共查询到19条相似文献,搜索用时 125 毫秒
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根据铜锍的组成结构特点,建立了一种测定铜锍中铜含量的方法,重点讨论了混合酸对铜锍进行溶解的前处理及样品滴定过程。方法铜的测定范围:4.80%~32.00%,回收率:97.70%~101.26%,精密度即标准偏差:0.026 %~0.10%。该方法能够较好地解决铜锍中铜含量测定难的问题。 相似文献
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试验研究了铜冶炼烟尘中铜含量的测定方法,试料用盐酸、氢氟酸、硝酸、高氯酸及硫酸分解,氢溴酸除去砷、锡、锑,硫酸除去硒的干扰。进一步对滴定条件和共存元素的干扰及消除进行了试验,最终确定了最佳条件。按照实验方法测定6个铜冶炼烟尘样品中铜量,结果的相对标准偏差为0.22%~0.65%,精密度高,准确度好。样品加标回收率在98.92%~100.38%之间, 适用于铜冶炼烟尘中铜含量为5.00 %~65.00 %的测定。 相似文献
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根据铜锍的组成结构特点,建立了一种测定铜锍中铜含量的方法,重点讨论了混合酸对铜锍进行溶解的前处理及样品滴定过程。在4.80%~32.00%铜的测定范围内,加标回收率为97.70%~101.26%,相对标准偏差为0.24%~0.53%。方法能够较好地解决铜锍中铜含量测定难的问题。 相似文献
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《中国无机分析化学》2019,(5)
研究了铜冶炼烟尘中铜含量的测定方法,试料用盐酸、氢氟酸、硝酸、高氯酸及硫酸分解,氢溴酸除去砷、锡、锑,硫酸除去硒的干扰。进一步对滴定条件和共存元素的干扰及消除进行了实验,最终确定了最佳条件。按照实验方法测定6个铜冶炼烟尘样品中铜含量,结果的相对标准偏差为0.22%~0.65%,精密度高,准确度好。样品加标回收率在98.9%~100%,适用于铜冶炼烟尘中铜含量为5.00%~65.00%的样品测定。 相似文献
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根据氯离子在铂电极上的电化学氧化特性,用DZ-1B型电镀添加剂测定仪测定镍、铬、铁和铜镀液中氯离子的浓度。操作简便.快速,适用于电镀车间的镀液分析。 相似文献
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李庆在 《理化检验(化学分册)》1994,30(6):334-334
在粗铜电解精炼过程中,铜电解液中铜的测定常用碘量法,由于As(Ⅱ)等杂质的干扰,须经过掩蔽和氧化等预处理,操作时间较长,且结果稳定性较差.差示光度法具有测定高含量的优点,本文利用在硫酸介质中铜离子的本色,寻求差示光度法测定铜的各种条件,拟定了铜电解液中铜的快速测定法.本法操作简便,稳定性好,结果与碘量法相吻合. 相似文献
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建立快速溶剂萃取-高效液相色谱法测定枸杞子中四螨嗪残留量的方法.枸杞子样品经快速溶剂萃取,硅胶层析柱净化.分析时用C18柱(4.6 mm×250 mm,5 μm)分离,V(甲醇):V(水)=70:30为流动相,流速1.0 mL/min,检测波长277nm,参比波长324nm.该方法的线性关系良好(r=0.9999),最低检出限为0.005 mg/kg,加标回收率在81.2%~96.9%范围内,相对标准偏差小于7.7%.该方法快速、准确、简便,能够满足检测要求. 相似文献
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Recently a new mechanism for copper deposition has been proposed by Gabrielli et al. [C. Gabrielli, P. Moçotéguy, H. Perrot, R. Wiart, J. Electroanal. Chem. 572 (2004) 367]. In this mechanism cupric ions are supposed to be reduced by two different paths. The first path is a direct discharge of cupric ions in two steps, and the second follows a parallel path through a catalytic complexation with chloride ions and adsorption of copper (I) chloride onto the copper surface. In the second path, chloride ions are consumed in the first step and produced in the second step, therefore chloride ions act as catalysts. The rates of the two steps of the second path are equal under steady-state condition and the concentration of Cl− anion is constant in the electrolytic solution. In contrast the step rates are not equal under dynamic conditions causing a concentration impedance of chloride ions with a rather unusual expression. Such an impedance is calculated and thoroughly examined in this paper. Finally, decomposition of the Faradaic impedance into the sum of concentration impedances of adsorbed species and chloride ions makes it possible to determine the contribution of each concentration impedance to the global impedance of the electrode. 相似文献
