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1.
微波消解-化学蒸气发生-原子荧光光谱法同时测定铁矿石中的痕量砷和汞 总被引：1，自引：0，他引：1
采用HCl-HNO3混合酸(体积比1∶1)微波消解铁矿样品,在消解后的样品母液中直接加入硫脲-抗坏血酸,预还原五价砷为三价砷,消除铁和其他共存离子对砷、汞测定的干扰,采用化学蒸气发生-双道原子荧光光谱法同时测定铁矿石中的痕量砷和汞。结果表明5%的HCl-HNO3混合酸(体积比1∶1)、20 g/L硼氢化钾溶液能有效保证砷、汞双元素的同时测定,制备的砷、汞标准使用溶液在2～5℃下密闭保存,在245 d内具有稳定性。砷的检出限为0.085μg/L,汞的检出限为0.008μg/L。通过分析5个铁矿石有证标准物质,测定As的相对标准偏差为0.9%～5.5%,回收率为77.7%～105.4%,检测值与标准值吻合;测定Hg的相对标准偏差为1.1%～3.7%,回收率为86.2%～113.2%。本方法是以牺牲汞元素的检出限来实现砷、汞两元素的同时测定,是建立在砷、汞单独测定基础上的一种快速检测方法,经全国不同地区9家实验室采用5个标准样品进行协同实验验证,能够满足日常分析要求。 相似文献
2.
水浴浸提-氢化物发生-原子荧光光谱法同时测定地质样品中痕量砷和汞 总被引：2，自引：2，他引：0
采用盐酸-硝酸混合酸(盐酸-硝酸-水体积比3∶1∶4)水浴浸取地质样品,在样品消解后的母液中直接加入硫脲-抗坏血酸混合溶液,以氢化物发生-原子荧光光谱法同时测定地质样品中的痕量砷和汞。方法检出限为砷0.033 6 ng/mL,汞0.003 7 ng/mL;相对标准偏差(RSD,n=1)为砷1.1%,汞3.0%。对国家一级标准物质GBW 07109~GBW 07114、GBW 07301~GBW 07312、GBW 07401~GBW 07408中的砷和汞进行测定,测定值与标准值相吻合。 相似文献
3.
微波消解-氢化物发生原子荧光光谱法和质谱法测定高有机质无烟煤中汞砷的可行性研究 总被引：2，自引：2，他引：0
微波消解技术适用于处理大部分煤炭样品,但对于高有机质含量的无烟煤样品,因其煤化程度高,含有多种复杂的高分子有机化合物,应用现有的消解技术不能将其完全消解。本文对微波消解的实验条件包括消解试剂、消解温度及消解时间进行优化,确定了适合处理高有机质无烟煤的消解体系,评价了采用HG-AFS和ICP-MS测定其中总汞和总砷含量的可行性。结果表明,以硝酸-硫酸-氢氟酸(6∶4∶0.5)作为微波消解试剂,消解温度达205℃,保持30 min可将高有机质含量的无烟煤彻底分解,其中硫酸对无烟煤的消解起到了关键作用;ICP-MS与HG-AFS对汞的检测结果一致,回收率都达到98%以上,但由于砷的化学形态复杂,有机态砷不能全部转化无机态砷使得HG-AFS对砷的检测结果偏低。因此,对于有机质含量特别高(81%~90%)的煤炭样品,微波消解可将其彻底转化为溶液,用ICP-MS可以准确定量其中的汞和砷,而HG-AFS不能作为检测砷的有效手段。 相似文献
4.
增压微波消解-氢化物-原子荧光光谱法测定铁矿石中的砷 总被引：4，自引：0，他引：4
用微波消解方法处理样品,采用抗坏血酸-硫脲-磷酸作为掩蔽剂,以原子荧光光谱法实现了铁矿石中砷的测定。方法检出限0.35μg/L-1,加标回收率97.5%~106.5%。经标样分析验证,结果与标准值相符,测定的RSD为4.24%。采用该方法分离铁矿石中的砷,结果满意。 相似文献
5.
