Hg-CEMS系统中元素汞发生器的溯源和质控方法研究

参考借鉴美国IEMGTP元素汞溯源协议中规定的4个溯源传递层级以及4种常用的成熟溯源质控方法，研究了在中国现有技术条件下，各种质控方法针对Hg-CEMS中元素汞发生器User generator进行质控的适用性。通过对不同质控方法的测试，显示通过可吸附元素汞的活性炭吸附管采样分析（美国EPA 30B方法）和通过汞渗透源两种对元素汞发生器进行质控的方法在中国目前是可行且科学、可靠的。同时对建立和完善中国的元素汞溯源协议和元素汞发生器质控方法提出了建议。     

氢化物发生-原子吸收光谱法测定水中汞

环境样品种类广 ,测定项目多。因此 ,挖掘实验室现有仪器的潜力 ,对监测分析至关重要。今利用现有的氢化物发生装置代替汞还原器 ,完成了原子吸收光谱法对环境诸多水样中痕量汞的测定。这种重新组合的方法[1],有着同样高的灵敏度和准确性。1　试验1 1　主要仪器和试剂ＰＥ 1 1 0 0Ｂ型原子吸收光谱仪 ;ＭＨＳ - 1 0氢化物发生装置 ;汞标准溶液 :临用时 ,将 1 0 0ｍｇ/Ｌ汞标准贮备液用稀释溶液逐级稀释至 0 1 0 0ｍｇ/Ｌ汞标准溶液 ;稀释溶液 :称取 0 2 ｇ重铬酸钾溶于90 0ｍＬ水中 ,加入浓硝酸 50ｍＬ ,稀释至1 0 0 0ｍＬ ;2 0 ｇ/ＬＮ…     

施工扬尘环境下短时强降雨屋面径流中砷、汞、铅、镉、锌的污染特征研究

以南京北郊为例,测量分析了屋面径流中砷(As)、汞(Hg)、铅(Pb)、镉(Cd)和锌(Zn)5种元素的浓度、形态特征。结果表明:短时强降雨过程中这5种元素浓度在较大范围内无规则波动,且不同元素间浓度分布存在较大差异;Zn与Pb的平均浓度分别高于《地表水环境质量标准》(GB 3838—2002)的Ⅴ类和Ⅳ类标准限值,污染程度从大到小依次为ZnPbAsHgCd。元素形态分析表明,径流中除Hg外其他4种元素主要以颗粒态形式存在,各元素颗粒态占总形态的平均分数分别为:As,64.5%;Hg,43.7%;Pb,76.5%;Cd,54.6%;Zn,54.3%。     

新试剂5—（3—甲基—2—吡啶）亚甲基若丹宁光度法测定汞的研究

研究了新试剂5-（3-甲基-2-毗啶）亚甲基若丹宁（MPMR）与汞的显色反应，在弱酸性介质中和CTMAB微乳液存在下，MPMR与Hg2 生成2：1稳定络合物，λmax=445nm，ε=1.04X105L.mol－1.cm－1。汞的含量在0～1．2mg几内符合比耳定律。方法用于水样中汞的测定，结果满意。     

三峡库区柑橘对土壤重金属吸收富集特征研究

研究区域柑橘果实重金属含量符合NY/T 426-2000<绿色食品柑橘>标准,果实品质达到一级产品.土壤中重金属的含量越高,柑橘叶片、果皮、果肉的重金属含量也越高.柑橘叶片对土壤重金属铜、锌、铅、镉、镍、汞、砷、铬的吸收富集能力显著大于果皮与果肉,果皮对土壤重金属铜、锌、铅、镉、汞的吸收富集能力显著大于果肉,果肉对土壤重金属铬的吸收富集能力显著大于果皮.柑橘同一部位对土壤中不同重金属元素的吸收富集能力也存在很大的差异,柑橘叶片对土壤中不同重金属元素的富集系数大小顺序为Hg＞Pb＞Cd＞Cu＞Zn＞Cr＞As＞Ni,柑橘果皮对土壤中不同重金属元素的富集系数大小顺序为Cd＞Hg＞Cu＞Zn＞Pb＞Cr＞Ni＞As,柑橘果肉对土壤中不同重金属元素的富集系数大小顺序为Hg＞Cu＞Cr＞Zn＞Cd＞Ni＞Pb＞As.     

