超临界流体萃取脱除人参中痕量有机氯农药

The feasibility of removal of the organochlorine pesticides residues of hexachlorocyclohexane(BHC) from radix ginseng with supercritical CO2 was explored. Some factors, such as extraction pressure, extraction temperature, and kinds of co-solvents were investigated. The experimental results indicate that it is possible to reduce BHC residues in radix ginseng to the level of 0.1×10-6 with supercritical CO2 in the presence of suitable amount of co-solvent, such as water.     

Exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish

Persistent organic pollutants (POPs) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially POPs categorized as organohalogen contaminants (OHCs). OHCs have been of concern in the circumpolar arctic for decades. For example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated PCBs, DDTs and CHLs) and emerging (e.g., brominated flame retardants (BFRs) and in particular polybrominated diphenyl ethers (PBDEs) and perfluorinated compounds (PFCs) including perfluorooctane sulfonate (PFOS) and perfluorooctanic acid (PFOA) found in Arctic biota and humans. Of high concern are the potential biological effects of these contaminants in exposed Arctic wildlife and fish. As concluded in the last review in 2004 for the Arctic Monitoring and Assessment Program (AMAP) on the effects of POPs in Arctic wildlife, prior to 1997, biological effects data were minimal and insufficient at any level of biological organization. The present review summarizes recent studies on biological effects in relation to OHC exposure, and attempts to assess known tissue/body compartment concentration data in the context of possible threshold levels of effects to evaluate the risks. This review concentrates mainly on post-2002, new OHC effects data in Arctic wildlife and fish, and is largely based on recently available effects data for populations of several top trophic level species, including seabirds (e.g., glaucous gull (Larus hyperboreus)), polar bears (Ursus maritimus), polar (Arctic) fox (Vulpes lagopus), and Arctic charr (Salvelinus alpinus), as well as semi-captive studies on sled dogs (Canis familiaris). Regardless, there remains a dearth of data on true contaminant exposure, cause-effect relationships with respect to these contaminant exposures in Arctic wildlife and fish. Indications of exposure effects are largely based on correlations between biomarker endpoints (e.g., biochemical processes related to the immune and endocrine system, pathological changes in tissues and reproduction and development) and tissue residue levels of OHCs (e.g., PCBs, DDTs, CHLs, PBDEs and in a few cases perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonates (PFSAs)). Some exceptions include semi-field studies on comparative contaminant effects of control and exposed cohorts of captive Greenland sled dogs, and performance studies mimicking environmentally relevant PCB concentrations in Arctic charr. Recent tissue concentrations in several arctic marine mammal species and populations exceed a general threshold level of concern of 1 part-per-million (ppm), but a clear evidence of a POP/OHC-related stress in these populations remains to be confirmed. There remains minimal evidence that OHCs are having widespread effects on the health of Arctic organisms, with the possible exception of East Greenland and Svalbard polar bears and Svalbard glaucous gulls. However, the true (if any real) effects of POPs in Arctic wildlife have to be put into the context of other environmental, ecological and physiological stressors (both anthropogenic and natural) that render an overall complex picture. For instance, seasonal changes in food intake and corresponding cycles of fattening and emaciation seen in Arctic animals can modify contaminant tissue distribution and toxicokinetics (contaminant deposition, metabolism and depuration). Also, other factors, including impact of climate change (seasonal ice and temperature changes, and connection to food web changes, nutrition, etc. in exposed biota), disease, species invasion and the connection to disease resistance will impact toxicant exposure. Overall, further research and better understanding of POP/OHC impact on animal performance in Arctic biota are recommended. Regardless, it could be argued that Arctic wildlife and fish at the highest potential risk of POP/OHC exposure and mediated effects are East Greenland, Svalbard and (West and South) Hudson Bay polar bears, Alaskan and Northern Norway killer whales, several species of gulls and other seabirds from the Svalbard area, Northern Norway, East Greenland, the Kara Sea and/or the Canadian central high Arctic, East Greenland ringed seal and a few populations of Arctic charr and Greenland shark.     