采用微波消解对样品进行前处理,建立了氢化物发生-双道原子荧光光谱同时测定化肥中砷和汞的方法。以20 g/L KBH4为还原剂,8%的盐酸为载液,测定砷和汞的负高压均为270 V,砷的灯电流为60 mA,汞的灯电流为20 mA。讨论了常见元素对测定的干扰,40 g/L的主量元素N、P、K,10倍于砷、汞浓度的杂质元素Te、Ca、Zn、Cu、Cr、Mn、Ni、Sb、Sn、Pb对砷和汞测定的影响满足分析要求。方法测定砷和汞的线性范围As为0.68～100μg/L,Hg为0.12～10μg/L;检出限As为0.68μg/L,Hg为0.12μg/L;方法精密度(RSD,n=5)低于8%。该方法具有前处理简便快速、易于操作、灵敏度高等特点,能满足化肥中砷和汞同时测定的要求。 相似文献
6.
氢化物发生-电感耦合等离子体发射光谱法同时测定土壤中痕量砷锑铋汞 总被引：4，自引：4，他引：0
土壤样品用水浴加热王水溶解1 h,在10%的盐酸介质下,用0.5 L/min的载气流量,10 g/L的硼氢化钠-氢氧化钠作为还原剂,将自行设计的一种新型氢化物发生器与电感耦合等离子体发射光谱法(ICP-AES)联用测定痕量砷、锑、铋、汞,一次溶样即可实现多元素在同母液同条件下同时测定。方法检出限为0.01～0.06 ng/g,加标回收率为92.0%～102.0%,精密度(RSD)低于5%。此方法通过加入抗坏血酸-硫脲溶液预先将砷和锑还原,汞的测定不受还原剂的影响,同时解决了目前多元素分次测量带来的不便和试剂消耗多等问题,样品前处理及测量过程快速、简单,无记忆效应的影响,适合环境样品中痕量砷、锑、铋、汞的同时测定。 相似文献
7.
8.
应用氢化物发生-原子荧光光谱法同时测定滑石中痕量砷和汞,并对样品的浸取方法及共存元素和实验奈件进行了研究。结果表明,用浓盐酸浸取样品,砷、汞溶出量最大;加入硫脲-抗坏血酸溶液后,滑石中共存元素铝、铁、钙、铜、铅、镉不干扰砷、汞的测定。方法的检出限为砷0.047 mg/L,汞3.9 ng/L;回收率为砷107.5%～109.2%,汞103.3%～130.0%;精密度(RSD,n=11)为砷0.6%,汞0.7%。建立的氢化物发生-原子荧光光谱同时测定滑石中砷、汞含量的分析方法能满足日常检验的要求。 相似文献
9.
索氏提取-原子荧光光谱法测定含油岩心中的汞和砷 总被引：1，自引：1，他引：0
原油对测定含油岩心中的汞和砷有很大影响,目前去除原油等有机物的方法主要有高温烧制、强酸高温氧化等,要求反应温度较高,会造成汞和砷的损失而使测定结果偏低。本文采用索氏提取法,以氯仿作为提取剂在75℃下低温提取分离岩心中的原油,再用50%的王水溶解剩余样品,原子荧光光谱法测定汞和砷的含量。该方法对汞和砷的检出限分别为0. 003mg/kg和0. 10mg/kg,相对标准偏差分别为7. 3%和5. 1%,加标回收率均大于92. 5%。与传统方法相比较,该方法避免了由于原油的疏水性造成样品与王水接触不充分、样品分解不完全和反应温度过高导致汞元素损失的问题,测定汞的相对标准偏差由33. 0%降低至7. 3%,测定砷的相对标准偏差由25. 0%提高至5. 1%,为含油岩心中其他元素的检测提供了借鉴。 相似文献
10.
改进了铁矿石样品溶解方法，尝试用硫-磷混酸溶解铁矿石样品，缩短了分析时间，提高了分析精度。溶解后的样品以银-二乙基二硫代氨基甲酸钠法（Ag—DDTC）用于部级标准物质测定，砷的测定结果与标准值相符；用于碱性矿石如球团样品中砷的分析，多名操作者的测定结果吻合。 相似文献
11.
