光度法间接测定环己基氨基磺酸钠

提出在 0 .0 3mol·L- 1磷酸介质中和 80℃的反应温度下 ,定量的溴与环己基氨基磺酸反应 2 0min后 ,比色法测余溴间接测定环己基氨基磺酸钠的新方法。在测定条件下 ,方法的线性范围为 0～ 0 .5 0mg·ml- 1,检出限为 0 .0 5mg·ml- 1,RSD小于 6 .0 % (n =6 ) ,加标回收率为 90 0 %～99.7%。用于食品添加剂甜蜜素和食品样品的测定 ,结果满意     

胶体滴定法测定羧甲基壳聚糖的取代度

用胶体滴定法测定羧甲基壳聚糖取代度；讨论pH值、溶液浓度、滴定速度和离子强度对胶体滴定的影响，并比较胶体滴定法、电位滴定法和元素分析法的优劣；结果表明胶体滴定法是一种快速、简便地定量测定CMC取代度的方法，且是测定CMC取代度的优选方法。     

N-溴代丁二酰亚胺滴定法测定铁矿石中铁

铁矿石经盐酸溶解后,用Ｈ２Ｏ２氧化,使Ｆｅ＾２＋氧化成Ｆｅ＾３＋。加入过量的ＶＣ还原Ｆｅ＾３＋,剩余ＶＣ用ＮＢＳＭ滴定。方便简便,快速,终点敏锐,精了,准确度高,ＲＳＤ≤０．３％,相对误差〈０．４％,并可选择性地滴定矿石中的三价铁。     

碘量滴定法测定过氧化氢溶液浓度的改进

研究了用碘量滴定法测定过氧化氢浓度时，试剂的加入顺序和放置时间对测定结果的影响。结果表明，在用碘量滴定法测定过氧化氢浓度的过程中，酸化条件下，I^-与H2O2反应的最佳时间为5～10min。与高锰酸钾氧化法相比，碘量法测定效果较好一些。     

化学滴定法测定羟乙基β-环糊精的平均取代度

化学滴定法测定羟乙基β-环糊精的平均取代度     

光度滴定法测定葡萄酒中的总酸

建立光度滴定法用于葡萄酒中总酸含量的测定.试验并讨论了光度电极检测波长、取样体积及酚酞的影响,确定检测波长为640 nm,取样体积为10 mL,酚酞作为指示剂.该方法的检出限为0.07 g/L;6次平行测定值的相对标准偏差为1.15％;3个加标水平的回收率分别为94.0％、92.0％、97.0％.与国家标准规定的电位滴...     

滴定法测定碱金属黄原酸盐

在碱性条件下，CS2和醇反应所生成的有机盐总称黄原酸盐。黄原酸钾(钠)又称乙基黄原酸钾(钠)、乙基二硫代碳酸钾(钠)，为白色或浅黄色固体粉末，有刺激性气味，易溶于水、乙醇中。工业上用作橡胶硫化促进剂，农业上用于作物的干燥剂。黄原酸钠还可作为医用防腐剂及杀菌剂，黄原酸钾是医药甲砜霉素的中间体，也用作分析试剂。     

邻苯二甲酰化壳聚糖中酰胺酸取代度的红外测定

室温条件下从完全脱乙酰化壳聚糖出发合成了不同酰胺酸取代度的邻苯二甲酰化壳聚糖，并以此为标样，标样的取代度由X射线光电子能谱（XPS）确定，研究了以FT－IR作为工具测定此系列衍生物的总取代度的方法，以2887cm^-1的吸收峰作为参比谱带，探针谱带可用1712cm^-1或749cm^-1的吸收峰，两种探针谱带所得曲线的斜率分别为1．13和0．12，相关系数分别为0．997和0．977，此结果表明：红外法是一种既准确可靠又方便可行的测定方法。     

N-1-取代苯并三唑的简易快速合成及生物活性

本文应用相转移催化和微波辐射合成１０个Ｎ－１－取代苯并三唑;Ｎ－１－苄基、－乙氧羰基亚甲基、－芳基、－乙酰基、２个一羧亚甲氧烷基苯并三唑及４个二（苯并三唑基）烷烃,其中有７个为新化合物,这种简易快速方法具有产率高、反应时间短、操作方便、低能耗和无环境污染的优点。初步测试它们的生物活性,大多数化合物具有较好的抗菌活性。     

Acidimetric determination of sodium salts of methyl sulfamic acid

A procedure for the determination of sodium salts of methyl sulfamic acid as tertiary amines by acidimétrie titration in glacial acetic acid was developed. The total error of the procedure did not exceed 1%. The procedure is simple and can be carried out under ordinary laboratory conditions.     