水样中痕量汞的分光光度法测定

研究了在表面活性剂 Triton X-1 0 0存在下 ,2 ,6—二溴— 4—羧基苯重氮氨基偶氮苯与 Hg2 +的显色反应 ,建立了简便快速测定水样中痕量汞的方法。在 p H为 9.1 0～ 1 0 .2 0时 ,试剂与 Hg2 +形成的配合物的最大吸收峰位于 51 0 nm,Δλ =1 1 0 nm。当汞量在 0～ 1 .0 mg/ L时 ,吸光度与汞量呈线性关系 ,摩尔吸光系数ε=1 .50× 1 0 5 L·mol- 1 · cm- 1 ,并将该法成功地运用于环境水样中汞的测定。     

金膜吸附-冷原子吸收光谱法测定空气中的汞

采用新型金膜吸附-冷原子吸收光谱法测定空气中的汞，在0μg/L～100μg/L范围内线性良好，相关系数为0．9991。方法检出限为1．6 ng/m3，RSD为0．5％～2．7％，测定两种不同浓度的汞标准样品，相对误差为6．1％和3．2％。与两种现行国标方法（巯基棉富集和高锰酸钾溶液吸附法）比较，该方法所需试剂种类少，操作简便、吸附效率好，加标回收率高。     

燃煤电厂煤中汞含量对烟气中汞排放水平的影响

对江苏省9家燃煤电厂入炉煤中ω（汞）及烟气中ρ（汞）进行了测试，结果表明，9家燃煤电厂入炉煤中ω（汞）为54．5～297 ng／g，平均值为139 ng／g，低于我国煤中ω（汞）的平均值（220 ng／g）。燃煤电厂排放烟气中ρ（汞）为0．08～16．97μg／m^3，远低于《火电厂大气污染物排放标准》（GB 13223－2011）汞及其化合物标准限值（30μg／m^3）。通过对燃煤电厂入炉煤中ω（汞）与最终排放的烟气中ρ（汞）进行分析，两者之间有一定的相关性。     

气体中痕量汞的富集与测定

大气中汞含量通常可直接使用测汞仪进行检测。当要求气体中汞含量低于2微克/米~3时就要预先富集。目前国内多用传统的高锰酸钾——硫酸溶液进行富集。但我们在长期实践中认为用金、银与汞形成汞齐的方法与二氧化锰富集法互相配合使用较为适宜。其特点是环境适应性强、携带方便且取样后可在较长时间内保存。本文用上述两种富集方法以冷原子吸收法和冷原子荧光法进行试验,同时自制一个适于汞分析试验用的“稳恒连续汞蒸气发生器”,效果较好。     

改进吡啶—巴比妥酸比色法快速测定水中氰化物

文献 [1 ]中规定采用吡啶—巴比妥酸比色法测定水中的氰化物时 ,需要在 40℃水浴中显色2 0ｍｉｎ ,现改用在 2 0℃水浴中显色 1 0ｍｉｎ进行氰化物的测定 ,经对比实验 ,通过水样测试发现两者测定值无显著差别。1　对比实验1 1　不同浓度标准溶液对比实验各取 0 5ｍｇ/Ｌ～ 6 0ｍｇ/Ｌ———系列氰化物标准使用液 ,分别在 40℃水浴中显色 2 0ｍｉｎ(简称原方法 )和在 2 0℃水浴中显色 1 0ｍｉｎ(简称新方法 )测定其吸光值 (Ａ) ,结果如下表 1。表 1　不同浓度标准溶液对比分析结果　　　Ａ试验方法 标准溶液浓度　ｃ/ (ｍｇ·Ｌ-1)0 5 0 1…     

微波消解-ICP/MS法同时测定水产品中13种元素

用硝酸-双氧水体系微波消解，以In、Sc为内标，采用电感耦合等离子体质谱法（ICP／MS）同时测定水产品中V、Cr、C0、Ni、Cu、Zn、As、Se、Cd、Sb、Ba、T1、Pb等13种元素。各元素的检出限在0．05ng／g～0．064μg／g之间，样品平行测定4次的RSD〈5％，鲢鱼样品的加标回收率在81％～117％之间。     

