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探讨了用CePO4共沉淀火焰原子吸收光谱法测定CoSO4溶液中的痕量Fe3 。共沉淀效率受pH、Ce(NO3)3和H3PO4用量的影响。试验结果表明,在溶液pH为3.0~4.0时,CePO4能够定量共沉淀CoSO4溶液中的Fe3 。对于20mL的样品溶液,方法的检出限为24.8μg/L,铁的加标回收率为101.7%。方法用于CoSO4试剂中Fe3 的测定,6份样品测定的RSD<5%。 相似文献
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Sébastien Aries Michel Valladon Mireille Polvé Bernard Dupré 《Geostandards and Geoanalytical Research》2000,24(1):19-31
Inductively coupled plasma-mass spectrometry has revolutionized the field of multi-elemental analysis because of its high sensitivity and speed of analysis. However, problems with polyatomic ion interferences during routine analysis can give rise to inaccuracies. We propose a method that systematically corrects for oxide and hydroxide interferences in routine analysis, for a wide range of materials. Oxide and hydroxide production for a specified element is calculated from measurements on each sample, as levels may depend on sample composition and may also vary with time. We show that oxide and hydroxide interferences can then be calculated for other elements, by reference to a set of oxide and hydroxide ratios measured on standard solutions. Validity of correction is controlled by internal tests involving two isotopes of one element with respect to experimental errors. The limits and validity of this approach are demonstrated with the analysis of selected reference materials. 相似文献
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Sequential Separation of Uranium,Hafnium and Neodymium from Natural Waters Concentrated by Iron Coprecipitation
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Carli A. Arendt Sarah M. Aciego Kenneth W.W. Sims Mark Robbins 《Geostandards and Geoanalytical Research》2015,39(3):293-303
A new ion exchange chromatography method is presented for the isolation of high field‐strength elements (HFSE) from freshwater and seawater samples that have undergone iron coprecipitation. Large volumes of water can be condensed through the application of iron coprecipitation, but clean separation of elements from the precipitate proves difficult. The technique described is a five‐column process designed to separate the HFSE, including rare earth elements such as neodymium and hafnium, before removing the iron and isolating uranium. Subsequent isolation of Nd and Hf was achieved using established ion exchange chromatography methods. The efficacy of our chemistry was verified by measurements of analytical reference materials – both reference solutions and seawater samples – subjected to the chemical separation methods described. Elution results indicate high yields (> 90%) determined by concentration measurements of a known reference material added to each column. Measurement results for isotopic compositions of seawater (U, Nd) and reference solutions (NIST SRM 960, U) were identical within uncertainty to previously published values. Compositions were identical between solutions (Spex CLMS3, Spex PLND2) that underwent different iron coprecipitation procedures. Isotopic determinations for reference materials JNdi‐1 and NIST SRM 960 measured with the mass spectrometers used in this study were in agreement with universally accepted values for these materials, and indicate high precision. 相似文献
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针对钻探工程施工中频繁发生的粘附卡钻事故,分析了发生粘卡事故的原因及相关因素,介绍了采用氢氧化钠水溶液作为解卡液的使用方法、措施和效果。 相似文献
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Gallium arsenide (GaAs) has both high saturated electron velocity and high electron mobility, making it useful as a semiconductor material in a variety of applications, including light‐emitting diodes (LEDs), integrated circuits (ICs), and microwave appliances. A side effect of the use of gallium (Ga) is the production of a relatively large amount of hazardous waste. This study aimed at the recovery of Ga and arsenic (As) from GaAs waste using hydrometallurgical methods involving leaching and coagulation and a dry annealing process that involves annealing, vacuum separation, and sublimation by heating. Our research has shown that GaAs can be leached using nitric acid (HNO3) to obtain 100% Ga and As with a leaching solution at pH 0.1, with subsequent adjustment of the leaching solution to pH 3 with sodium hydroxide (NaOH). Another method used a leaching solution at pH 2, then adjusting to pH 11 using NaOH. Ferric hydroxide (FeO(OH)) was added at 90°C after NaOH was added to the leaching solution. At pH 2 and 11, 55.5 and 21.9% of the As could be removed from the hazardous waste, respectively. The Ga could also be precipitated. When GaAs powder was heated to 1000°C over 3 h, 100% As removal was achieved, and 92.6% of the Ga was removed by formation of 99.9% gallium trioxide (Ga2O3). Arsenic was vaporized when the temperature was elevated to 1000°C, allowing arsenic trioxide (As2O3) to condense with 99.2% purity. The Ga2O3 powder produced was then dissolved and electrolyzed, allowing for 95.9% recovery of Ga with a purity of 99.9%. 相似文献
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根据八水氢氧化钡脱水制一水氢氧化钡的反应原理,采用真空加热脱水工艺,对八水氢氧化钡制备一水氢氧化钡工艺进行了研究。通过实验,找出了适宜的工艺条件。该工艺设备、操作简单,条件易于控制,尤其防止产品碳酸化更具有独特的优点。 相似文献
50.
Liang LU Yulin WANG Jing HE 《中国地球化学学报》2006,25(B08):255-255
Layered double hydroxides (LDHs) are a class of synthetic anionic clays whose structure can be described as containing brucite-like layers in which some of the divalent cations have been replaced by trivalent ions, giving rise to positively charged sheets. This charge is balanced by intercalation of anions in the hydrated interlayer regions. LDHs act as sorbents of anionic species through two types of reactions, namely, anion exchange and reconstruction, which further adds the possibility of recycling and reuse. The sorption of anions from aqueous solutions by structural reconstruction of a calcined LDHs is based on a very interesting property of these materials, the so-called memory effect: Calcination of LDHs produces intermediate non-stoichiometric oxides (CLDH) which undergo rehydration in aqueous medium and give back the hydroxide structure with different anions in the interlayers. Perchlorate's (ClO4^-) strong oxidizing capabilities make it ideally suited for use as a propellant in solid rocket fuel. However, this use in rocket fuel has led to the ClO4^- contamination of considerable amounts of water throughout the United States. ClO4^- has been shown to inhibit iodide uptake by the thyroid gland; and in large doses, it has been linked to anemia and fetal brain damage. This is especially a problem in China. With the recent emergence of perchlorate contamination as an important drinking water quality issue, adsorption by calcined LDHs was studied for ClO4^- removal. In this work, the effect of various factors such as (a) CLDH structure, (b) conditions for removal of ClO4^- ion, such as dosage of adsorbent, initial concentration of ClO4^-, and temperature and (c) co-existing anions in perchlorate contamination on the removal of ClO4^-, have been investigated, respectively. 相似文献