Analytical utility of 2-halopyridinium salts—II Acidimetric determination of thiol groups

2-Chloro-1-methylpyridinium iodide reacts rapidly and quantitatively with thiol groups in the presence of excess of triethylamine to give the 2-alkyl(aryl)thio-1-methylpyridinium iodide and an equimolar amount of hydrogen chloride which is trapped by the triethylamine. The excess of triethylamine is back-titrated with hydrochloric acid, with Bromothymol Blue as indicator.     

The determination of sulfuric acid aerosols

A reliable method has been developed for the chemical determination of sulfuric acid aerosol by simple technique and inexpensive equipment. A similar method is also presented for determining total acidity, including sulfuric acid and volatile acids together with salts that hydrolyze to give protons. The determinations can be performed directly on air samples collected with a sequential tape sampler. The basic chemical reactions involved are specifically controlled by the protons: stoichiometric amounts of bromine are released from a mixture of bromate-bromide by the protons, and the liberated bromine reacts with fluorescein to produce eosin, the color intensity of which is a direct measure of proton concentration. The detection limit for both the methods is 0.5 μg in terms of sulfuric acid and the range for quantitative measurement is 1–10 μg. The new methods are of special significance because of previous lack of reliable methods for determining acidic species in a polluted atmosphere.     

Differential pulse polarographic determination of sulfuric acid

Acetonitrile is used as a solvent for the determination of micromolar amounts of sulfuric acid by differential pulse polarography. Contaminants in the supporting electrolyte and solvent present the biggest problems to the accurate determination of sulfuric acid. The detection limit is 2 × 10^-7 M. Nitric acid. bromide, soluble sulfates, and ammonium hydrogensulfate interfere under certain conditions.     

Vinamidinium salts of N-substituted aminoacetic acids

Formylation of N-phthaloylglycine with the POCl3-DMF system afforded N,N,N′, N′-tetramethyl-2-(N-phthaloyl)vinamidinium perchlorate (2). X-ray diffraction study showed that molecule 2 is planar and contains two equivalent nitrogen atoms in the three-carbon vinamidinium fragment. Salt 2 undergoes transamination with primary aromatic amines to give the corresponding bis-azomethines. The reactions with hydrazines produce substituted 4-aminopyrazoles. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 832–835, May, 2006.     

Purification of baddeleyite concentrate by alloying with sulfuric acid and its salts

The conditions for the sulfation of rough baddeleyite concentrate to remove impurity minerals were studied.     

浓硫酸颜色反应荧光分析法测定甲芬那酸

提出了浓硫酸颜色反应用于甲芬那酸荧光测定的新方法.甲芬那酸为弱荧光物质,与浓硫酸反应后荧光显著增强.体系最大激发波长和最大发射波长分别为385.0和471.9nm,甲芬那酸浓度在9.0×10-9～7.5×10-5 g·mL-1范围内与荧光强度呈良好的线性关系,方法检出限为3.1×10-9 g· mL-1,回收率为99.3％ ～ 102％.方法操作简单,灵敏度高,选择性好,用于甲芬那酸胶囊中甲芬那酸含量测定,结果满意.     

The determination of the second dissociation constant of sulfuric acid

The second dissociation constant of sulfuric acid is determined in 1M NaClO₄ at 25°C using an electrochemical cell without liquid junction consisting of a glass and a perchlorate electrode. By taking into account the association between the Na⁺ and SO ₄ ^2– ions an average value of 0.0184±0.0005 is found using three different methods. This corresponds with an apparent acidity constant KA ₂ ^* of 0.095±0.003     

Quantitative spectrophotometric determination of prodigiozan using phenol in sulfuric acid

Scientific-Research Institute of Pharmacy, Russian Ministry of Health, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, p. 718, November–December, 1992.