原子吸收法间接测定葡萄籽提取物中的原花青素

建立了间接测定葡萄籽提取物中原花青素的原子吸收光谱法。它是基于原花青素能与碱式乙酸铅发生配合反应,产生难溶于水的棕黄色沉淀,经干过滤分离后,用原子吸收法测定滤液中过量的铅离子,可间接测定原花青素。方法线性范围为8.0～80.0μg/mL,回收率为98.1%～102.2%。     

H2O2-Luminol流动注射-抑制化学发光法测定银杏黄酮

基于在碱性条件下,银杏黄酮对H2O2 Luminol体系有显著的抑制作用,结合反相流动注射技术,首次建立了流动注射 抑制化学发光测定银杏提取物中的银杏黄酮。银杏黄酮质量浓度在0.2～20.0μg mL范围与相对发光强度呈线性关系,检出限为0.1μg mL,采样频率为140次 h,对10.0μg mL的银杏黄酮平行测定11次,其RSD为1.5%,回收率为100.0%～100.2%。该方法可用于银杏黄酮制剂的测定。     

ClO--鲁米诺流动注射-抑制化学发光法测定银杏黄酮

基于在碱性条件下,银杏黄酮对ClO--鲁米诺体系有显著的抑制作用,结合反相流动注射技术,建立了流动注射-抑制化学发光测定银杏提取物中的银杏黄酮.银杏黄酮质量浓度在0.4～14.0 μg/mL范围与相对发光强度呈线性关系,检出限为0.06 μg/mL,采样频率为120次/h,对10.0 μg/mL的银杏黄酮平行测定11次,其RSD为1.2%,回收率为98.0%～104%.该方法可用于银杏黄酮制剂的测定.     

CIO^——鲁米诺流动注射-抑制化学发光法测定银杏黄酮

基于在碱性条件下，银杏黄酮对CIO^--鲁米诺体系有显著的抑制作用，结合反相流动注射技术，建立了流动注射．抑制化学发光测定银杏提取物中的银杏黄酮。银杏黄酮质量浓度在0．4～14．0μg/ML范围与相对发光强度呈线性关系，检出限为0．06μg/ML，采样频率为120次／h，对10．0μg／ML的银杏黄酮平行测定11次，其RSD为1．2％，回收率为98、0％～104％。该方法可用于银杏黄酮制剂的测定。     

间接原子吸收法测定黄姜中的薯蓣皂甙元

提出了间接测定黄姜中薯蓣皂甙元的原子吸收光谱法。该法基于薯蓣皂甙元能与碱式醋酸铅发生络合反应,生成难溶于水的白色沉淀,经离心分离后,用原子吸收法测定上清液中过量的铅离子,可间接测定薯蓣皂甙元的含量。该法线性范围为0.0~40.0 mg/L;相对标准偏差(relative standard deviation,RSD)为0.9%~1.1%;回收率为98.9%~102.9%。     

氢化物发生原子吸收法测定卡托普利

根据卡托普利与醋酸铅反应定量生成沉淀的特点 ,通过用氢化物发生原子吸收法测定沉淀中的铅 ,可间接测定卡托普利的含量。平均回收率 99.8% ,RSD值为 1 .6%     

原子吸收光谱法同时测定铅钙锡铝合金中钙和锡

铅钙锡铝合金广泛用于全密封免维护铅蓄电池极板的生产。合金中微量钙的测定有汞分离ＥＤＴＡ容量法[1] ,氯化铅 铜试剂分离ＥＤＴＡ容量法[2 ] ,原子吸收光谱法[3 ] 。锡的测定通常采用邻苯二酚紫 十六烷基三甲基溴化铵吸光光度法[4 ] 。而用原子吸收光谱法测定铅钙锡铝合金中钙和锡的方法还未见报道。科研所研制生产的铅钙锡铝合金中含钙0 0 75 %～ 0 .12 % ,含锡 0 .4 %～ 0 .6 % ,含铝 0 .0 2 %～ 0 .0 3% ,余量为铅。本文用原子吸收光谱法同时测定其中的钙和锡 ,吸收波长分别为 4 2 2 .7和2 86 3ｎｍ。为了防止铅钙锡铝合金中锡水…     

火焰原子吸收光谱法测定铅钡合金中钡

提出了空气-乙炔火焰原子吸收光谱法直接测定铅钡合金中钡的方法.选择HNO3溶样,用基体匹配法消除铅干扰;合金中的杂质成分不干扰测定;方法标准回收率99.4%～100.5%,RSD<1%,适于分析铅钡合金中0.5%～5%的钡.     

微波消解-原子吸收光谱法测定口红中的铅、汞

建立了微波消解–原子吸收光谱法测定口红中铅、汞的方法。以微波消解装置进行口红样品预处理,以石墨炉原子吸收光谱法进行铅含量测定,以冷原子吸收光谱法进行汞含量测定。铅在0.00～2.50 mg/L范围内的线性方程为y=0.022 3x+0.000 8,r=0.999 3,检出限为0.003 mg/L。汞在0～500 ng/L范围内的线性方程为y=400.12x+52.3,r=0.999 9,检出限为6 ng/L。铅、汞测定结果的相对标准偏差分别为0.87%～2.6%,0.65%～2.41%(n=6),加标回收率分别为121%～126%,100%～102%。该方法以单消解方式进行样品前处理,再以该消解液分别进行两种元素含量分析,可提高分析效率,适用于化妆品中金属含量分析。     

石墨炉原子吸收法测定美白化妆品中铅和镉

本文采用石墨炉原子吸收法测定了美白化妆品中铅、镉含量.铅、镉测定的线性范围分别为0～176 ng/mL、0～88 ng/mL,相关系数r均为0.9998,回收率分别为98.2%～101.1%和98.9%～101.8%,相对标准偏差分别为1.73%和1.46%.     

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。     

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.     

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。     

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。     

Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene

Theoretical and Experimental Chemistry - The effect of the method of modification of catalysts based on zeolite X by cesium and magnesium cations (ion exchange and impregnation) on the selectivity...