基于燃煤电厂超低排放的汞分布特性研究

为掌握超低排放改造后烟气处理装置对汞分布的影响,选择6台有代表性的超低排放火电机组进行现场测试。通过对火电机组入炉煤、炉渣、飞灰、脱硫石膏、末端烟气等样品的测试,得出不同燃烧产物中汞的分布:底渣和湿除出水的汞含量极微;电除尘底灰中的汞所占比重相对较大,平均汞含量占燃烧产物中总汞的比例可达57.97%。依据质量平衡原理,计算出不同超低排放改造工艺路线对汞的协同脱除效率为87.26%~95.60%,并分析了不同污染控制设备对汞排放的影响。     

灵宝市金矿选冶区土壤汞的地统计分析及污染评价

利用数理统计、地统计方法和地理信息系统(GIS)技术研究了灵宝市的金矿选冶区土壤汞的空间分布特性和污染程度评价。Hg和Cu、Zn、Pb、Cd重金属元素存在较大的偏度和峰度,为了使这些元素的数据服从正态分布并降低其偏度和峰度,采用了Box-Cox变换。地统计分析认为研究区内土壤Hg元素具有空间结构特性。用普通克里格插值绘制的研究区Hg含量地球化学图体现了其空间分布特征。结合地累积指数法评价指标得出的研究区Hg污染等级分布图为土壤恢复治理提供了一定科学依据。     

Application of cryofocusing hydride generation and atomic fluorescence detection for dissolved mercury species determination in natural water samples

The concentration levels of mercury (Hg) species in natural water samples are usually low. Consequently, accurate analysis with low detection limits is still a major problem. In this work, a method was applied for the simultaneous direct determination of dissolved mercury species in water samples by on-line hydride generation (HG), cryogenic trapping (CT), gas chromatography (GC) and detection by atomic fluorescence spectrometry (AFS). The suitability of the method for real samples with different organic matter and chloride contents was evaluated by recovery experiments in synthetic and natural spiked water samples. The HG method was compared with other current available methods for mercury analysis with respect to the different fraction of mercury analysed, i.e. 'reactive', 'reducible' or total. HG derivatization and SnCl2 reduction (with and without previous oxidation with BrCl) were applied to synthetic and natural (spiked and non-spiked) water samples. The influence of chloride and dissolved organic matter concentrations was studied. The results suggest that the HG procedure is suitable for the simultaneous determination of Hg2+ and MeHg+ in surface water samples. Inorganic mercury analysed by HG (i.e. reducible) is close to the total inorganic mercury.     

活性炭负载催化剂去除燃煤烟气中单质汞的研究

以贵州凯里褐煤进行燃烧实验,研究采用CoCl2(负载量20%)改性的活性炭去除烟气中的单质汞。颗粒态汞占烟气总汞的87%,而单质汞占气态汞的80.4%。改性活性炭吸附了气态汞中97%的单质汞,而吸收液只吸收了3%的单质汞。可见改性活性炭也能有效地吸附煤燃烧实验中的烟气汞。实验结果表明,煤中汞的释放率为59.5%,1kg的改性活性炭可以吸附208t煤所产生的烟气中的气态单质汞。     

Assessment of dissolved heavy metal in the Yangtze River estuary and its adjacent sea, China

The purpose of this paper is to determine the concentrations of dissolved heavy metals namely mercury (Hg), lead (Pb), cadmium (Cd), and copper (Cu) and to investigate the relationships between nutrients (nitrate-nitrogen and phosphate) and dissolved heavy metals. For this purpose, the concentrations of dissolved heavy metals were measured through 51 voyages form 1984 to 2006 in the Yangtze river estuary and its adjacent sea. Results analysis showed that dissolved heavy metals were not the main pollutants in the Yangtze river estuary, and the main source of heavy metal contamination was industrial wastewater from terrestrial pollution during the past 20 years. Heavy metal values showed significant abundance in the south branch of the Yangtze River estuary and Hangzhou Bay. In addition, Pb showed negative correlation with nutrients, while the positive correlations between Hg, Cd, and nutrients were shown. The obtained molar ratios, $\Delta \mbox{Cd}/\Delta \mbox{N} = 1.68 \times 10^{-5}$ and $\Delta \mbox{Cd}/\Delta \mbox{P} = 1.66 \times 10^{-4}$ , are close to those in plankton, showing the biogeochemical behavior and process of dissolved cadmium.     

