Distribution and chemical speciation of arsenic in different sized atmospheric particulate matters

The distribution and chemical speciation of arsenic (As) in different sized atmospheric particulate matters (PMs), including total suspended particles (TSP), PM₁₀, and PM_2.5, collected from Baoding, China were analyzed. The average total mass concentrations of As in TSP, PM₁₀, and PM_2.5 were 31.5, 35.3, and 54.1 µg/g, respectively, with an order of PM_2.5 >PM ₁₀ > TSP, revealing that As is prone to accumulate on fine particles. Due to the divergent toxicities of different As species, speciation analysis of As in PMs is further conducted. Most of previous studies mainly focused on inorganic arsenite (iAs^III), inorganic arsenate (iAs^V), monomethylarsonate (MMA), and dimethylarsinate (DMA) in PMs, while the identification and sensitive quantification of trimethylarsine oxide (TMAO) were rarely reported. In this study, a high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry system was optimized for As speciation including TMAO in PMs. An anion exchange column was used to separate MMA, DMA and iAs^V, while a cation exchange column to separate TMAO and iAs^III. Results showed that iAs^V was the dominate component in all the samples, corresponding to a portion of 79.2% ± 9.3% of the total extractable species, while iAs^III, TMAO and DMA made up the remaining 21%. Our study demonstrated that iAs^III accounted for about 14.4% ± 11.4% of the total extracted species, with an average concentration of 1.7 ± 1.6 ng/m³. It is worth noting that TMAO was widely present in the samples (84 out of 97 samples), which supported the assumption that TMAO was ubiquitous in atmospheric particles.     

典型砒霜厂污染场地重金属污染特征及环境风险评价

以某个砒霜厂旧址为研究对象,分析场地的重金属污染特征。结果表明,该场地受到砷、铜、铅、镉和锌等重金属污染,其中,砷污染指标超过评价标准值达7 199倍;基于《展览会用地土壤环境质量评价标准(暂行)》条件下,采用RBCA模型计算砷、镉、铜、锌对人体健康的环境风险,结果表明,该场地砷超过了致癌风险指数标准限值-6(10)及非致癌危害商标准限值(1),说明砷具有很大的环境风险;采用IEUBK模型计算铅对人体的健康风险,结果表明,铅也具有一定的环境风险。因此,该污染场地在开发利用过程中需要对环境风险区域进行治理修复后才能使用。     

STUDIED THE OSCILLOSCOPIC POLAROGRAPHV ANALYSIS OF TRACE ARSENIC IN WATER

本方法叙述了用示波极谱法测定水与污水中的微量砷。水样中的有机砷和无机砷被高锰酸钾氧化生成砷酸,在支持电解质中测定。校准曲线范围为0～10.0μg/10ml,方法的相对标准偏差分别为4.7,2.9和2.1回收率范围为91.67%～105.88%。     

Methylated and thiolated arsenic species for environmental and health research——A review on synthesis and characterization

Hundreds of millions of people around the world are exposed to elevated concentrations of inorganic and organic arsenic compounds, increasing the risk of a wide range of health effects. Studies of the environmental fate and human health effects of arsenic require authentic arsenic compounds. We summarize here the synthesis and characterization of more than a dozen methylated and thiolated arsenic compounds that are not commercially available. We discuss the methods of synthesis for the following14 trivalent(Ⅲ) and pentavalent() arsenic compounds: monomethylarsonous acid(MMA~Ⅲ), dicysteinylmethyldithioarsenite(MMA~Ⅲ(Cys)_2), monomethylarsonic acid(MMA~Ⅴ),monomethylmonothioarsonic acid(MMMTAⅤ) or monothio-MMA~Ⅴ, monomethyldithioarsonic acid(MMDTA~Ⅴ) or dithio-MMA~Ⅴ, monomethyltrithioarsonate(MMTTA~Ⅴ) or trithio-MMA~Ⅴ,dimethylarsinous acid(DMA~Ⅲ), dimethylarsino-glutathione(DMA~Ⅲ(SG)), dimethylarsinic acid(DMA~Ⅴ), dimethylmonothioarsinic acid(DMMTA~Ⅴ) or monothio-DMAⅤ, dimethyldithioarsinic acid(DMDTA~Ⅴ) or dithio-DMA~Ⅴ, trimethylarsine oxide(TMAO~Ⅴ), arsenobetaine(AsB), and an arsenicin-A model compound. We have reviewed and compared the available methods,synthesized the arsenic compounds in our laboratories, and provided characterization information. On the basis of reaction yield, ease of synthesis and purification of product, safety considerations, and our experience, we recommend a method for the synthesis of each of these arsenic compounds.     