Concentrations and determinants of organochlorine levels among pregnant women in Eastern Spain

Persistent organic pollutants (POPs) comprise a large variety of toxic substances with ample distribution. While exposure to these toxins occurs mainly through diet, maternal POP levels may be influenced by certain sociodemographic, environmental, or lifestyle factors. This is important given that these substances may have adverse effects on fetal development. The aim of this study is to examine the sociodemographic, environmental, lifestyle, and dietary determinants of the levels of hexachlorobenzene (HCB), b-hexachlorocyclohexane (b-HCH), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (4,4′-DDT), 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (4,4′-DDE), and polychlorinated biphenyls (PCB congeners 118, 138, 153, 180) measured in the blood of pregnant women participating in a mother-child cohort study conducted in Valencia (Spain).The study population consisted of 541 pregnant women who formed part of the INMA (Childhood and the Environment) cohort (2004-2006). POP levels were determined in blood taken during the 12th week of pregnancy with the aid of gas chromatography with electron capture detection. Sociodemographic, environmental, and dietary information was obtained from a questionnaire. Multivariate Tobit regression models were constructed in order to assess the association between POP levels and selected covariates.The results showed that all the women had detectable levels of at least one of these compounds while in 43% of the subjects, all eight compounds were detected. The compounds found in the greatest number of women were 4,4′-DDE (100%) and PCBs 153 and 180 (95%). The most important determinants of high POP levels were the mother's age, country of origin, increased body mass index, and number of weeks of breastfeeding after previous pregnancies. With regard to diet, 4,4′-DDT and 4,4′-DDE levels increased with the intake of meat, fruit, and cereal. PCB 153 levels increased with the intake of seafood. The levels of HCB, b-HCH, 4,4′-DDT, and 4,4′-DDE observed in this study were slightly higher than in other studies, whereas the PCB levels were similar.     

分散固相萃取-气相色谱法测定大米中六六六 和滴滴涕残留量

目的 建立气相色谱-电子捕获检测器法(GC-ECD)测定大米中六六六和滴滴涕(α-六六六、β-六六六、γ-六六六、δ-六六六、o, p’-滴滴滴、o, p’-滴滴伊、o, p’-滴滴涕、p, p’-滴滴滴、p, p’-滴滴伊、p, p’-滴滴涕)残留量的方法。方法 大米样品经乙腈超声提取后,应用PSA进行分散固相萃取净化,高速离心后氮吹浓缩定容,最后使用气相色谱电子捕获检测器测定。结果 六六六和滴滴涕在0.002~0.1 mg/L浓度范围内呈现良好线性关系,R2大于0.99;在0.002、0.005、0.01 mg/kg三个添加浓度上回收率范围为84.10%~111.43%,相对标准偏差小于9.23%,检出限在0.0001~0.0007 mg/kg。结论 该方法前处理操作快速简单,重复性好且灵敏度高,满足国内外对大米中六六六和滴滴涕快速、准确检测的要求,可应用于大量样品的定性定量分析。     

Full‐scale in situ bioremediation of hexachlorocyclohexane‐contaminated soil

Daramend bioremediation technology was used to treat 1100 tonnes of hexachlorocyclohexane (HCH)‐contaminated soil at a former lindane manufacturing plant. Half of the site (area A) was treated using a cycled anoxic/oxic treatment, and the other half (area B) was treated under oxic conditions. Each area was divided east to west into five zones. A control area (area C) consisted of strips of soil along the north and east edges of the site. Total HCH concentrations along a west to east gradient ranged from 22 430 to 1069 mg kg^?1 in area A and from 21 100 to 730 mg kg^?1 in area B. Concentrations in area C ranged from 52 to 1427 mg kg^?1. The soil was treated for 371 days, during which time seven anoxic/oxic cycles were completed in area A and regular tillage was performed on area B. Soil samples (one per zone) were collected after 154 and 371 days of treatment. After 371 days, total HCH concentrations were reduced in the most highly contaminated zones of areas A and B by 60% (from 22 430 to 8910 mg kg^?1) and 75% (from 21 100 to 5120 mg kg^?1), respectively. The average HCH reductions for all five zones of areas A and B were 40 and 47%, respectively, with the data indicating decreased concentrations of selected isomers in certain zones of both areas. Less substantial changes in HCH concentrations were observed in control area C. Elevated chloride ion concentrations were observed in zones that had demonstrated HCH removal. This full scale project demonstrated the potential for solid phase bioremediation treatment of soil containing high HCH concentrations. Copyright © 2005 Society of Chemical Industry     

Effect of surfactants on the soil desorption of hexachlorocyclohexane (HCH) isomers and their anaerobic biodegradation

