共查询到19条相似文献,搜索用时 66 毫秒
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采用高效液相色谱-氢化物发生原子荧光光谱联用测定了北京大气颗粒物中As(III),As(Ⅴ),二甲基砷酸(DMA)和一甲基砷酸(MMA)的含量。研究了仪器条件、流动相组成和梯度洗脱程序对砷形态分离的影响。实验结果显示,在优化的色谱与氢化原子荧光检测条件下,采用pH6.0,浓度为10 mmol/L和200 mmol/L NH4H2PO4为流动相A和B,在1~3 min内用60%的A和40%的B洗脱使砷的4种形态达到最佳分离效。As(III),As(Ⅴ),DMA和MMA的检出限为1.45,1.22,1.91和1.64 mg/L,回收率为90.5%~93.2%,相对标准偏差为0.38%~1.7%。方法适用于大气颗粒物中砷的形态分析研究。 相似文献
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大气颗粒物重金属环境地球化学研究进展 总被引:13,自引:0,他引:13
综述了国内外有关大气颗粒物重金属的研究进展,包括:对大气颗粒物重金属的来源、分布与积累、环境活性、迁移转化、生物毒性等方面的研究成果,并指出了该领域研究中的薄弱环节,展望了今后的研究发展趋势。 相似文献
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成都地区大气颗粒物中复杂有机物的色谱-质谱分析 总被引:11,自引:0,他引:11
〕本文报道了应用气相色谱和气相色谱-质谱联用法对成都地区大气颗粒物中复杂有机物的分析结果。实际分析中共鉴定出77种有机物,首次在成都地区大气颗粒物中发现含有烟碱这一新的污染物。同时对苯并[a]等28种主要污染物做了定量测定。结果表明,成都大气中的有机污染状况非常严重,急待采取有力措施加以改善。 相似文献
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大气颗粒物化学组成分析 总被引:8,自引:0,他引:8
大气颗粒物的化学组成非常复杂,其中包括大量矿质氧化物、可溶性硫酸盐、硝酸盐、海盐、多环芳烃、有机酸和有机氟等。大气颗粒物对局地、区域甚至全球大气辐射平衡、大气能见度、元素的生物化学循环具有重要影响,危害人体健康并参与大气非均相反应。化学组成是决定大气颗粒物各种环境效应的关键因素。国内外对大气颗粒物化学组成分析进行了大量的研究工作。特别是随着气动力学透镜的发展与应用,结合快速、灵敏的光谱和质谱检测手段,适合大气颗粒物化学组成的在线分析方法取得了较大的突破。 相似文献
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大气颗粒物中总碳含量的测量不确定度评定 总被引:1,自引:0,他引:1
分析了元素分析仪测定大气颗粒物中碳质组分的测量不确定度来源,对总碳含量的测量不确定度进行了评估。测定咖啡碱标准样品中的碳含量,称样量为1 500~2 500μg时,测定结果为(49.27±0.26)%;测定大气颗粒物样品中的总碳含量,样品面积为3.14 cm2时,测定结果为(106±3)μg/cm2。 相似文献
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A novel arsine generator glass assembly is constructed and reported for the spectrophotometric determination and speciation of arsenic in real samples. In an arsine generator, sodium borohydride is added dropwise to the acidic sample solution and arsine thus formed is reacted with silver diethyldithiocarbamate (Ag‐DDTC) ‐ Tritron‐X (TX‐100) solution in pyridine to form a red coloured complex. The complex showed the absorption maximum at λmax 540 nm. The molar absorptivity of the method was found to be (1.55) × 104 L mole?1 cm?1 at this wavelength. The presence of non‐ionic surfactant, i.e. TX‐100 in the Ag‐DDTC solution, makes the method ≈ 3 times more sensitive than the conventional Ag‐DDTC method. Beer's law is obeyed in the concentration range of 0.05–2.80 mg L?1 of arsenic. The detection limit of the method was calculated to be 20 μg L?1 As. Speciation of arsenite from other forms of arsenic in sample solutions was carried out by extraction of arsenite with Pb‐DDTC in chloroform, followed by spectrophotometric determination. After arsenite separation the sample is used for the arsenate determination. Total arsenic was determined by acid decomposition of the same sample. The speciation data were found to be comparable (±2%) with ICP‐MS, with better precision (< 1%). The method has been successfully applied for the speciation of arsenic in drinking water and dust samples of arsenic affecting the Rajnandgaon district of Chhattisgarh, India, and urine and blood samples of patients with arsenical diseases. Concentration of total arsenic in tube‐well water of this area was 3–6 times more than the permissible limit. Dust samples contained less amounts of arsenic than the ground water. 相似文献
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建立了稻米中4种砷元素形态的液相色谱-原子荧光光谱联用法(LC-AFS),样品用0.15mol/L的硝酸溶液微波提取50min,提取液经离心分离后,采用Hamilton PRP-X100色谱柱,45mmol/L KH2PO4-5mmol/L Na2HPO4缓冲液为流动相,砷形态4个组分能够在7min内达到基线分离,且无需调pH。优化了氢化物发生条件,使用了更低浓度的载流和还原剂。方法学实验结果表明,各组分在2~10ng/mL范围内线性关系良好,相关系数为0.9988~0.9998,各组分的检出限分别为0.29 ng/mL、0.47 ng/mL、0.62 ng/mL和1.16 ng/mL;各组分峰面积的相对标准偏差均低于3.11%;加标回收率为85.3%~112.8%;对稻米标准物质的分析测定结果表明该方法定值准确。最后,与GB 5009.11-2014中使用的提取及测量条件进行对比,表明该方具备法快速、环保、高效的特点。 相似文献
