1-(2-吡啶偶氮)-2-萘酚-过氧化氢光度法测定土壤中痕量钒

对钒(V)与1-(2-吡啶偶氮)-2-萘酚-过氧化氢-十六烷基三甲基溴化铵显色反应进行了试验,结果表明:在1 mol·L-1盐酸介质中,在十六烷基三甲基溴化铵存在下,钒(V)与1-(2-吡啶偶氮)-2-萘酚和过氧化氢反应生成红色多元络合物,络合物的最大吸收波长为577 nm,表观摩尔吸光率为3.04×104L·mol-1·cm-1,钒(V)的质量浓度在1.0 mg·L-1以内符合比耳定律.络合物的组成比为n钒(V):nPAN:n过氧化氢=1:1:1.方法用于土壤试样中痕量钒的测定,测定值的相对标准偏差(n=6)均小于9%,回收率在97.8%～101.5%之间,测得标准样品(GSS-5)中钒的含量为170.45μg·g-1,与标准值(166±9)μg·g-1之间的相对误差为2.7%.     

3-(4''-氯基苯基)-5-(2''-羧基偶氮)若丹宁催化动力学荧光光度法测定痕量锰

研究发现在pH.5.2的邻苯二甲酸氢钾一氢氧化钠缓冲溶液中,Mn(Ⅱ)对过氧化氢氧化3-(4'氯基苯基)-5(2'-羧基偶氮)若丹宁的反应具有强烈的催化作用,并导致荧光强度的增加.据此建立了催化动力学荧光光度法测定痕量锰的方法,荧光强度的增加(△F)与Mn(Ⅱ)的质量浓度在0.014 mg·L-1以内呈线性关系,其线性回归方程为△F=-4.47+1038.75C,相关系数为0.988 6,检出限为1.78×10-6g·L-1.用于自来水和污水样品中痕量锰的测定,测得结果与原子吸收光谱法(AAS)的结果相符.分析结果的相对标准偏差(n=6)均小于2.5%,用标准加入法测得的回收率在95.6%～103.4%之间.     

流动注射-氢化物发生-非色散原子荧光光谱法直接测定海水中的砷(Ⅲ)和砷(Ⅴ)的研究

用流动注射-氢化物发生-非色散原子荧光光谱法对海水中 As(Ⅲ)和As(Ⅴ)的直接测定进行了研究.氢化物发生的最佳条件为:KBH4 溶液浓度为 5 g·L-1(含KOH 5g·L-1),流速 10.0 mL·min-1;样品酸度为1.3mol·L-1 HCl,流速4.2 mL·min-1.对基体 NaCl,MgCl2,CaCl2,Na2SO4以及微量共存金属离子(Cd,Zn,Pb,Cu)的干扰实验结果表明,基体和微量共存金属离子对 As(Ⅲ)的测定没有干扰.样品中As(Ⅴ)的测定用硫脲进行预还原,通过总量和As(Ⅲ)含量的差减得到As(Ⅴ)含量.在优化实验条件下测得方法的检出限(3σ)为0.08 ng·mL-1;7次测定的相对标准偏差为0.48%～1.30%(8.0 ng·mL-1标准溶液).标准曲线和标准加入法对海水样品测定的对照结果表明,两种方法测定结果吻合较好.该方法已应用于近岸海水和大洋海水中As(Ⅲ)和As(Ⅴ)的直接测定.     

镍(Ⅱ)-1-(1吡啶偶氮)-2-萘酚-十二烷基苯磺酸钠体系共振光散射法测定痕量镍

在pH 8.0的Tris-盐酸缓冲介质中,利用十二烷基苯磺酸钠(SDBS)增敏镍(Ⅱ)和1-(2-吡啶偶氮)-2-萘酚(PAN)形成离子缔合物体系,使体系共振光散射增强.体系最大散射波长545 nm,在15～500μg·L-1范围内共振散射增强强度(△I)与镍(Ⅱ)质量浓度呈线性关系.检出限(3S/N)为4.57μg·L-1,分别对50,200,400 μg·L-1镍(Ⅱ)标准溶液进行11次平行测定,测定值的相对标准偏差(n=6)依次为3.5%,3.0%,1.7%.据此提出了一种简单而快速的测定镍的方法.应用于测定水样中镍量,测得其平均回收率为98.5%.     