The extensive utilization of hydrophobic organic compounds (HOCs) such as pesticides generates high environmental pollution levels. Due to their hydrophobicity, this type of compound tends to accumulate in soil organic matter and, thus, soil desorption limits their availability for microbial degradation. The use of surfactants may increase the pollutant's desorption from the soil. One of the pesticides with strong sorption characteristics is hexachlorocyclohexane (HCH), a mixture of isomers: α‐, β‐, γ‐ and δ‐HCH. In this work, we evaluated the use of three surfactants, Triton X100, Tween 80 and sodium dodecyl sulfate (SDS), on the HCH desorption from a sandy loam soil. The effects of the addition of these surfactants on anaerobic biodegradation were studied. To attain this purpose, different assays were performed to evaluate both effects. Triton X100 exerted the best desorption of HCH isomers, followed by Tween 80, whereas SDS caused no significant desorption of the isomers. Triton had a strong inhibitory effect on the HCH biodegradation, while Tween 80 did not decrease the degradation rates of the different isomers. Moreover, the degradation rates of β‐ and δ‐HCH were significantly enhanced (around 10%). On the other hand, detrimental effects on the biodegradation rates and yields were due to the ageing of the soil, depending on the period of exposure of the soil to the pollutant. Copyright © 2005 Society of Chemical Industry     

米粉中六六六农药残留测定的能力验证研究

目的设计组织米粉中六六六测定能力验证项目,评价食品检验机构对有机氯农药残留的检测能力。方法制备单一水平样品,对参加实验室米粉中六六六测定结果进行稳健统计分析,以稳健Z比分数评价实验室检测能力,对实验操作记录进行技术分析。结果在95%置信水平下,样品均匀性符合要求,且至少在2个月内保持稳定,满足能力验证计划要求。42家实验室参加了本次计划,满意结果数为30家,满意率为71.4%。结论多数参加实验室对六六六农药残留检测结果满意,部分实验室检测能力有待提高。     

哈尔滨郊区池塘养殖鱼类六六六和滴滴涕残留特征及食用健康风险

目的 明确哈尔滨郊区池塘养殖鱼类六六六(HCHs)和滴滴涕(DDTs)的残留水平及食用安全性。方法 以4种养殖鱼类(鲤、鲢、鲶和草鱼)为研究对象,采用气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry, GC-MS)分析了49份鱼类样品的背肌、腹肌、肝脏、皮和鳃中HCHs和DDTs的残留水平,并对其可食部分进行致癌与非致癌风险评价。结果 HCHs和DDTs在鱼体各组织中残留量分别为0.299~12.881 μg/kg和0.012~1.439 μg/kg,均低于GB 2763—2021《食品安全国家标准 食品中农药最大残留限量》中规定的限量标准(DDTs≤500 μg/kg和HCHs≤100 μg/kg)。在背肌、腹肌和皮中,HCHs和DDTs残留量最高的均是鲶,鲢最低,而且背肌残留水平高于腹肌,HCHs的残留量大于DDTs。鱼体中残留的HCHs异构体组成以γ-六六六为主,贡献率在80.24%~95.82%,其次是α-六六六。食用该养殖鱼类导致的HCHs和DDTs每日摄入量分别为3.433~10.751 ng/(kg·d)和0.213~1.420 ng/(kg·d),均低于参考剂量(reference dose, RfD),致癌风险指数(carcinogenic risk index, CRI)在10-7~10-5,存在一定的潜在致癌风险;非致癌风险指数(non-carcinogenic hazard index, HI)均小于1,在可接受水平。结论 尽管HCHs和DDTs已被禁用多年,仍可在养殖鱼类体内检测到,但其残留水平低于国家限量标准,对人群无明显的食用健康风险。     

基质固相分散萃取-气相色谱法测定罗汉果中六六六、滴滴涕

目的 建立罗汉果中六六六、滴滴涕的基质固相分散萃取(MSPD)-气相色谱(GC)分析方法。方法 采用基质固相分散萃取技术作为前处理方法, 用气相色谱法进行快速定性定量分析。结果 八种有机氯农药的添加回收率在75.1%~112.4%之间, 相对标准偏差为2.1%~12.4%之间。基质固相分散萃取将提取、过滤和净化一步完成, 简化了传统样品的前处理过程, 缩短了时间, 节省溶剂, 也减少了对环境的污染。结论 该方法作为罗汉果中的六六六、滴滴涕有机氯农药残留的快速检测新方法, 基本能满足国内以及国际对农药残留分析质量控制要求。