气相色谱法同时测定水中28种多氯联苯单体

采用液液萃取-浓硫酸磺化净化-气相色谱电子捕获检测器同时测定水中28种多氯联苯单体,必要时利用质谱选择离子监测模式定性,考察了萃取溶剂种类和体积及盐析效应对测定的影响,比较了硫酸磺化和弗罗里硅土柱对萃取液的净化效果。方法在1.00μg/L~47.6μg/L范围内线性良好,当取样体积为200 mL时,方法检出限为0.001μg/L~0.002μg/L,基体加标回收率为95.8%~103%,相对标准偏差≤18.7%。     

Accumulation of hydroxylated polychlorinated biphenyls (OH-PCBs) and implications for PCBs metabolic capacities in three porpoise species

The present study investigated polychlorinated biphenyls (PCBs) and hydroxylated metabolites of PCBs (OH-PCBs) in blood from three porpoise species: finless porpoises (Neophocaena phocaenoides), harbor porpoises (Phocoena phocoena), and Dall’s porpoises (Phocoenoides dalli). The porpoises were found stranded or were bycaught along the Japanese coast. Concentrations of OH-PCB were the highest in Dall’s porpoises (58 pg g⁻¹ wet wt), second highest in finless porpoises (20 pg g⁻¹ wet wt), and lowest in harbor porpoises (8.3 pg g⁻¹ wet wt). The concentrations in Dall’s porpoises were significantly higher than the concentrations in finless porpoises and harbor porpoises (p < 0.05 and p < 0.01, respectively). There was a positive correlation between PCB and OH-PCB concentrations (r = 0.67, p < 0.001), suggesting the possible concentration-dependent induction of CYP enzymes. The three porpoise species may have exceptionally low metabolic capacities compared with other marine and terrestrial mammals, because low OH-PCB/PCB concentration ratios were found, which were 0.0016 for Dall’s porpoises, 0.0013 for harbor porpoises, and 0.00058 for finless porpoises. Distinct differences in the OH-PCB congener patterns were observed for the three species, even though they are taxonomically closely related.     

西葫芦对土壤持久性有机氯化物污染的指示性研究

西葫芦(Cucurbita pepo L.)对土壤中持久性有机氯化物的超强吸收能力已被证实,意味其具有指示区域土壤持久性有机氯化物污染状况的潜能。本研究采用农田小区试验,考察了西葫芦不同组织器官(根、过渡茎、茎、叶和果实)在6个生长期对有机氯化物的累积吸收行为;采用同位素稀释高分辨气相色谱-高分辨质谱法,分析了种植土壤及西葫芦各组织器官中的21种有机氯农药(OCPs)和18种多氯联苯(PCBs)。结果表明,西葫芦可将根吸收的OCPs和PCBs传递到过渡茎和茎。不同生长期采集的西葫芦根、过渡茎和茎中的OCPs和PCBs浓度基本稳定,无明显生物稀释效应,且此3个组织器官中OCPs和PCBs的分布模式与土壤中的分布模式基本一致。因此,可以用西葫芦根和茎中持久性有机氯化物的浓度指示土壤中持久性有机氯化物的污染水平,根和茎的采样时间可以不受西葫芦生长期的限制。     

多氯联苯(PCBs)胁迫下鲫鱼肝脏EROD酶活性与血清性激素含量的相关性研究

以鲫鱼(Carassius auratus)为试验鱼类,研究其暴露于不同浓度的PCBs(多氯联苯)后鱼肝组织中EROD酶活性和血清性激素含量的动态变化,探讨了2者间的相关性。结果表明,鲫鱼在PCBs中暴露后,其肝脏组织中EROD酶被诱导,酶活性随PCBs浓度增大而增强,呈明显的剂量-效应关系;EROD酶活性随暴露时间延长而上升,10 d后达平衡;鲫鱼血清中睾酮含量随PCBs浓度增大和暴露时间延长呈下降趋势,但雌二醇含量则显著上升,表明PCBs对鱼类具有环境雌激素效应;在一定浓度范围内,EROD酶活性与血清睾酮含量呈负相关,与血清雌二醇含量呈正相关。因此可用鱼肝EROD酶和血清性激素含量的协同变化作为污染生物标志物来评价PCBs的早期污染生态效应。     

变压器油中多氯联苯的测定

着重研究变压器油中多氯联苯(PCBs)测定的样品前处理技术,确定了变压器油中PCBs分离的最佳条件,并应用GC/ECD测定PCBs总量.回收率在86％-110％之间,变异系数1％-3％.此外,采用GC/MS联用方法对变压器油中PCBs进行了定性分析.     

渤海湾脉红螺中多氯联苯和多溴联苯醚的测定分析

应用GC/HRMS对渤海湾脉红螺中的PCBs(多氯联苯)和PBDEs(多溴联苯醚)2类持久性有机污染物进行了测定分析.结果表明:雄性脉红螺中PCB(3～10氯代)的质量分数(10.1 ng/g,以干质量计)和PBDEs(BDE28、BDE47、BDE99、BDE100、BDE153、BDE154、BDE209)的质量分数(1.74 ng//g)均高于雌性脉红螺(分别为8.09和1.38 ng/g);雄性脉红螺中PCBs的WHO-TEQ(毒性当量,8.41 pg/g,以脂肪质量计)高于雌性脉红螺(4.34 pg/g),其中PCB118和PCB126的贡献率分别为13%和77%.脉红螺的不同组织中,性腺和消化腺中w(PCBs)和w(PBDEs)最高,肌肉组织中最低;主要同类物为PCB118、PCB101、PCB28、PCB138、PCB180、PCB52、PCB153和5-PCB以及BDE209.渤海湾脉红螺的消化腺可以作为PCBs和PBDEs的生物指示物.     