酒石酸络合掩蔽锑-氢醌容量法测定锑矿石样品中的常量金 总被引：1，自引：1，他引：0
应用王水溶样-活性炭富集金-氢醌容量法测定高品位锑矿石的金量时,通常受到较高含量的锑硫砷汞等元素的干扰,硫砷汞碳及有机质可以通过阶梯升温焙烧去除,但是对锑则无明显去除作用。本研究在相关实验环节通过加入酒石酸使锑的干扰问题得到解决,包括:王水溶矿时加入酒石酸络合锑,防止锑的化合物在酸度或温度降低时水解,保证吸附金的活性炭灰化后的锑量小于0.3 mg;活性炭灰化除碳后,用王水溶解金时再加入酒石酸,消除了氢醌容量法滴定过程中少量锑的干扰。本方法只需在溶矿时加入一定量酒石酸,与氢溴酸除锑、盐酸等除锑方法相比具有原理简明、测试快速等特点,用于分析实际锑矿石的精密度(RSD)小于5%,加标回收率为92.0%~107.0%。 相似文献
12.
将试样置于潘菲氏管中加入还原铁粉，加热使汞与基体及共存元素分离，继而试验了汞蒸气-原子荧光光谱法测定汞的最佳条件,汞的检出限为0.05μg/L,线性范围为0.5～250μg/L，回收率为94.6%～102.5%。方法已应用于锌精矿中汞的测定,RSD（n=5）＜1%。 相似文献
13.
Chemical analysis for major and trace elements have been performed on 30 Swedish Precambrian iron ores and on some from Iran and Chile. The Swedish ores consist of apatite iron ores, quartz-banded iron ores, skarn and limestone iron ores from the two main ore districts of Sweden, the Bergslagen and the Norrbotten province. Some Swedish titaniferous iron ores were also included in the investigation. The trace element data show that the Swedish ores can be subdivided into two major groups: 1. orthomagmatic and exhalative, 2. sedimentary. Within group 1 the titaniferous iron ores are distinguished by their high Ti-contents. From the ferride contents of the Kiruna apatite iron ores, the ores are considered to be mobilization products of skarn iron ores from the Norbotten province. 相似文献
14.
Massive sulfide deposits in the Pacific and Ural provinces have varying mercury contents. The latter is lower in metamorphosed ores than in unmetamorphosed or in young ones. Two varieties of cenozoic sulfide ores are distinguished: 1) products of subcontinental solfataric action with high mercury content in pyrites, accompanied by cinnabar, 2) products of postvolcanic activity in submarine suites with low mercury content in sulfides (Kurokotype). A distribution of mercury between coexisting sulfides (in descending rank) corresponds to the sequence: sphalerite-chalcopyrite-pyrite. During metamorphism, sulfides loose their mercury (pyrite in higher degree than chalcopyrite). It is possible that mercury vaporised from sulfides has some influence on the formation of mercury ores at some distance from metamorphosed sulfide bodies within the same region. 相似文献
15.
Environmental mercury and arsenic sources in fossil hydrothermal systems, Northland, New Zealand 总被引：2，自引：0，他引：2
Northland, New Zealand has been affected by natural hot water spring systems depositing elevated concentrations of mercury
and arsenic over the past 5 million years. Due to the different erosion levels of these hot water systems, four principal
types of mercury and arsenic occurrences are found: active hot springs; layered surface deposits (sinters) deposited by hot
springs; highly fractured rock zones formed immediately beneath hot springs; and chemically altered and mineralized rock from
the deeper roots of hot spring systems. Mercury occurs principally as cinnabar and as a minor impurity (<1 wt%) in phosphate
minerals and iron sulfides, particularly marcasite. Mercury is irregularly distributed through limonitic cements formed during
oxidation. Arsenic occurs as a minor impurity (<1 wt%) in phosphate minerals and iron sulfides, particularly marcasite. Arsenic
is also variably dispersed through limonite, but not necessarily with mercury. Decomposition of marcasite constitutes the
most significant source of mercury and arsenic pollution from the studied sites. Release of mercury and arsenic into the environment
from marcasite, phosphates and limonite is enhanced by acidification of the sites (down to pH of 2), caused by oxidation of
iron sulfides. Mercury and arsenic concentrations of up to 100 parts per billion should be expected in waters near the deposits;
these concentrations are in excess of recommended drinking water levels.
Received: 9 April 1999 · Accepted: 2 August 1999 相似文献
16.