1-(4-安替比林)-3-(3-硝基苯胺)三氮烯分光光度法测定镉(Ⅱ)

合成了一种新的显色剂三氮烯试剂1-(4-安替比林)-3-(3-硝基苯胺)三氮烯(ANTA),并研究了该显色剂与镉(Ⅱ)的显色反应。在Tween-80存在下及pH 10.2的硼砂-氢氧化钠缓冲溶液中,显色剂ANTA与镉(Ⅱ)形成2∶1的稳定络合物。其最大吸收波长位于508 nm波长处,表观摩尔吸光率为3.4×105L.mol-1.cm-1。镉(Ⅱ)的质量浓度在30.0~450μg.L-1范围内符合比耳定律,方法的检出限(3σ/k)为10.0μg.L-1。方法用于废水样品中微量镉(Ⅱ)的测定,测定结果与原子吸收光谱法相一致,平均回收率为103.5%,平均相对标准偏差(n=6)为4%。     

2-(2-喹啉偶氮)-1,5-二氨基苯固相萃取光度法测定痕量钯

根据2-(2-喹啉偶氮)-1,5-二氨基苯(QADAB)与钯的显色反应及MCI-GEL反相固相萃取小柱对显色络合物的固相萃取,建立了一种测定痕量钯的方法.在0.2～3.0 mol·L-1高氯酸介质中,溴化十六烷基三甲胺(CTMAB)存在下,QADAB与钯反应生成2:1稳定络合物,该络合物可被MCI-GEL反相固相萃取小柱萃取富集,富集的络合物用丙酮洗脱后用光度法测定,在丙酮介质中体系的最大吸收波长为600 nm,表观摩尔吸光率为9.63×104L·mol-1·cm-1.钯质量浓度在0.01～L 5 mg·L-1内符合比耳定律,方法用于几种实样中痕量钯的测定,测得回收率在86%～96%间.     

槲皮素-镓(Ⅲ)-十二烷基磺酸钠荧光体系及其在测定中药槐米、银杏叶、陈皮中黄酮的应用

在微酸性的酸度条件下,在SLS介质中镓(Ⅲ)与槲皮素形成n[镓(Ⅲ)]n(槲皮素)=11的黄色荧光络合物,激发波长为435.4 nm,发射波长为485.6 nm,槲皮素的浓度在4.0×10-7～3.2×10-6mol·L-1范围内与荧光强度呈线性关系,检出限为1.79×10-10mol·L-1.用该方法分析了几种中药,测定结果的RSD(n=8)值在0.23%～0.64%之间,回收率在90.1%～101.3%之间.     

琉基葡聚糖凝胶分离富集-1-(4-安替比林)-3-(2,4,6-三溴苯基)-三氮烯光度法测定痕量镍(Ⅱ)

合成并鉴定了一种新的三氮烯试剂1-(4-安替比林-)3-(2,4,6-三溴苯基)-三氮烯(ABPT),研究了该试剂与镍(Ⅱ)的显色反应条件。在pH 10.0的硼砂-氢氧化钠介质中,在Triton X-100存在下,ABPT与镍(Ⅱ)发生灵敏的显色反应。络合物的最大吸收波长为515nm,表观摩尔吸光率为2.1×105L.mol-1.cm-1。镍(Ⅱ)质量浓度在20.0～400μg.L-1之间呈线性,检出限(3s/k)为8μg.L-1,方法用于生活垃圾、水样品中痕量镍(Ⅱ)的测定,结果与原子吸收光谱法的测定结果相符,测定值的相对标准偏差(n=6)均小于5%,回收率在102.5%～105.0%之间。     

氢化物发生-原子吸收光谱法测定锑(Ⅲ)和锑(Ⅴ)

提出在酸性条件下以氟化钠为掩蔽剂测定锑(Ⅲ),在碱性介质中加入氟化钠消除价态的影响测定锑总量,两者相减求出锑(Ⅴ),实现对锑(Ⅲ)和锑(Ⅴ)的分别测定.研究了在酸性介质中测定锑(Ⅲ)及碱性介质中测定锑总量的条件及共存离子的干扰和消除.工作曲线的线性范围为：0～20 μg·L-1锑(Ⅲ);0～80 μg·L-1锑(Ⅴ),相关系数大于0.999,方法的检出限为0.31 μg·L-1锑(Ⅲ),0.69 μg·L-1锑(Ⅴ).对水样和土壤样品进行了测定,相对标准偏差(RSD)小于5%.     

氢化物发生-原子荧光光谱法对环境水样中砷(Ⅲ)与砷(Ⅴ)的直接测定

建立了氢化物发生-原子荧光光谱直接测定水样中As(Ⅲ)和As(Ⅴ)的方法,操作简便,实用性强.考察了HCl和KBH4浓度对As(Ⅲ)和As(Ⅴ)测定灵敏度的影响以及共存元素的干扰情况.通过测定经还原剂还原前后水样中砷的荧光强度,计算出As(Ⅲ)和As(Ⅴ)的含量.方法检出限为As(Ⅲ) 0.085 μg·L-1 ,As(Ⅴ) 0.108 μg·L-1.As(Ⅲ)和As(Ⅴ)的加标回收率分别为96% ～104%和97% ～104%,RSD均小于6%.该法用于实际水样的测定,结果较为满意.     

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.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

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.     

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.     

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.