Sulfur speciation and bioaccumulation in camphor tree leaves as atmospheric sulfur indicator analyzed by synchrotron radiation XRF and XANES

Analyzing and understanding the effects of ambient pollution on plants is getting more and more attention as a topic of environmental biology.A method based on synchrotron radiation X-ray fluorescence and X-ray absorption near edge structure spectroscopy was established to analyze the sulfur concentration and speciation in mature camphor tree leaves (CTLs),which were sampled from 5 local fields in Shanghai,China.Annual SO2 concentration,SO42-concentration in atmospheric particulate,SO42-and sulfur concentration in soil were also analyzed to explore the relationship between ambient sulfur sources and the sulfur nutrient cycling in CTLs.Total sulfur concentration in mature camphor tree leaves was 766-1704 mg/kg.The mainly detected sulfur states and their corresponding compounds were +6 (sulfate,include inorganic sulfate and organic sulfate),+5.2 (sulfonate),+2.2 (suloxides),+0.6 (thiols and thiothers),+0.2 (organic sulfides).Total sulfur concentration was strongly correlated with sulfate proportion with a linear correlation coefficient up to 0.977,which suggested that sulfur accumulated in CTLs as sulfate form.Reduced sulfur compounds (organic sulfides,thiols,thioethers,sulfoxide and sulfonate) assimilation was sufficed to meet the nutrient requirement for growth at a balanced level around 526 mg/kg.The sulfate accumulation mainly caused by atmospheric sulfur pollution such as SO2 and airborne sulfate particulate instead of soil contamination.From urban to suburb place,sulfate in mature CTLs decreased as the atmospheric sulfur pollution reduced,but a dramatic increase presented near the seashore,where the marine sulfate emission and maritime activity pollution were significant.The sulfur concentration and speciation in mature CTLs effectively represented the long-term biological accumulation of atmospheric sulfur pollution in local environment.     

典型电子拆解地两种指示生物监测重金属污染的对比研究

利用ICP-MS定量测定了温岭市电子垃圾拆解地区的大灰藓及樟树叶中的12种金属元素的含量,对比分析了两种指示生物对不同金属元素的富集情况.结果显示,不同地区样品中的所有金属含量呈现污染区对照区的趋势,其中苔藓中As、Cr、Mn、Se、V和Cd,樟树叶中Cr、Cu、Ni、Se、Sb和Cd的含量呈现重污染区轻度污染区对照区的趋势.拆解区中樟树叶中除Mn以外的金属总含量(所有金属含量之和)要低于苔藓.除Mn、Cr和Se以外的其它9种金属在苔藓中的含量要显著高于樟树叶中的金属含量(p0.05),但苔藓中金属含量的标准偏差要大于樟树叶.由污染因子(pollution factor)的结果表明苔藓及树叶样品中的金属Sn、Sb及Cd的污染因子最高;另外,研究通过比较树叶样品的不同预处理过程对最终含量测定的影响,发现经超纯水清洗的树叶样品中所有金属浓度要明显低于未经清洗的样品,并且标准偏差较低,数值稳定性好.主成分分析结果表明,Co、Cr、Ni、Pb、Sn及Cd为密切相关的一类元素,主要来源于电子废弃物拆解行为,而Mn、As及Se为第二类元素,主要来源于地质因素.     

苏南地区香樟树皮中有机氯农药(OCPs)的污染水平及来源解析

利用树皮作为被动采样介质,2012年8月于苏南地区采集了33个香樟树皮进行有机氯农药(OCPs)的分析.结果表明,苏南地区香樟树皮中六氯苯(HCB)、滴滴涕(DDTs)和氯丹(Chlordanes)的含量范围(以干重计)分别为0.31~1.81、0.40~17.3和n.d.~1.03 ng·g-1.由于六氯苯挥发性较强,其含量的空间差异性不明显.同其它研究结果相比,苏南地区树皮中六氯苯含量相对较低.苏南地区DDT主要来源于工业DDT的历史残留和三氯杀螨醇的使用.根据反式氯丹(TC)/顺式氯丹(CC)的比值判定,苏南地区城区中氯丹可能来源于近期的直接使用,而乡村地区则来源于历史残留.     