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A rapid, sensitive and selective high performance liquid chromatography (HPLC) method was developed and validated for determination of loganin in rat tissues. Samples were prepared based on a simple protein precipitation. Separation of loganin was achieved on a reversed-phase C(18) column (250 x 4.6 mm, 5 microm) with a mobile phase consisting of acetonitrile and water (16:84, v/v) at a flow rate of 1.0 mL/min. The detection wavelength was set at 236 nm and the temperature of the column was kept at 30 degrees C. The method was applied to study tissue distribution of loganin in rats after a single administration of loganin at a dose of 20 mg/kg. The highest level was observed in kidney, then in stomach, lung and small intestine. The lowest level was found in brain. The peak levels were attained at 90 min in most tissues. It was indicated that kidney was the major distribution tissue of loganin in rats, and that loganin had difficulty in crossing the blood-brain barrier. It was also found there was no long-term accumulation of loganin in rat tissues. 相似文献
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An anodic stripping voltammetric method was developed in order to determine copper in the water used to prepare haemodialysis solutions. The interference from organic matter was overcome by high-pressure bomb mineralization. The electrochemical results were compared with those obtained by using graphite furnace atomic absorption spectrometry and the correlation was excellent (r = 0.983, p < 0.001). The detection limit was 0.2 μg l?1 copper. 相似文献
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Dos Santos WN da Silva EG Fernandes MS Araujo RG Costa AC Vale MG Ferreira SL 《Analytical and bioanalytical chemistry》2005,382(4):1099-1102
Chocolate is a complex sample with a high content of organic compounds and its analysis generally involves digestion procedures that might include the risk of losses and/or contamination. The determination of copper in chocolate is important because copper compounds are extensively used as fungicides in the farming of cocoa. In this paper, a slurry-sampling flame atomic-absorption spectrometric method is proposed for determination of copper in powdered chocolate samples. Optimization was carried out using univariate methodology involving the variables nature and concentration of the acid solution for slurry preparation, sonication time, and sample mass. The recommended conditions include a sample mass of 0.2 g, 2.0 mol L–1 hydrochloric acid solution, and a sonication time of 15 min. The calibration curve was prepared using aqueous copper standards in 2.0 mol L–1 hydrochloric acid. This method allowed determination of copper in chocolate with a detection limit of 0.4 g g–1 and precision, expressed as relative standard deviation (RSD), of 2.5% (n=10) for a copper content of approximately 30 g g–1, using a chocolate mass of 0.2 g. The accuracy was confirmed by analyzing the certified reference materials NIST SRM 1568a rice flour and NIES CRM 10-b rice flour. The proposed method was used for determination of copper in three powdered chocolate samples, the copper content of which varied between 26.6 and 31.5 g g–1. The results showed no significant differences with those obtained after complete digestion, using a t-test for comparison. 相似文献
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在非离子型微乳液(OP/n-C5H11OH/n-C7H16/H2O)存在下,Cu2+与硫氰酸盐形成络阴离子[Cu(SCN)4]2-,在pH 3.6乙酸盐缓冲溶液中,该络阴离子再与乙基紫(EV)形成吸附型离子络合物,该络合物的组成为[Cu(SCN)4]2-:EV=1:2,最大吸收波长为660nm,表观摩尔吸光系数ε660为1.08×l05L.mol-1.cm-1,Cu2+含量在1.7~18.0μg/50 mL范围内符合比尔定律,检出限为0.5μg/50 mL,用该方法测定了钢中的铜,相对标准偏差小于2%。 相似文献