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湿法磷酸中硫酸根含量的测定 总被引:1,自引:0,他引:1
据工业磷酸和食品级磷酸中的硫酸根含量可用目视比浊法的原理对湿法磷酸中的硫酸根含量进行了吸光光度比浊法的测定研究与分析。可得到目视比浊法不能得到的连续数据。与重量法相比无显著差异,反应后测定的不同地测定结果的影响不显著,RSD小于2%,回收率大于94%,可作湿法磷酸及其制品中硫酸根含量的一种快速,准确,简便的仪器分析方法。 相似文献
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采用带八级杆碰撞/反应池(ORS)的电感耦合等离子体质谱法(ICP-MS),直接测定丙烯腈或乙腈产品中的Fe、Cu,标准加入法定量.结果表明,方法的线性范围宽,线性相关系数均大于0.999.2种元素的相对标准偏差均低于5%,加标回收率在90%~110%.该方法简便、快速、准确. 相似文献
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ICP-AES测定钼铁中杂质元素 总被引:6,自引:0,他引:6
研究了用ICP-AES测定钼铁中硅、磷和铜的方法,建立了最佳工作条件,采用基体匹配方法,应用软件中谱线干扰校正程序消除了干扰,检出限小于0.005%,回收率在93%-108%之间,RSD小于1.0%。方法简便、快速、准确。 相似文献
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PSA分散固相萃取液相色谱柱后衍生荧光法测定蔬菜和水果中的13种氨基甲酸酯 总被引:4,自引:0,他引:4
建立了PSA分散固相萃取净化,液相色谱柱后衍生荧光法测定蔬菜和水果中13种氨基甲酸酯农药的分析方法。在建立的测定条件下,13种氨基甲酸酯的含量与峰面积之间成线性关系,相关系数大于0.994,保留时间的相对标准偏差在0.03%~0.22%之间,检测下限在2.00~2.28μg/kg范围内。西瓜、杏、茄子及胡萝卜中13种氨基甲酸酯的平均回收率在71.7%~110%之间,相对标准偏差在0.68%~15%之间,分析结果优于氨基柱固相萃取法。 相似文献
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Simultaneous determination of retinol, alpha-tocopherol and beta-carotene in serum by isocratic high-performance liquid chromatography. 总被引:3,自引:0,他引:3
A simultaneous determination of retinol, alpha-tocopherol and beta-carotene in serum by high-performance liquid chromatography is described. Total analysis time is 13 min. A reversed-phase (Ultrasphere ODS, 5 microns) column is used with a mobile phase of acetonitrile-methanol-dichloromethane (70:10:20, v/v/v) and a flow-rate of 1.2 ml/min. Retinol is monitored at 325 nm, alpha-tocopherol at 292 nm and beta-carotene at 450 nm. Serum is deproteinized with ethanol containing the internal standard (alpha-tocopherol acetate), then extracted with hexane. The evaporated organic layer is reconstituted with the mobile phase and injected. The choice of the eluent is discussed, as well as the choice of an internal standard and the need for an antioxidant during the extraction step. Sixteen different eluents are compared in terms of analysis time and selectivity. The linear concentration ranges (retinol 0.016-13.7 microM, alpha-tocopherol 0.18-91.8 microM, beta-carotene 0.05-5.75 microM), within-run coefficients of variation (retinol less than 7%; alpha-tocopherol less than 8%, beta-carotene less than 7%), between-run coefficients of variation (retinol less than 13%, alpha-tocopherol less than 9%, beta-carotene less than 8%) and recoveries (retinol greater than 95%, alpha-tocopherol greater than 91%, beta-carotene greater than 80%) are suitable for clinical investigations. Serum reference values were found to be 2.47 +/- 0.61 microM (retinol), 30.5 +/- 6.8 microM (alpha-tocopherol) and 0.91 +/- 0.55 microM (beta-carotene). A significant difference (p less than 0.001) between males and females was found for retinol. 相似文献
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火焰原子吸收法测定山楂叶中钙、锰、铁、锌、镁、铜、铅、铬的含量 总被引:4,自引:0,他引:4
对广西山楂叶进行湿法消化处理,利用火焰原子吸收分光光度法测定了其中微量元素的含量。结果表明,山楂叶中含有较丰富的Ca、Mg、Fe、Mn。该法的加标回收率为99.6%~105.0%,RSD≤0.71%,测定结果准确。 相似文献
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Carbon nanofiber (CNF) layers have been directly synthesized on nickel foils by chemical vapor deposition at 450°C using different H(2) concentrations and reaction times. The addition of 5% H(2) produces thicker, rougher and more porous CNF layers than when 1% H(2) is used. The roughness and porosity increases with reaction time when 5%, 10% or 20% H(2) are used; however, this effect is less pronounced when 1% H(2) is used. CNFs are 50-55 nm in diameter and have a fishbone type structure. We have studied the influence of CNF layer thickness, porosity and surface roughness on the interaction with water by measuring the contact angle. The water wetting properties of the samples are more significantly influenced by the CNF layer thickness than both surface roughness and porosity. When the CNF layer is thicker than ca. 20 μm, the surface is hydrophobic and the contact angle increases with surface roughness and porosity. When the CNF layer is thinner than ca. 20 μm, the surface is hydrophilic and the contact angle decreases with increasing surface roughness and porosity. This behavior is attributed to penetration of water, making contact with the hydrophilic C layer between the CNF layer and the foil. 相似文献