HPLC-ICP/MS联用测定废水中甲基汞和无机汞

采用高效液相色谱(HPLC)-电感耦合等离子体质谱(ICP/MS)联用测定废水中可滤态的甲基汞和无机汞,优化了仪器工作条件,讨论了方法干扰及校正办法。甲基汞和无机汞在0.500μg/L~25.0μg/L范围内线性良好,检出限分别为0.03μg/L和0.07μg/L,废水样品平行测定的RSD分别为6.5%~7.6%和6.2%~6.8%,加标回收率分别为84.0%~87.0%和88.0%~92.4%。     

巯基葡聚糖凝胶分离富集二溴邻硝基偶氮胂分光光度法测定汞 (Ⅱ)

研究了溴代十六烷基吡啶、正丁醇、正庚烷和水自制微乳溶液介质中，汞（Ⅱ）与二溴邻硝基偶氮胂的显色反应，采用巯基葡聚糖凝胶分离共存离子并富集汞（Ⅱ），建立了分光光度法测定微量汞（Ⅱ）的新方法。在pH值为6．00的乙酸-乙酸钠缓冲溶液中，汞（Ⅱ）与试剂形成紫红色络合物，其最大吸收峰位于530nm波长处，表观摩尔吸光系数8为3．3×10^5L／（mol·cm）。在显色液中汞（Ⅱ）质量浓度在8．00μg／L～600μg／L范围内符合比尔定律，检出限为0．003mg／L，水、牛奶、化妆品测定的RSD为1．4％～6．1％，加标回收率为96．8％～105％。     

Predominant anthropogenic sources and rates of atmospheric mercury accumulation in southern Ontario recorded by peat cores from three bogs: comparison with natural "background" values (past 8000 years)

Peat cores from three bogs in southern Ontario provide a complete, quantitative record of net rates of atmospheric Hg accumulation since pre-industrial times. For comparison with modern values, a peat core extending back 8000 years was used to quantify the natural variations in Hg fluxes for this region, and their dependence on climatic change and land use history. The net mercury accumulation rates were separated into "natural" and "excess" components by comparing the Hg/Br ratios of modern samples with the long-term, pre-anthropogenic average Hg/Br. The average background mercury accumulation rate during the pre-anthropogenic period (from 5700 years BC to 1470 AD) was 1.4 +/- 1.0 microg m(-2) per year (n = 197). The beginning of Hg contamination from anthropogenic sources dates from AD 1475 at the Luther Bog, corresponding to biomass burning for agricultural activities by Native North Americans. During the late 17th and 18th centuries, deposition of anthropogenic Hg was at least equal to that of Hg from natural sources. Anthropogenic inputs of Hg to the bogs have dominated continuously since the beginning of the 19th century. The maximum Hg accumulation rates decrease in the order Sifton Bog, in the City of London, Ontario (141 microg Hg m(-2) per year), Luther Bog in an agricultural region (89 microg Hg m(-2) per year), and Spruce Bog which is in a comparatively remote, forested region (54 microg Hg m(-2) per year). Accurate age dating of recent peat samples using the bomb pulse curve of 14C shows that the maximum rate of atmospheric Hg accumulation occurred during AD 1956 and 1959 at all sites. In these (modern) samples, the Hg concentration profiles resemble those of Pb, an element which is known to be immobile in peat bogs. The correlation between these two metals, together with sulfur, suggests that the predominant anthropogenic source of Hg (and Pb) was coal burning. While Hg accumulation rates have gone into strong decline since the late 1950's, Hg deposition rates today still exceed the average natural background values by 7 to 13 times.