饮用水砷污染治理研究进展

简述了饮用水中砷污染的来源和危害,砷在水环境的存在形态和毒性,分析了当前饮用水不同除砷方法的研究进展。     

土壤硒的生物有效性研究

对黑麦幼苗的试验表明,黑麦幼苗中的总硒(Se)浓度与总干重的乘积与0.1mol/L KH2PO4浸提态Se呈显著相关.对黑油菜的试验表明,在酸性土壤上,当Se(Ⅵ)的量≥0.5mg/kg时,可显著减少黑油菜的产量;而当Se(Ⅳ)的量达到2.0mg/kg时对产量影响不大;黑油菜吸收Se(Ⅵ)的量要大于吸收Se(Ⅳ)的量.通过田间采样分析表明,KH2PO4浸提态Se能反映土壤对植物的供Se状况,推荐用0.1mol/L KH2PO4溶液作为酸性土壤生物有效性Se的浸提溶液.影响土壤Se生物有效性的主要因子是CaCO3,其次是粉粒、有机质、黏粒含量.pH值可通过CaCO3对KH2PO4浸提态Se产生影响.     

杭州城市土壤重金属污染研究进展及展望

文章综述了杭州城市土壤重金属污染主要来源、重金属污染分布状况、重金属存在形态及相关性,并对下一步土壤重金属研究提出了展望。分析表明,杭州土壤重金属污染主要来源于工业"三废"排放、汽车尾气排放和农业化肥的施用。杭州对蔬菜地、茶园等农业用地、商业居住区、工业区附近土壤污染研究较多,对Cu、Pb和Zn等关注较多,而对Hg和As关注很少。城市土壤已受到一定程度的重金属污染,土壤中Cd、Cr、Cu、N i、Pb、Zn和Mn均有明显的积累,其浓度分布具有一定的地域差异,以工业区和商业区污染较重。土壤中Cd、Co、Cr、N i和Hg以稳定的残余态为主,而Cu、Pb、Zn和Mn以活性较高的非残余态为主,因杭州土壤呈中性偏碱性,正常情况下不会有明显的重金属释放。下一步应重点关注工业企业搬迁后场地重金属污染修复以及Hg和As的污染问题。     

基于GIS的宜宾城市土壤Pb含量空间分布特征及污染评价

基于ArcGIS地统计模块,对长江上游城市宜宾市的63个土壤样品进行了分析,探讨了城市土壤中重金属Pb的空间分布特征和污染状况.结果表明,城市土壤样品中Pb含量为20.3-223.9 mg·kg-1,平均含量为61.2 mg·kg-1,显著高于四川省土壤背景值,具有明显的累积效应(p=0);与四川省土壤基线值相比,宜宾...     

南京城市土壤Pb的含量及其化学形态

研究了南京城市土壤Pb的含量及其化学形态分布,结果表明:土壤全Pb平均含量为10.73mg/kg,变幅为36.3—472.6mg/kg,土壤Pb污染严重.表层土壤Pb以残渣态和铁锰氧化物结合态为主,各形态比例为残渣态>铁锰氧化物结合态碳酸盐结合态>有机结合态>可交换态.与非城区土壤比较,城市土壤中Pb不仅含量高,而且活性大,对环境危险性大.     

Rapid evaluation of arsenic contamination in paddy soils using field portable X-ray fluorescence spectrometry

Arsenic (As) in paddy fields is deteriorating food security and human health through rice ingestion. Rice is the dominant food source of arsenic exposure to half of the world''s population. Therefore, an in situ effective method for As risk evaluation in paddy soil is strongly needed to avoid As exposure through rice ingestion. Herein, we developed a rapid analytical methodology for determination of As in plant tissues using field portable X-ray fluorescence spectrometry (FP-XRF). This method was applied to rice roots in order to evaluate the As contamination in paddy soils. The results showed that rice roots with iron plaques were superior to rhizosphere soils for generating FP-XRF signals, especially for field sites with As concentrations lower than the soil detection limit of FP-XRF (30.0 mg/kg). Moreover, the strong linear relationships of As concentrations between the rice roots and corresponding leaves and grains proved that the rice root, rather than the soil, is a better predictor of As concentrations in rice grains. The research provides an efficient As monitoring method for As contaminated paddy fields by using wetland plant roots with iron plaques and XRF-based analytical techniques.