加速溶剂萃取-气相色谱质谱法测定海洋沉积物中多氯联苯残留

样品采用加速溶剂萃取,萃取液依次经复合硅胶和石墨化炭黑柱净化后,采用GC-MS法测定样品中的多氯联苯残留。结果表明,方法检出限为(0.005～0.038)×10-9(湿重),样品加标回收率为68.5%～108.4%,RSD为2.1%～11.8%。本方法具有提取效率高,净化效果好,回收率高,准确灵敏等优点,可应用于海洋沉积物中多氯联苯等持久性有机污染物残留的监测。     

电子废物拆解区农业土壤中多氯联苯的污染特征

用GC-μECD分析法测定了路桥表层土壤中144种多氯联苯同类物的含量.目的是了解该地区表层土壤中PCBs的污染水平、空间分布特征和来源.结果表明,样品中ΣPCBs为0.779～937 ng.g-1,均值为75.7 ng.g-1,研究区域中南部污染水平较高.同族体组成特征表明,38个样品组成以penta-CBs、hexa-CBs和tetra-CBs为主,含量范围分别为13.0%～61.1%、4.59%～48.8%和10.1%～31.5%;另外3个样品组成以di-CBs为主,范围为47.1%～75.2%.聚类分析表明,大多数样品主要受到Ar1254工业品的污染,少数样品的污染与Ar1221工业品有关.ΣPCBs与TOC显著相关,表明土壤中TOC的含量是影响PCBs在土壤中蓄积的重要因素之一;各PCBs同族体(除di-CBs与nona-CBs之间外)显著相关,表明各PCBs同族体有相似的输入途径.与国内外其它研究相比,研究区域表层土壤PCBs污染处于中高水平.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in different tissues of the cormorants (Phalacrocorax carbo) from Dongting Lake, China

Tissue distribution provides important information regarding the pharmacokinetic behavior of pollutants and is invaluable when analyzing the risk posed to avian species by the exposure to such kind of pollutants. In this study, concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in muscle, liver, spleen, kidney, stomach, gall bladder, skin, heart, pancreas, intestine and lung tissue extracts of cormorants collected from Dongting Lake, China. Tissue distribution results showed preferential accumulation of PCDD/Fs in both liver and skin. The total concentration of PCDD/Fs ranged from 421 to 5696 pg/g lipid weight. Octachlorinated dibenzo-p-dioxin (OCDD) was the predominant congener in all tissues and contributed between 31% and 82% to all 17 PCDD/Fs in different tissues. The liver/muscle ratios progressively increased with the degree of chlorination of PCDDs, except for OCDD. The relative toxic potential of PCDDs and PCDFs in tissues were calculated using the World Health Organization (WHO) Toxic Equivalency Factors (TEFs) for birds. The concentrations of WHO-toxic equivalent in different tissues ranged between 14.8 and 2021 pg/g lipid weight. These results indicated PCDD/Fs may have been bio-accumulated in cormorant via food-web. Furthermore, when compared with studies reported in the literatures, the PCDD/Fs levels in the cormorant collected from Dongting Lake were still relatively high.     

Distribution of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in surface water and sediments from Baiyangdian Lake in North China

Persistent organochlorine compounds, including hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and polychlorinated biphenyls (PCBs) were analyzed in surface water and sediments from Baiyangdian Lake, North China. Total concentrations of HCHs, DDTs and PCBs in surface water were in the range of 3.13-10.60, 4.05-20.59 and 19.46-131.62 ng/L, respectively, and total concentrations of HCHs, DDTs and PCBs in sediments were 1.75-5.70, 0.91-6.48 and 5.96-29.61 ng/g dry weight, respectively. Among the groups of HCHs (sum of α-HCH, β-HCH, γ-HCH and δ-HCH) and DDTs (sum of DDT, DDD and DDE), the predominance of β-HCH, DDE and DDD in water and sediment samples was clearly observed. This observation suggested that β-HCH was resistant to biodegradation and the DDTs had been transformed to its metabolites, DDE and DDD. For PCBs, penta-, hexa- and hepta-chlorinated congeners were the most abundant compounds in the both phases. Furthermore, the partitioning of chlorinated compounds between sediment and water was investigated to understand their transport and fates in aquatic ecosystems. The results indicated that average logs of organic carbon-normalized sediment-water partition coefficients (logK_oc') for OCPs varied between 3.20 and 5.53, and for PCBs, logK_oc' values ranged from 3.19 to 5.57. The observed logK_oc' was lower than their equilibrium logK_oc predicted from linear model, which may be attributed to the solubility enhancement effect of colloidal matter in water phase and the disequilibrium between sediment and water.