钛-间硝基苯基荧光酮-表面活性剂显色体系的研究及应用

系统地研究了钛与间硝基苯基荧光酮的显色反应,试验了多种表面活性剂对显色体系的作用,确定了最佳显色体系为Ti(Ⅳ) m NPF Tween 60 PVA,在pH为1.85～2.20的盐酸介质中形成的红紫色络合物,ε541=1.37×105L·mol-1·cm-1,不经分离直接测定了合金钢中的微量钛,结果满意。     

铅(Ⅱ)-DBONBF-CTMAB吸光光度法测定铅

邻硝基苯基荧光酮属于三羟基荧光酮显色剂,已用于多种元素的光度分析[1]。本文对其衍生物4,5 二溴邻硝基苯基荧光酮(DBONBF)与铅(Ⅱ)的反应进行了研究。试验表明,该反应的灵敏度较高(ε可达1.6×105L·mol-1·cm-1),体系的选择性与稳定性较好,可用于工业废水中铅的测定。1　试验部分1.1　试剂与仪器铅标准溶液:1.0g·L-1,10μg·ml-1DBONBF乙醇溶液(AR级):0.4g·L-1CTMAB溶液:2g·L-1NH3 NH4Cl缓冲溶液:pH9.6721型分光光度计(上海第三分析仪器厂)1.2　试验方法于25ml容量瓶中加入含10μg铅的标准溶液,再依次加入DBONBF乙…     

二阶导数光谱峰面积法测定中草药中微量锗

在Ge 苯基荧光酮 (PF) 氯化十六烷基吡啶 (CPC)三元络合物的显色体系中 ,引入二阶导数光谱峰面积技术 ,对锗的显色体系及测定方法进行了研究。该方法有效地消除了W 、Sn 、Mo 、V 、Ti 和Fe(Ⅲ )等离子的干扰 ,提高了准确度和选择性。线性范围为 0～ 1 5mg L,检出限为 3 .3 μg L ,εGe为 1 .4× 1 0 5L·mol- 1 ·cm- 1 。用于中药材中Ge 的测定 ,标准加入试验的回收率为 1 0 1 .0 %～ 1 1 2 .0 %。     

新型显色剂2,3,7-三羟基-9-(3,5-二氯-4-羟基)苯基荧光酮与钨(Ⅵ)的显色反应

研究了在阳离子表面活性剂溴化十六烷基三甲胺(CTMAB)存在下 ,新试剂2,3,7_三羟基_9_(3,5_二氯_4_羟基)苯基荧光酮(DCHPF)与钨(Ⅵ)的显色反应及光度性能 ;在0.6mol/LHCl介质中 ,试剂与钨(Ⅵ)形成化学计量比为2∶1的红色络合物 ,其最大吸收峰位于536nm波长处 ,表观摩尔吸光系数为1.28×105L·mol-1·cm-1,钨含量在0～0.4mg/L范围符合比尔定律 ;拟定分析方法用于钢样中微量钨的测定 ,结果令人满意。     

铜矿石中微克量钨的测定

本法以邻-硝基荧光酮作显色配体,以乳化剂OP胶束增溶,所形成的钨(Ⅳ)-邻硝基荧光酮-OP-三元络合物组成比为1:3:4,最大吸收位于510nm,其ε_(510nm)为1.3×10~5,钨的浓度(以WO_3计)在0—2.5μg/mL符合比尔定律。一般常见元素不干扰测定,Ge(Ⅳ)、Sn(Ⅳ)、Sb(Ⅴ)、Mo(Ⅵ)严重干扰测定,铜矿中这些元素极微,且用盐酸处理试样时锗和锑呈氯化物逸出,故其影响可消除。试剂及仪器钨标准溶液:称取0.1000g优级纯三氧化钨溶于20mL 0.5mol/L氢氧化钠溶液中,并     

3,5—二溴—4—氨基苯基荧光酮与钨显色反应的研究及应用

研究了在表面活性剂CTMAB存在下,钨与3,5-二溴-4-氨基苯基荧光酮形成配合物的显色反应和光度性质,在HCl 0.2～0.8mol·L~(-1)介质中,波长为523nm处测得配合物的表观摩尔吸光系数为1.21×10~5,钨含量在0～12μg/25ml范围内符合比耳定律。体系灵敏度较高,大多数常见阳离子不干扰钨的测定,拟定方法用于合金钢中微量钨的测定,结果满意。     

2-羟基-3-甲氧基苯基荧光酮分光光度法测定中药中痕量锗

研究了新试剂2羟基3甲氧基苯基荧光酮(HMPF)与锗的显色反应。建立了测定几种中药中锗的光度分析方法。在磷酸(2+1)介质和非离子型表面活性剂OP介质中,2羟基3甲氧基苯基荧光酮与锗发生灵敏的显色反应,其最大吸收峰为505.50nm,表观摩尔吸光系数为1.56×105L·mol-1·cm-1,锗量在0～12μg/25mL符合比耳定律。锗与试剂的显色反应有良好的选择性,绝大多数金属离子特别是钙、镁、铁、锌和钼有非常高的允许量,可直接应用于几种中药中锗的测定,结果满意。     

微乳液增敏对硝基苯基荧光酮光度法测定人发中痕量镍

研究了微乳液介质中,在pH等于10.4时,镍与对硝基苯基荧光酮(p-NPF)显色生成稳定的1∶3配合物,在600nm处摩尔吸光系数为1.64×105L/(mol·cm),镍含量在0～0.7μg/mL范围内符合比耳定律,采用巯基葡聚糖凝胶分离富集,消除了共存离子的干扰,用所拟方法测定人发中的痕量镍,结果令人满意.     

用若丹明B光度法测定石煤渣中微量钒

研究了痕量V(Ⅴ)催化KBrO3 氧化还原型若丹明B(RRhB)的显色反应 ,建立了光度法测定石煤渣中痕量V(Ⅴ)的新方法。结果表明在抗坏血酸存在下具有高灵敏的显色反应 ,摩尔吸光系数为3.8×105 L·mol-1·cm-1,显色程度与V(Ⅴ)量在0～100μg/L范围内符合比耳定律。该法用于测定石煤渣中的微量V时 ,结果令人满意。     

微乳液-SAF吸光光度法测定汽油中环烷酸铁

研究了在溴化十六烷基三甲基铵(CTMAB)/正戊醇/正庚烷/水组成的阳离子型微乳液中Fe(Ⅲ)与水杨基荧光酮(SAF)的显色反应。结果表明,微乳液对Fe(Ⅲ)SAF显色体系有一定的增敏作用。在pH9.8～10.3的硼砂缓冲溶液中,经30℃水浴加热10～15min,Fe(Ⅲ)SAF在微乳液介质中形成稳定的有色配合物,ε600达1.23×105L·mol-1·cm-1,而Fe(Ⅲ)SAF在CTMAB胶束体系中,ε600为1.11×105L·mol-1·cm-1,Fe(Ⅲ)浓度在0～5μg/25mL范围内遵守比耳定律,由于微乳液的特殊组成,可用于汽油中环烷酸铁的测定,结果满意。     

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.     

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。     

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...     

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.     

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.     

Synthesis of tetrabenzoporphins of the basis of isoindoline

Chemistry of Heterocyclic Compounds -