorinated biphenyl residues in reared and wild Dicentrarchus labrax from the Mediterranean Sea (Sicily, Italy)

The aim of this research was to compare the levels of organochlorine pesticides and PCBs in samples of Dicentrarchus labrax living in the Straits of Messina with samples cultivated in cages in the Mediterranean Sea. Muscles and liver tissues sampled over the months, within the same year, were analyzed. The quantitative determination of the organochlorine compounds was performed by GC-ECD and confirmed with GC–MS. The results showed that the concentrations of DDTs in muscles and livers as such of reared sea bass were in the range 0.2–1.3 μg/kg and 9.6 –48.4 μg/kg, respectively. In wild fish the concentrations of DDTs were very much lower: 0.1 μg/kg in muscles, 5.1–9.0 μg/kg in livers. Total PCBs levels were higher in cultivated sea bass than in wild fish; the concentration ranges were 5.3–59.7 μg/kg and 74.4–267.4 μg/kg in muscle and liver of reared samples, respectively, and 1.1–1.5 μg/kg and 63.2–109.4 μg/kg in muscle and liver of wild samples, respectively.