钒酸铵氧化-分光光度法测定盐酸氯丙嗪

在磷酸介质中,钒酸铵与盐酸氯丙嗪反应生成红色氧化产物,其最大吸收波长为524nm;据此建立了测定盐酸氯丙嗪含量的钒酸铵氧化-分光光度法,并将其用于直接测定药物制剂中的盐酸氯丙嗪.结果表明,当盐酸氯丙嗪的浓度处于10.0～100mg/L和100～360mg/L范围内时,被测定体系的吸光度与盐酸氯丙嗪的浓度之间呈良好的线性关系;线性回归方程分别为A=-0.061 69+0.010 05c(mg/L,r=0.998 8)、A=0.494+0.004 43c(mg/L,r=0.998 8),检出限为1.96mg/L,相对标准偏差为0.29%,回收率为94.9%～102.9%.     

FeCl3-铁氰化钾体系分光光度法测定酚磺乙胺

采用铁氰化钾-FeCl3体系分光光度法测定酚磺乙胺。研究表明,酚磺乙胺可使Fe(Ⅲ)还原为Fe(Ⅱ),还原生成的Fe(Ⅱ)可以与K3[Fe(CN)6]反应生成可溶性普鲁士蓝KFe[Fe(CN)6],其最大吸收波长位于710 nm处。酚磺乙胺的质量浓度在0.064～9.6 mg/L范围内与吸光度呈现良好线性关系,线性回归方程A=0.03242+0.08244ρ(mg/L),相关系数r=0.9994,摩尔吸光系数ε=2.17×104L/(mol·cm),检出限0.047 mg/L;相对标准偏差(3.20 mg/L,n=11)为2.4%。方法用于测定药物注射液中酚磺乙胺含量,回收率为98.3%～102.9%。     

磷钼蓝可见分光光度法测定左旋多巴的含量

本文建立了磷钼蓝可见分光光度法测定左旋多巴含量的方法。实验表明:磷钼杂多酸([H2PMo12O40]-)被左旋多巴还原生成磷钼蓝(H3PO4.10MoO3.Mo2O5),左旋多巴在0.40～12.00μg.ml-1浓度范围内与磷钼蓝的吸光度呈现良好的线性关系,线性回归方程为:A=0.044+0.03963c(μg·mL-1),线性相关系数R=0.9988,表观摩尔吸光系数ε=8.64×103L·mol-1cm-1,其最大吸收波长λmax=710 nm,检出限为0.17μg·mL-1。本法用于左旋多巴片剂含量的测定,平均回收率为100.2%,相对标准偏差不大于0.34%,结果满意。     

催化光度法测定水中痕量汞

痕量汞的存在对在稀硝酸介质中亚铁氰化钾及1,10-二氮菲之间的反应有明显的催化作用,在508 nm波长处测定催化体系及非催化体系的吸光度A及A0并计算其吸光度差△A,该体系的△A与相应汞的质量浓度从2.0×10-3～6.4×10-2 mg·L-1之间呈线性关系(r=0.987 6),其摩尔吸光率为5.92×105 L·mol-1·cm-1.对一件水样按此方法测定其汞含量,测得结果的RSD(n=6)值为0.134%.按标准加入法进行了回收率试验,所得结果在97.5%～102.7%之间.     

铁氰化钾化学发光体系测定利福平的研究

基于在NaOH碱性介质中 ,铁氰化钾可以直接氧化利福平产生化学发光这一现象 ,结合流动注射分析技术 ,提出了一种直接利用化学发光测定利福平的新方法。该方法测定利福平的线性范围为 0 .1～ 30mg/L ,检出限为 0 .0 6mg/L ,相对标准偏差为 3.0 % (n =1 1 ,ρ(利福平 ) =1 .5mg/L) ,方法已成功地用于胶囊及滴眼液利福平样品的分析     

左旋多巴荷移反应及其光谱性质研究

研究了发生在左旋多巴与电子受体四氯对苯醌(TCBQ)之间的荷移反应。实验结果表明,左旋多巴与四氯对苯醌在硼砂缓冲液中可生成稳定的1∶1型络合物,其λmax=348 nm,表观摩尔吸光系数ε=6.2×103L.mol-1.cm-1,左旋多巴在0~26.4μg/mL范围内与分析信号呈线性关系。回收率为98.03%~100.3%,相对标准偏差在2.3%以内。应用本法测定了左旋多巴片剂的含量,结果与文献方法一致。     

流动注射化学发光测定水中的苯酚

基于苯酚对鲁米诺－铁氰化钾化学发光体系有增敏作用，建立起测定苯酚的新方法。苯酚浓度在0.01-10mg/L范围内与化学发光强度呈良好的线性关系，标准曲线为△I=307.44C(mg/L)-36.929(n=9,r^2=0.9983），检出限（3σ）为0.004mg/L，对1mg/L的苯酚进行11次平行测定，相对标准偏差（RSD）为1.06%。本法已用于废水中苯酚的测定。     

1, 2-萘醌-4-磺酸钠分光光度法测定间苯二酚

在pH 13.00缓冲溶液中, 间苯二酚能够催化氢氧根离子与1,2-萘醌-4-磺酸钠反应生成2-羟基-1, 4-萘醌, 其最大吸收波长为454 nm. 间苯二酚质量浓度在0.39～13.21 mg/L范围内与吸光度呈现良好线性关系. 线性回归方程为A=0.01918+0.05703c (×105 mol/L), 相关系数r=0.9981. RSD和检测限分别为1.6%, 0.34 mg/L (3σ/k). 该法能够直接用于水样中间苯二酚含量测定, 回收率在94.3%～106%.     

流动注射化学发光法测定水中的苯酚

基于苯酚对鲁米诺 铁氰化钾化学发光体系有增敏作用 ,建立起测定苯酚的新方法。苯酚浓度在0 0 1～ 10mg L范围内与化学发光强度呈良好的线性关系 ,标准曲线为ΔI =30 7.44C(mg L) - 36 .92 9(n =9,r2 =0 .9983) ,检出限 (3σ)为 0 .0 0 4mg L ,对 1mg L的苯酚进行 11次平行测定 ,相对标准偏差 (RSD)为 1.0 6 %。本法已用于废水中苯酚的测定。     

分光光度法测定盐酸多巴胺的含量

研究了氨水溶液中,FeCl3与盐酸多巴胺反应生成紫红色络合物,其最大吸收波长为507 nm,络合比为1∶2.体系的吸光度与盐酸多巴胺的浓度在20.0～220 mg/L范围内呈良好的线性关系,线性回归方程A=0.00842+0.11844 ρ(mg/L),相关系数r=0.9991,表观摩尔吸光系数ε=2.25×104L·...     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.