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建立液相色谱原子荧光联用仪(LC-AFS)测定饲料中的无机砷的方法。采用微波提取样品中的无机砷,LC-AFS测定样品中的无机砷。结果表明,无机As(Ⅲ)和无机As(Ⅴ)在标准曲线范围内线性关系良好,相关系数均大于0.999,检出限As(Ⅲ)为0.020 mg/kg,As(Ⅴ)为0.040 mg/kg。6次重复性试验的相对标准偏差分别为4.28%、8.62%。对样品进行了3个不同浓度水平下的加标回收率试验,平均加标回收率在92.3%~116%之间。方法简单快速,结果准确,适用于饲料中无机砷的测定。 相似文献
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土壤中砷及砷化合物含量的测试—高效液相色谱-电感耦合等离子体质谱联用法 总被引:1,自引:0,他引:1
砷是一种有毒并致癌的化学元素,砷污染已经是全球十分严重的环境与健康问题。砷的化合物分为无机砷和有机砷两种,不同形态砷的毒性差异较大,所以准确测定土壤中各种砷的形态和价态具有重要的意义。文章主要介绍了土壤中的无机砷和砷化合物经过提取,通过HPLC分离后,用ICP-MS进行测试。本方法的检出限为:砷甜菜碱+砷胆碱(AsB+AsC)160 mg/kg,亚砷酸盐(As(III)80 mg/kg,二甲基砷酸(DMA)80mg/kg,一甲基砷酸(MMA)80 mg/kg,砷酸盐(As(V)80 mg/kg。 相似文献
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《Chemical engineering journal (Lausanne, Switzerland : 1996)》2001,81(1-3):187-195
Steady state experiments were conducted on arsenic sorption from aqueous solutions by natural solids to test the feasibility of these materials to act as concentrator for arsenic removal from groundwater and drinking water. The solids considered were natural zeolites, volcanic stone, and the cactaceous powder CACMM. The arsenic species studied were As(III), As(V), dimethylarsinic acid (DMA) and phenylarsonic acid (PHA). The arsenic removed was determined from the data obtained by measuring the concentration diminution of the arsenic species in the liquid phase at equilibrium before and after the adsorption experiment by means of ICP-AES for the total concentration of arsenic and IC-ICP-MS to determine the arsenic species. The latter method allowed the detection of As(V) additionally formed as a result of the oxidation of As(III) on some of the zeolites. The sorption of the arsenic species onto zeolites was studied on both non-activated and activated zeolites, as well as on zeolites hydrogenated or modified with iron, and with respect to varying pH. The kinetics and the ability to desorb and readsorb the arsenic species were investigated for selected zeolites. 相似文献
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《分离科学与技术》2012,47(15):2380-2390
A laboratory study was conducted to investigate the ability of ferric ion loaded red mud (FRM) for the removal of arsenic species from water. The adsorbent material was characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. For an initial arsenic concentration lower than 0.3 mg/L, the FRM with a dosage of 1 g/L was able to reduce As(III) at pH 7 below 10 µg/L, the maximum contaminant level (MCL) of arsenic in drinking water set by the World Health Organization. In the case of As(V) removal, FRM was also particularly effective in reducing the initial arsenic concentration value of 1 mg/L at pH 2, below the MCL requirement of arsenic for drinking water. According to kinetic sorption data, the initial stage of adsorptions of As(III) and As(V) onto FRM were mainly governed by the external diffusion mechanism; however, upon saturation of the external adsorbent surface, the arsenic species were eventually adsorbed by intraparticle diffusion mechanism. The present results are promising for using the very inexpensive FRM as a low-cost material that is effective in remediating drinking waters contaminated with low concentrations of arsenic species. We report here the sorption kinetics and adsorption mechanisms of As(III) and As(V) on the FRM that has not been decsribed previously. 相似文献
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The forthcoming introduction of lower standards for arsenic in drinking water requires new technologies for arsenic removal. We report the development of an electrochemical unit for remediating domestic water supplies for homes without municipally treated water. Electrolysis in a two‐anode system provides oxidants to convert As(III) to As(V) in situ, and a sacrificial anode to deliver iron into solution. Conditioning tanks after each electrolysis step ensure completion of the chemical reactions. At the pH of domestic water, As(V) co‐precipitates with Fe(OH)3; subsequent filtration leaves <10 ppb of inorganic arsenic in solution. 相似文献
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快速吸附去除废水中无机砷的技术,由于其高效性成为污水处理领域亟需的一种技术。采用草酸沉淀法制备了不同铁锰比(物质的量比)的铁锰复合草酸盐,以铁锰复合草酸盐为前驱体通过热分解得到铁锰元素均匀分布的复合氧化物,以铁锰复合氧化物为吸附剂吸附去除废水中的无机砷。在超声波辅助下,铁锰复合氧化物对废水中无机砷的去除效果显著。实验结果表明,铁锰物质的量比为6:4的铁锰复合氧化物,因具有较高的比表面积(396.6 m2/g)和独特的形貌,超声辅助1 min对废水中无机砷的吸附率可达95%以上。吸附动力学研究表明,该吸附过程符合准二级动力学模型,吸附速率常数为1.11 g/(mg·s)。吸附剂再生实验表明,将吸附砷的吸附剂采用碳酸氢钠溶液洗脱重复用于吸附实验,吸附剂重复使用3次对砷的吸附率仍可达到83.6%。 相似文献
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在酸性条件下,用硫化钠作还原剂和沉淀剂,还原-沉淀脱除普通工业品羟基亚乙基二膦酸(HEDPA)中的杂质砷。系统考察了硫化钠加入量、溶液pH、反应温度、反应时间、搅拌速度等因素对脱砷效果的影响,其适宜反应工艺条件为:n(硫化钠)∶n(砷)=4∶1,pH=0.5,反应温度50℃,反应时间2h,搅拌速度90r/min。在该工艺条件下脱砷率达99.3%,可制得高品质低含量砷羟基亚乙基二膦酸(HEDPA),其砷的质量浓度为0.28mg/L,可广泛用作日用化学品添加剂和药物合成的原料。 相似文献
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P. Mondal B. Mohanty C. B. Majumder N. Bhandari 《American Institute of Chemical Engineers》2009,55(7):1860-1871
