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建立了重铬酸钾褪色光度法测定异烟肼含量的方法,探讨了重铬酸钾褪色光度法测定异烟肼的最佳条件。在硫酸介质中,重铬酸钾能氧化异烟肼,其吸光度随异烟肼质量浓度的增加而减小,且吸光度减小值与异烟肼的质量浓度服从比尔定律,因此通过测定吸光度减小值可间接测定异烟肼的质量。在0.008 020~0.048 12mg/mL范围内异烟肼质量浓度与吸光度减小值呈良好的线性关系,线性回归方程为ΔA=0.011 2+1.506 9c(mg/mL),线性相关系数(r)=0.999 7。应用于异烟肼片中异烟肼的质量测定,结果与药典法一致。 相似文献
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在稀硫酸溶液中,甲醛对KClO3氧化罗丹明B褪色反应有催化作用,研究了其动力学条件,建立了测定痕量甲醛的动力学光度分析法,线性范围为0.45~4.55μg/mL,检出限为1.5×10-3g/mL,相关系数,r为0.9995. 相似文献
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《广东化工》2017,(21)
在硫酸介质中,溴酸钾能氧化酸性铬深绿G褪色使其吸光度下降,而苯胺的加入能明显地催化这一反应,其催化程度与加入苯胺的浓度有关,据此建立了酸性铬深绿G褪色催化动力学光度法测定痕量苯胺的新方法。考察了不同试验条件对催化反应灵敏度的影响,得到了最佳试验条件:硫酸2.0 mL,溴酸钾2.8 mL,酸性铬深绿G 1.0 mL,反应温度55℃,加热反应时间5 min。校准曲线的线性范围为20~120μg/L,线性回归方程为ΔA=0.0098+0.21C,相关系数R=0.9923。方法检出限为1.5×10~(-6) g/L。实验方法用于测定印染废水中苯胺,结果的相对标准偏差(RSD)分别为2.6%和2.1%;回收率分别为108.5%和105.3%。 相似文献
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基于在0.5 mol/L的硫酸介质中,痕量锡对溴酸钾氧化邻苯二酚紫的褪色反应具有催化作用,建立了催化光度法测定痕量锡的动力学光度法。讨论了酸度,氧化剂,显色剂,反应时间,反应温度,干扰离子等因素的影响,确定了该体系反应的最佳条件为:0.5 mol/L硫酸1.5 mL;0.1 mol/L溴酸钾1.25 mL;2.0×10-4mol/L邻苯二酚紫3.5 mL;反应时间为7 min;反应温度为100℃。在最佳的条件下,方法的检出限为4.51×10-3g/mL,线性范围为0~3μg/25 mL。进行了平行测定(n=11),其相对标准偏差1.88%,该方法简便,设备简单,易于操作,并且具有较高的灵敏度和选择性。用于水样、人发中痕量锡的测定,相对标准偏差分别为0.312%和1.11%,标准加入回收率分别为99.8%和99.5%。 相似文献
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Fe~(2+)-H_2O_2在酸性介质中氧化孔雀石绿反应褪色,但丙二醛加入Fe~(2+)-H_2O_2-孔雀石绿组成体系抑制褪色反应,且体系的吸光值随着丙二醛的含量增加呈线性增长。据此原理建立可见光分光光度法测定溶液中丙二醛的含量。在最优实验条件下,波长λ=620 nm,175μL硫酸、40μL硫酸亚铁、400μL孔雀石绿,140μL过氧化氢,反应时间为15 min、反应温度35℃时,线性回归方程为:ΔA620 nm=0.197 1ρ-0.014 3(ρ:μg/mL),线性范围为0.125~3.50μg/mL,检出限(3S/K)为0.068μg/mL,该方法分析挂面中的丙二醛的含量,回收率在95.7%~107.1%之间,分析方法可行。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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The miscibility of various amorphous polybutadienes with mixed microstructures of 1,4 addition units (cis, 1,4 and trans 1,4) and 1,2 addition units have been investigated. The studies here involved optical transparency, differential scanning calorimetry, and small angle light scattering. It was found that a 90 percent (cis) 1, 4 addition polybutadiene was immiscible with high (91 percent) 1,2 addition polybutadiene. Reduction of the 1,2 content to 71 percent induced an upper critical solution temperature (UCST) with the cis 1,4 polymer. Polybutadienes with 50 percent and 10 percent 1,2 contents were miscible above the crystalline melting temperature of the cis 1,4 polybutadiene. Immiscibility of the 91 percent 1,2 addition polymer was also found with a 10 percent 1,2 polybutadiene. The latter polymer also exhibits an UCST with the 71 percent 1,2 polymer. The results are used to interpret the characteristics of blends of polybutadienes of varying microstructure. 相似文献
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以F类粉煤灰为例,详细介绍了测定粉煤灰中烧失量的步骤、计算数学模型、影响测量不确定度的因素以及各项测量不确定度分量评定,人员、设备、材料、方法、环境都是影响测量不确定的因素。 相似文献
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我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
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