固上顶空气相色谱法测定樟脑和萘

本文对固上顶空气相色谱法的理论和测定条件进行了研究。用于樟脑和萘的测定，最小检出量达１０－９ｇ，回收率为９６．０～１０１．３％．本法基体干扰小，操作简便．     

湖北樟油化学资源

湖北省是中国樟油的重要产区之一。应用GC／MS技术，分析了湖北各种樟油的化学组成，共鉴定出108个化合物；经植物化学分类研究，发现湖北樟油的主要化学类型，现知共有12个；对于每个化学类型主成分的经济用途和应用价值，分别作出了比较分析与评述。报道了各类型樟油的产地，生态环境和物理性质。这些研究成果为湖北樟油资源的合理开发利用和保护提供了科学依据。     

微波催化氧化樟脑废水

在活性炭与Fenton试剂存在下用微波辐射处理多次铁碳微电解处理后的樟脑废水,通过单因素和正交试验,得出了100mL微波处理废水的最佳条件:活性炭为0.6g,H2O2为1.4mL,pH值取4,微波加热时间为15min,辐射功率为350W,可以使樟脑废水的COD值从321.4mg/L降到145.2mg/L。     

江苏经济高速发展城市香樟树皮中的多溴联苯醚

2009年7月在江苏省南部城市苏州,南通和无锡采集了40组香樟树皮样品,用加速溶剂萃取、气相色谱质谱法测定了样品中8种多溴联苯醚（PBDEs）.结果表明,所有样品中都检出了PBDEs,Σ8 PBDEs（BDE28、47、100、99、153、154、183、209）平均含量为835μg/kg脂重（112～7 460μg...     

我国苏南地区香樟树皮赋存的二英类污染特征及来源

为分析长江下游经济高速发展区的POPs污染特征,于2012年8月在苏南地区典型城市10个采样点采集香樟树皮,应用高分辨气相色谱-高分辨质谱(HRGC-HRMS)联用技术对二英(PCDD/Fs)浓度水平进行监测,同时采用主成分分析(PCA)法探讨其可能来源. 结果表明:苏南地区香樟树皮中二英的毒性当量(I-TEQ)浓度(以干质量计,下同)为5.6～12.2 pg/g,平均值为7.2 pg/g;4～8氯代二英同族体质量分数(以干质量计)范围为418～938 pg/g,平均值为635 pg/g. 由于二英在大气中的长距离迁移潜力较强,在研究的苏南地区区域尺度上,其含量在城市中心区和对照区之间的差异性并不明显;苏南地区香樟树皮二英质量分数及毒性当量浓度均高于国外报道的背景区及典型城市中树皮的水平. 对比典型二英排放源及树皮中二英特征谱图,可推断苏南地区香樟树皮中二英可能主要来源于危险(医疗)废物焚烧、机动车尾气排放和工业燃烧源.      

Effects of four commonly used UV filters on the growth,cell viability and oxidative stress responses of the Tetrahymena thermophila

UV filters are increasingly used in sunscreens and other personal care products. Although their residues have been widely identified in aquatic environment, little is known about the influences of UV filters to protozoan. The growth inhibition effects, cell viability and oxidative stress responses of four commonly used UV filters, 2-ethylhexyl 4-methoxycinnamate (EHMC), benzophenone-3 (BP-3), 4-methyl-benzylidene camphor (4-MBC) and octocrylene (OC), to protozoan Tetrahymena thermophila were investigated in this study. The 24-h EC₅₀ values with 95% confidence intervals for BP-3 and 4-MBC were 7.544 (6.561–8.675) mg L⁻¹ and 5.125 (4.874–5.388) mg L⁻¹, respectively. EHMC and OC did not inhibit the growth of T. thermophila after 24 h exposure at the tested concentrations. The results of cell viability assays with propidium iodide (PI) staining were consistent with that of the growth inhibition tests. As for BP-3 and 4-MBC, the relatively higher concentrations, i.e. of 10.0 and 15.0 mg L⁻¹, could lead to the cell membranes impairment after 4 h exposure. With the increase of the exposure time to 6 h, their adverse effects on cell viability of T. thermophila were observed at the relatively lower concentration groups (1.0 mg L⁻¹ and 5.0 mg L⁻¹). In addition, it is noticeable that at environmentally relevant concentration (1.0 μg L⁻¹), BP-3 and 4-MBC could lead to the significant increase of catalase (CAT) activities of the T. thermophila cells. Especially for the BP-3, the oxidative injuries were further confirmed by the reduction of glutathione (GSH) content. It is imperative to further investigate the additive action of UV filters and seek other sensitive endpoint, especially at environmentally relevant concentration.     

基于热减量法2/1樟发射药安全贮存寿命预估

目的 预估2/1樟发射药的安全贮存寿命,建立一种基于加速热减量试验,利用热减量曲线和贝瑟洛特(Berthelot)方程预估其安全贮存寿命的方法。方法 首先对2/1樟发射药分别进行85、95、105、115 ℃下的加速热减量试验,获得样品在各个温度下不同加速时间的热减量数据。然后基于热减量曲线,得到2/1樟发射药在各个温度下的延滞期。最后利用各个温度下的半延滞期,根据Berthelot方程拟合得到2/1樟发射药安全贮存寿命预估模型。结果 根据其安全贮存寿命预估模型计算得到2/1樟发射药在30 ℃下的安全贮存寿命约为50.9 a。结论 预测结果与文献值接近,且试验时间比文献减少了近1/2,验证了该方法的有效性,可为2/1樟发射药或其他发射药的安全贮存寿命预估提供一种可行的技术途径。