共查询到20条相似文献,搜索用时 171 毫秒
1.
2.
本文介绍了测定烷基二苯醚磺酸盐产品中活性物含量的方法、原理及步骤,并对直接两相滴定法与电位滴定法两种方法进行了比较。结果表明:电位滴定法具有应用广泛、操作方便、精密度高、重现性好等特点,可用于烷基二苯醚磺酸盐活性物含量的测定。 相似文献
3.
4.
5.
研究了采用自动电位滴定仪测定己内酰胺中的过氧化物含量,确定了仪器操作的最佳条件,并与化学滴定法进行比较。结果表明:仪器的最佳操作条件为电位差0.5 mV,滴定剂最小添加量0.002 mL,滴定剂最大添加量0.05 mL,阈值25 mV/mL,在此条件下测定己内酰胺中的过氧化物含量,其加标回收率为91.74%~107.14%,相对标准偏差为2.95%~4.60%;与化学滴定法相比,其电位滴定法的精密度较高,且试样的颜色对测定没有影响。 相似文献
6.
本文采用玻璃电极为指示电极,甘汞电极为参比电极的电位滴定法测定邻氨基对甲酚含量。本方法简便、准确,同时还将电位滴定法与重氮法测定邻氨基对甲酚的结果进行了比较。 相似文献
7.
用摩尔法和电位滴定法测定季铵盐含量,发现两种方法之间存在一个基本恒定的方法误差,摩尔法比电位滴定法的测定结果平均偏高3.90%,将此作为校正数值进行校正,其结果摩尔法与电位滴定基本一致,因此可用简便的摩尔法代替复杂费时的电位滴定法进行季铵盐含量的测定。 相似文献
8.
9.
10.
通过对ISO 8985:1998(E)水解反滴定法测定乙烯/乙酸乙烯酯(EVA)中乙酸乙烯酯(VA)含量(质量分数)的研究,发现该方法存在指示剂颜色不易判断、分析数据平行性差等问题。拟采用电位滴定法取代ISO8985:1998(E)回流反滴定法中颜色指示剂法测定EVA中VA含量,利用电位突跃点判断滴定终点,并对该方法的测定条件进行优化。结果表明,电位滴定法克服了指示剂不能准确判断滴定终点的问题,与颜色指示剂法相比,电位滴定法具有精密度高,操作简便、快捷等优点。 相似文献
11.
12.
13.
14.
The molecular weight (MW) of chitosan (CS) was determined by viscometric method (using Mark‐Houwink equation) as well as by gel permeation chromatography, and the degree of deacetylation (DDA) of CS was measured by potentiometric titration method and Gran‐type linearization method. The values of DDA were obtained ~ 83% (by potentiometric titration method) and ~ 86% (by Gran‐type linearization method). The self‐assembled nanoparticles of CS/plasmid DNA (pDNA) complex were prepared by varying the concentration of CS. The formation of CS/pDNA complex was confirmed by 0.8% agarose gel electrophoresis and the particle size of the self‐assembled nanoparticle was determined by dynamic light scattering, atomic force microscopy and scanning electron microscopy. The stability of CS/pDNA complexes was determined by turbidity test with the help of UV‐Vis spectroscopy. The effect of ionic strength on the complexes was also observed by means of fluorescence spectroscopy. The cytotoxicity of CS on the HeLa cell line was observed by absorbance of MTT (3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay and showed that CS has lower cytotoxicity in HeLa cells compared with that of poly (L ‐lysine) in 293T cells. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
15.
研究了用高氯酸标准溶液对对氨基苯甲酸正丁酯含量的非水滴定,具体方法为:精确称量对氨基苯甲酸正丁酯,用约25 mL的冰醋酸微热溶解。用配制好的高氯酸进行电位滴定,应用一阶导数法得出滴定结果。此方法容易操作,回收率在98.5%~103.9%之间。 相似文献
16.
电位滴定法测定柠檬酸钠含量 总被引:1,自引:0,他引:1
采用电位滴定法测定柠檬酸钠的含量,以高氯酸溶液非水滴定柠檬酸钠测定电位差,用二级微商法处理来确定反应终点,从而提高柠檬酸钠含量测定的精密度。 相似文献
17.
The protonation constant of the NH2 function was determined by the method of Katchalsky and Spitnik and by the SUPERQUAD fitting procedure. Samples with higher concentrations of chitosan indicated aggregations of polymer chains, which led to a loss in the effective concentration of the ligand (L). It followed, as a result of potentiometric titrations, that an excess of L of microcrystalline chitosan (MCCh) with a deacetylation degree of 0.90 was a complexing agent toward the metal (M), which was Ni(II) or Mn(II). Species ML and ML2 were accepted by SUPERQUAD for both of the M's, where coordination occurred via the amino nitrogen. For Ni(II), however, the hydroxyl oxygen may also have been an electron‐pair donor at lower excesses of MCCh and, by that, made possible the formation of five‐membered chelate rings in the hydroxyl deprotonated MLH‐1 species. The evaluated formation constants were compared with the values known until now for monomeric D ‐glucosamine. Additional confirmation of the M–L interaction was determined by the spectrophotometric titration of a Ni(II)–MCCh solution. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2572–2577, 2005 相似文献
18.
双突跃电位滴定法测定壳聚糖脱乙酰度 总被引:19,自引:0,他引:19
用 Microsoft Excel研究了电位滴定法测定壳聚糖的脱乙酰度的滴定曲线 ,利用两个突跃之间的氢氧化钠的用量计算了脱乙酰度。该方法具有准确可靠 ,重复性好等优点 ,相对标准偏差小于 0 .9%。 相似文献
19.