共查询到18条相似文献,搜索用时 78 毫秒
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碘量法测定粘合剂RA的游离甲醛和结合甲醛 总被引:2,自引:0,他引:2
朱伟英 《中国石油和化工标准与质量》2003,(3):29-30,33
粘合剂RA适用于多种橡胶与多种骨架的粘合 ,采用碘量法对粘合剂的游离甲醛和结合甲醛进行测定 ,方法快速、灵敏、准确 相似文献
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测定样液中微量甲醛的含量时,需事先配制和标定含微量甲醛的标准溶液.碘量法是标定甲醛溶液的常用方法.为获得具有较好精确度的微量甲醛标准溶液,根据滴定分析原理进行计算后认为,配制质量浓度为1000 mg/L的标准甲醛储备液既适宜标定,也便于稀释应用.在标定中所用的硫代硫酸钠溶液和碘液配制成合适的浓度有利于提高标定甲醛储备液... 相似文献
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讨论了间接碘量法标定高锰酸钾(KMnO4)溶液准确浓度的原理和方法,采用了比理论值稍多量的KMnO4配制溶液。间接碘量法与Na2C2O4法相比,不仅操作简便,反应时间短,而且测定结果准确度高。 相似文献
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本文研究了用碘量法和非分散红外吸收法对二氧化硫浓度测定的对比.通过试验证明了.碘量法测得的二氧化硫的浓度均偏高.结果表明:非分散红外吸收法具有良好的准确度和精确度,适用于长时间测定二氧化硫混合气体浓度. 相似文献
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将甲醛标准贮备液的标定过程按照操作的先后顺序逐一分解,通过分析每一步测定结果的不确定度,并将其传递到下一步的不确定度分析中,最后得到甲醛标准贮备液浓度的不确定度. 相似文献
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电炉法生产黄磷的过程中,会产生大量的磷炉尾气,主要成分有CO及其它十多种杂质。为掌握其组分组成,以便有效净化及合理利用磷炉尾气,本公司内部开展了磷炉尾气组分的分析检测工作,通过分析和比较,对碘量法测定磷炉尾气中SO2的方法进行了探讨。 相似文献
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测定干菜中残留二氧化硫,为深圳瑞利来实业有限公司提供技术支持,以磷酸(1+3)为酸性环境蒸馏干菜,用0.05%碘淀粉吸收液吸收蒸馏出来的二氧化硫,边蒸馏边滴定,同时根据国家相关食品添加剂标准预先设计好相应的吸收液可以通过颜色变化直接判断残留物是否超标,反应速度快,重现性好,回收率高,最低检出限为1 mg/kg,可以用于公司质检部门快速测定含量以及判定是否残留物超标,具有操作简单、快速、对环境污染小、灵敏度高等优点,适用于食品中亚硫酸盐及二氧化硫残留量的测定。 相似文献
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电位滴定法在标定标准滴定溶液中的应用 总被引:1,自引:0,他引:1
探讨用自动电位滴定仪标定标准滴定溶液,并与国家标准中以指示剂判定滴定终点的方法进行了比对。结果表明,自动电位滴定法标定EDTA、硝酸银标准滴定溶液,滴定结果准确度高,数据重现性高于标准法,可满足化验室分析工作的需要。 相似文献
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Using a sonochemical reactor designed by the authors,the process of removing sulfur dioxide from cit- rate solution simulating the flue gas desulfurization was studied.The influence of ultrasonic frequency,ultrasonic power,reaction temperature,stirring speed,inert gases,initial concentration of sulfur dioxide and concentration of citrate on the efficiency of sulfur dioxide desorption,the stability of citrate solution and the concentration of sulfate radical was examined systematically.By comparing the desorption of sulfur dioxide with and without ultrasonifica- tion,it was concluded that(1)lower ultrasonic frequency results in a better degassing efficiency;(2)the use of ul- trasonification in desorbing sulfur dioxide from citrate solution improves the desorbing efficiency in some condi- tions,without changing the essence of chemical reactions;(3)sparging inert gas into the liquid can lower the vis- cosity of solution and the cavitating threshold,and raise the desorption efficiency.These results demonstrate a technical way for deep desorption of sulfur dioxide and provide the fundamental data for future industrial disposal of sulfur dioxide. 相似文献
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甲醛法测定铵盐中氮滴定终点的判断 总被引:1,自引:0,他引:1
甲醛法测定铵盐中的氮,由于在同一溶液中,实际使用了甲基红和酚酞两种指示剂,在以NaOH为标准溶液的滴定过程中,应注意溶液中的两种指示剂颜色的变化过程,当溶液呈现微橙红色并保持30s不褪色才为滴定终点。 相似文献
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Absorption of sulfur dioxide accompanied by reversible reaction in dimethylaniline has been studied using a short falling-film apparatus. Solutions of the amine in kerosene were used for this purpose. The effects of gas and liquid concentrations, contact time and temperature on the rate of absorption were investigated. Reaction equilibrium constant values were obtained at different temperatures from separate measurement of solubility of sulfur dioxide gas in kerosene as well as in dimethylaniline solutions. The heat of reaction was also calculated from these data. The absorption data could be satisfactorily interpreted by using the penetration theory of mass transfer with simultaneous pseudofirst order chemical reaction. The rate equations for the forward and reverse reactions were established. 相似文献
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二氧化氯是一种安全高效的消毒剂。采用国家行业标准中有效二氧化氯含量的测定方法的测量结果差异较大,用碘量法测定稳定态二氧化氯溶液中的有效二氧化氯含量时,活化反应的速度对测定有效二氧化氯的含量有一定影响。通过条件实验确定了碘量法测定有效二氧化氯含量的最佳测试条件,即:活化时间13min,盐酸稀释至与水体积比1:4,参考电压140V,可确保实验结果的平行性和再现性。 相似文献
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Na2S溶液吸收低浓度SO2的控制步骤分析 总被引:1,自引:0,他引:1
在一个半连续式反应器中采用硫化钠溶液吸收低浓度的SO2气体,随着SO2吸收量的增加,吸收液中pH值的变化出现两次突降,表现为三阶段模式.pH值第二次突降后的第三阶段吸收液失去完全吸收SO2的能力.SO2吸收的增强因子的变化范围为2.29+6.9×10-10C-H2i+1.1×10-2C-1H+i-(6.9×10-10C-2H+1.1×10-2C-1H+1)CSO2i/CSO21<φ<2.29+6.9×10-10C-2H+i+1.1×10-2C-1H+1,结合Gianni根据增强因子大小判断气体吸收的传质阻力控制步骤的分析,得出在本研究体系中,当吸收液pH>3.46时硫化钠溶液吸收低浓度的SO2气体的过程为气侧传质阻力控制.这一结论正好与实验相符. 相似文献
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A new method was developed to measure the vapor pressure of sulfur dioxide above various liquid absorbents. It was applied to pure 1-methyl-2-pyrrolidone and its aqueous solution at 50°C to 91°C for SO2 loadings of 3.73 × 10 4 kg/kg to 2.16 × 10 −2 kg/kg. A chemical model was developed. The heat of solution was calculated from the dependence of the vapor pressure on temperature and was 3.98 × 107 J/kmol (exothermic) for pure 1-methyl-2-pyrrolidone. The vapor pressures disagreed with the only previously published set of results but were confirmed by independent measurements with a gas chromatograph. 相似文献