A study on kinetics and equilibrium is presented on the adsorption of arsenic species from simulated groundwater containing arsenic (As(III):As(V)::1:1), Fe and Mn in concentrations of 0.188 mg/L, 2.8 mg/L and 0.6 mg/L, respectively, by iron impregnated granular activated charcoal (GAC‐Fe). Also presented is the interaction effect of As, Fe and Mn on the removal of arsenic species from water, which simulates contaminated groundwater. Among conventional models, pseudo second‐order kinetic model and Freundlich isotherm were adequate to explain the kinetics and equilibrium of adsorption process, respectively. However, in comparison to conventional isotherm empirical polynomial isotherm provided a more accurate prediction on equilibrium specific uptakes of arsenic species. Effects of initial concentrations of As, Fe and Mn on the removal of total arsenic (As(T)), As(V) & As(III) have been correlated within the error limit of ?0.2 to +5.64%. © 2009 American Institute of Chemical Engineers AIChE J, 2009 相似文献
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Ping Na Xiumin Jia Bin Yuan Yuan Li Jiyu Na Yuchen Chen Linshuang Wang 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2010,85(5):708-714
BACKGROUND: Arsenic pollution in drinking water has been found in most countries. Arsenate (As(V)) and arsenite (As(III)) are two major forms of inorganic arsenic species, and the latter is the more toxic. The removal of arsenic ions from water has attracted increased attention, and therefore further understanding and development of techniques for removal of arsenic ions are required. RESULTS: Adsorption of arsenate and arsenite from aqueous solutions using Ti‐pillared montmorillonite (Ti‐MMT) was investigated as a function of contact time, pH, temperature, coexisting ions, and ionic strength. The adsorption of both arsenate and arsenite were temperature and pH dependent, indicating different adsorption mechanisms. The effect of coexisting ions on the adsorption was also studied and, among the ions investigated, only phosphate had a noticeable influence on the adsorption of arsenate, while the effect of other ions was negligible. A pseudo‐second‐order chemical reaction model was obtained for both arsenate and arsenite; adsorption isotherms of arsenate and arsenite fitted the Langmuir and Freundlich isotherm models well. X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS) were used to study the nature of surface elements before and after adsorption. CONCLUSIONS: This work demonstrates that Ti‐pillared montmorillonite is an efficient material for the removal of arsenate and arsenite from aqueous solutions. Experimental parameters such as contact time, solution pH, temperature, initial concentration, coexisting ions, and ionic strength have been optimized. Copyright © 2010 Society of Chemical Industry 相似文献
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Agusa T Fujihara J Takeshita H Iwata H 《International journal of molecular sciences》2011,12(4):2351-2382
Individual variations in inorganic arsenic metabolism may influence the toxic effects. Arsenic (+3 oxidation state) methyltransferase (AS3MT) that can catalyze the transfer of a methyl group from S-adenosyl-l-methionine (AdoMet) to trivalent arsenical, may play a role in arsenic metabolism in humans. Since the genetic polymorphisms of AS3MT gene may be associated with the susceptibility to inorganic arsenic toxicity, relationships of several single nucleotide polymorphisms (SNPs) in AS3MT with inorganic arsenic metabolism have been investigated. Here, we summarize our recent findings and other previous studies on the inorganic arsenic metabolism and AS3MT genetic polymorphisms in humans. Results of genotype dependent differences in arsenic metabolism for most of SNPs in AS3MT were Inconsistent throughout the studies. Nevertheless, two SNPs, AS3MT 12390 (rs3740393) and 14458 (rs11191439) were consistently related to arsenic methylation regardless of the populations examined for the analysis. Thus, these SNPs may be useful indicators to predict the arsenic metabolism via methylation pathways. 相似文献
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This article deals with the experimental investigation related to the removal of arsenic from a simulated contaminated groundwater by the adsorption onto Cu2+ impregnated granular activated carbon (GAC‐Cu) in presence of impurities like Fe and Mn. The effects of adsorbent concentration, pH, and temperature on the percentage removal of total arsenic (As(T)), As(III), and As(V) have been discussed. Under the experimental conditions, the optimum adsorbent concentration for GAC‐Cu has been found to be 6 g/L with an agitation time of 24 h, which reduces the As(T) concentration from 188 to 8.5 µg/L. Maximum removal of As(V) and As(III) has been observed in the pH range of 7–9 and 9–11, respectively. Removal of all the above said arsenic species decreases slightly with increase in temperature. Presence of Fe and Mn increases the adsorption of arsenic species. Under the experimental conditions, at 30°C, maximum % removals of As(T), As(III), As(V), Fe, and Mn are found to be 95.5%, 93%, 98%, 100%, and 40%, respectively. It has also been observed that maximum regeneration (~94%) of spent GAC‐Cu is exhibited by a 5NH2SO4 solution. 相似文献