S. L. Wang C. Y. Lin X. Z. Cao X. Zhong 《International Journal of Environmental Science and Technology》2012,9(1):31-40
The Nansi Lake has been seriously affected by long-term intensive industrial and urban activities. The objectives of this study were to determine the content, distribution, and ecological risk of arsenic and investigate the geochemical relationships between arsenic forms and sediment mineral phases of the Nansi Lake. Twenty samples of surface sediments were collected and analyzed for arsenic contents and chemical forms. Results indicated that total content of arsenic in the sediment samples averaged 13.45?mg/kg and ranged from 8.27 to 21.75?mg/kg. The arsenic was mostly associated with iron oxides (67.3%), followed by the association with the residual fraction (19.2%). In addition, total content of arsenic was positively correlated with the organic matter and iron contents in the sediment. The molar ratios of iron oxide bound arsenic content to iron content are lower than the maximal molar ratios of arsenic to iron for natural hematite, magnetite, and goethite. The total content of arsenic in the sediment samples was usually higher than threshold effect concentration of 9.79?mg/kg, but lower than probable effect concentration of 33.0?mg/kg for arsenic in freshwater sediments. Adverse effects or toxicity to the aquatic organisms, caused by arsenic in the sediments of the Nansi Lake, will likely occur at these levels of arsenic contamination. 相似文献
17.
Although Mn is one of the major impurities in the economic iron ores from the Bahariya Oasis, information on its modes of occurrence and origin is lacking in previous studies. High-Mn iron ores from El Gedida and Ghorabi–Nasser iron mines were subjected to detailed mineralogical, geochemical, and petrographic investigations using X-ray diffraction (XRD), infrared absorption spectrometry (IR), Raman spectroscopy, X-ray fluorescence (XRF), scanning electron microscopy (SEM), and electron probe microanalyzer (EPMA) to clarify the modes of occurrence of Mn in these deposits and its origin. The results showed that the MnO2 contents range between 0.03 and 13.9 wt.%. Three mineralogical types have been identified for the Mn in the high-Mn iron ores, including: (1) inclusions within the hematite and goethite and/or Mn accumulated on their active surfaces, (2) coarse-grained and crystalline pyrolusite, and (3) fine-grained cement-like Mn oxide and hydroxide minerals (bixbyite, cryptomelane, aurorite, romanechite, manjiroite, and pyrochroite) between the Fe-bearing minerals. The Mn carbonate mineral (rhodochrosite) was detected only in the Ghorabi–Nasser high-Mn iron ores. Since IR patterns of low-Mn and high-Mn samples are almost the same, a combination of XRD analysis using non-filtered Fe-Kα radiations and Raman spectroscopy could be the best way to identify and distinguish between different Mn minerals.Assuming that both Fe and Mn were derived from the same source, the occurrence of high-Mn iron ores at the base of the stratigraphic section of the deposits overlain by the low-Mn iron ores indicated a supergene origin of the studied ores by descending solutions. The predominance of Mn oxide and hydroxide minerals in botryoidal shapes supports this interpretation. The small grain size of Mn-bearing minerals as well as the features of microbial fossils such as spherical, elliptical, and filamentous shapes of the Fe-bearing minerals suggested a microbial origin of studied iron ores.Variations in the distribution and mineralogy types of Mn in the iron ores of the Bahariya Oasis demanded detailed mineralogical and petrographic characterizations of the deposits before the beneficiation of high-Mn iron ores from the Bahariya Oasis as feedstock for the ironmaking industries in Egypt by magnetizing reduction. High Mn contents, especially in the Ghorabi–Nasser iron ore and occurrence of Mn as inclusions and/or accumulated on the surface of the Fe-bearing minerals would suggest a possible utilization of the high-Mn iron ores to produce ferromanganese alloys. 相似文献
18.
王小春 《大地构造与成矿学》1999,23(3):254-261
扼要介绍了川西炉霍裂谷微细浸染型金矿的地质特征, 通过地层和岩石中元素丰度特征,稀土元素、同位素、微量金的可化性实验等系统分析, 提出炉霍裂谷微细浸染型金矿的成矿物质来自三叠纪地层中的细碎屑质浊积岩建造和裂谷海底火山作用提供的深源物质。并讨论了矿质初始富集的机制。 相似文献
19.
铜镍硫化物矿床的成矿机理新探 总被引：7，自引：1，他引：6
描述岩浆中铜、镍、钴、铁迁移富集新机制。铜、镍、钴、铁呈氢化物迁移至地壳浅部,氢被氧化成水,铜、镍、钴、铁被硫化成硫化物及硫砷化物富集成矿床。 相似文献