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液体硅肥中砷形态的氢化物发生原子荧光光谱分析 总被引:1,自引:0,他引:1
本文应用氢化物发生-原子荧光光谱法(HG-AFS)测定了液体硅肥中不同形态的砷含量。研究了酸介质、还原剂和增感剂对砷的荧光信号的影响。实验确定酸介质为2.5 mol.L-1HCl,还原剂和增感剂为5%硫脲 5%抗坏血酸混合溶液。在选定的实验条件下测得硅肥中三价砷、五价砷及总砷的含量分别为5.08 ng.L-1、0.72 ng.L-1、5.80 ng.L-1。三价砷和五价砷的检出限分别为72.0 ng.L-1和153 ng.L-1;方法的精密度为2.2%~4.1%,回收率为96.5%~104%。 相似文献
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鱿鱼丝中砷的形态分析 总被引:4,自引:0,他引:4
采用电感耦合等离子体-质谱(ICP-MS)测定了14种鱿鱼丝(Dried Shredded Squid,DSS)中的砷总量,发现14种鱿鱼丝中的砷总量均低于2μg.g-1;用高效液相色谱(HPLC)与ICP-MS联用技术建立了As(Ⅲ)、As(Ⅴ)、二甲基胂酸(DMA)、甲基胂酸(MMA)、砷甜菜碱(AsB)和砷胆碱(AsC)六种砷形态的分离分析方法;采用快速溶剂萃取(ASE)、超声溶剂提取(SON)和盐酸浸提三种不同的前处理方法分析了3种鱿鱼丝中的砷形态,发现鱿鱼丝中的砷主要以AsB形式存在。 相似文献
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A new speciation and preconcentration method based on dispersive liquid‐liquid microextraction has been developed for trace amounts of As(III) and As(V) in urine and water samples. At pH 4, As(III) is complexed with ammoniumpyrrolidine dithiocarbamate and extracted into 1‐Hexyl‐3‐methylimidazolium hexafluorophosphate, as an ionic liquid (IL) and As(III) is determined by electrothermal atomic absorption spectrometery (ETAAS). Arsenic(V) in the mixing solution containing As(III) and As(V) was reduced by using KI and ascorbic acid in HCl solution and then the procedure was applied to determination of total arsenic. Arsenic(V) was calculated as the difference between the total arsenic content and As(III) content. The effect of various parameters on the recovery of the arsenic ions has been studied. Under the optimum conditions, the enrichment factor 135 was obtained. The proposed method was successfully applied to the determination of trace amounts of As(III) and As(V) in water and biological samples. 相似文献
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Baoguo Sun Miroslav Macka Paul R. Haddad 《International journal of environmental analytical chemistry》2013,93(3):161-205
Abstract Capillary electrophoresis (CE) methods published over the period 1992–2000 for the speciation of tin, lead, mercury, selenium and arsenic are reviewed, with emphasis on the determination of the metallorganic species. Analytical conditions and detection techniques suitable for the determination of these species are discussed. The electrolytes covered by the review include both nonmicellar and micellar solutions. Although direct UV detection is still the predominant detection method for speciation by capillary electrophoresis, ICPMS has been gaining in significance because of its sensitivity and selectivity in elemental analysis. Further, ways of increasing the concentration sensitivity are outlined and discussed. Apart from the use of more sensitive detectors, this can be accomplished either by derivatisation of the analytes to form highly absorbing or fluorescent species or thorough leading a higher total amount of the analytes into the capillary. The latter aim can be achieved by preconcentration using solid-phase extraction (SPE), or using various on-capillary stacking methods. Finally, an overview of applications to speciation analysis is presented, organized according to the particular element being determined. 相似文献