铜-铬天青S-十二烷基苯磺酸钠褪色光度法测定痕量钡

1　引　　言测定痕量钡有Ｂａ 偶氮氯膦 Ｃｕ 邻菲咯啉 (ｐｈｅｎ) (ε≈ 1.0× 10 5Ｌ·ｍｏｌ- 1 ·ｃｍ- 1 )、Ｂａ 偶氮氯膦 Ｚｎ Ｐｈｅｎ(1.8×10 5Ｌ·ｍｏｌ- 1 ·ｃｍ- 1 和Ｂａ 联吡啶 间溴偶氮酸 (1.5× 10 5Ｌ·ｍｏｌ- 1 ·ｃｍ- 1 )等多元离子缔合光度法 ,邻氨基苯磺酸Ｓ、偶氮胂ＩＩＩ、金属钛和二苯卡巴腙 (检出限 :均约为 10 - 6ｇ ｍＬ)等光度分析法 ,以及催化褪色光度法 (4 .0× 10 - 1 1 ｇ ｍＬ)等。实验观察到 ,在ｐＨ =5 .40弱酸性介质中和加热条件下 ,钡能使 [Ｃｕ(Ｒ) 4]2 +·[(ＤＢＳ) 2 ]2 - (Ｒ为铬天…     

二安替比林甲烷光度法测定工业硅中钛

工业硅中杂质元素的测定 ,一般只测定其中的铁、铝、钙含量[1,2 ] 。在近年的出口工业硅检验中 ,对钛也提出检测要求。本法采用二安替比林甲烷光度法[3 ] 测定工业硅中钛 ,方法简便、稳定 ,结果准确。1　试验部分1.1　仪器与试剂ＴＵ 190 1分光光度计 (北京普析通用仪器公司 )Ｔｉ(Ⅳ )标准溶液 :0 .1ｍｇ·ｍｌ- 1,称取高纯二氧化钛 0 .16 6 8ｇ于铂金坩埚中 ,加焦硫酸钾 5～ 7ｇ于6 0 0℃熔融 ,冷却 ,用Ｈ2 ＳＯ4 (5 + 95 ) 10 0ｍｌ浸提熔块后移入 1Ｌ容量瓶中 ,并以Ｈ2 ＳＯ4 (5 + 95 )稀至刻度。使用时再稀释成 5 μｇ·ｍｌ- 1标准工…     

硅钼蓝光度法测定五氧化二钒中微量硅

采用氢氧化钠对试样进行前处理 ,在硝酸 0 .0 8～ 0 .4 0ｍｏｌ·Ｌ- 1酸度下 ,硅与钼酸铵形成硅钼酸络离子 ,在硫酸 0 .8～ 1.6ｍｏｌ·Ｌ- 1酸度下 ,被还原生成硅钼蓝 ,借此进行光度测定[1] ,硅量在 10～ 10 0 μｇ/5 0ｍｌ范围内遵守比耳定律。1　试验部分1.1　仪器与试剂72 2光栅分光光度计硅标准溶液 :10 μｇ·ｍｌ- 1五氧化二钒标准溶液 :2 .5ｍｇ·ｍｌ- 1,称取五氧化二钒 (99.99%) 0 .2 5 0 0 ｇ置于 30 0ｍｌ聚四氟乙烯烧杯中 ,加入 10 0ｇ·Ｌ- 1ＮａＯＨ溶液 10ｍｌ,低温加热溶解 ,取下 ,加入数滴酚酞 ,用ＨＮＯ3 (1+ 1)调至无…     

吸光光度法测定空气中一甲胺的改进

车间空气中一甲胺的测定 ,目前推荐的方法仅为对硝基苯胺重氮盐比色法[1] ,作者在工作中发现 ,该法中对硝基苯胺重氮盐溶液的加入量对其影响很大 ,为此 ,进行了一系列探讨并加以改进。1　试验部分1.1　仪器与试剂72 1型分光光度计吸收液 :0 .0 1ｍｏｌ·Ｌ- 1盐酸溶液缓冲液 :80ｍｌ蒸馏水内溶解 4 .0 8ｇ磷酸二氢钾、1.6ｇ硼砂 ,再加入 5 .0ｍｏｌ·Ｌ- 1氢氧化钠溶液 6.35ｍｌ,用水稀释至 10 0ｍｌ亚硝酸钠溶液 :5 .0 ｇ·Ｌ- 1对硝基苯胺盐酸溶液 :1.0 ｇ·Ｌ- 1,将 0 .1ｇ对硝基苯胺溶于 1.0ｍｏｌ·Ｌ- 1盐酸 10 0ｍｌ中。对硝基苯胺重…     

火焰原子吸收光谱法测定粗杂铜中锑

在铜冶炼的全过程中都要对锑进行分析。方法主要有比色法、滴定法、共沉淀分离原子吸收光谱法 ,但分析方法都较繁琐[1] 。本法试验在锑不水解的情况下 ,不分离基体铜 ,直接用原子吸收光谱法测定粗杂铜中锑。并对样品分解、元素干扰作了试验 ,对方法的准确度、精密度作了考查 ,取得满意结果。1　试验部分1.1　主要试剂与仪器酒石酸溶液 :10 0 ｇ·Ｌ- 1锑标准溶液 :5 0 0 μｇ·ｍｌ- 1,称取金属锑(99 99%以上 ) 0 .5 0 0 0 ｇ于 2 0 0ｍｌ烧杯中 ,加酒石酸 5 ｇ ,硝酸 30ｍｌ,低温溶解完全 ,赶尽氮的氧化物 ,冷却后用水移入 1Ｌ容量瓶中定容…     

阳极溶出伏安法测定痕量汞的研究

痕量汞的测定方法有很多[1 ] 。原子吸收法虽然具有较高的灵敏性 ,但是仪器设备昂贵 ,分析步骤较繁琐。近年来 ,化学修饰电极阳极溶出伏安法在对汞痕量分析方面的研究报道也不少[2～3] ,测定的检测限一般在 1 0 - 6～ 1 0 - 9ｇ·ｍｌ- 1 ,但它容易产生记忆效应 ,洗脱不良。本文以玻碳电极为工作电极 ,在ＨＣｌ ＮａＣｌ Ｃｄ2 +中 ,示差脉冲阳极溶出伏安法 (ＤＰＳ)测定痕量汞 ,汞的平均回收率达80 %。1　实验部分1 1　主要仪器与试剂ＰＡＲ— 384极谱仪 (美国 ) ;三电极系统 :工作电极为玻碳电极 ,参比电极为Ａｇ/ＡｇＣｌ电极 ,对电极为…     

偶氮氯膦Ⅰ光度法测定镁

测定铜矿中镁的方法不少[1] ,但均存在一些不足之处。本文采用光度法测定镁的显色剂为偶氮氯膦Ⅰ (ＣＰＡ Ⅰ ) ,于ｐＨ 10左右的硼砂 氢氧化钠缓冲液中显色 ,试验表明 ,方法的准确度和精密度能满足分析要求。1　试验部分1.1　主要仪器与试剂75 4型分光光度计镁标准溶液 :10 μｇ·ｍｌ-1,称取于 60 0℃灼烧 1ｈ后的高纯氧化镁 0 .10 0 0ｇ于烧杯中 ,加ＨＣｌ(1+ 1)10ｍｌ,盖表皿 ,低温溶解后 ,加水定容于 1Ｌ容量瓶中 ,吸取溶液 5 0ｍｌ,加水稀至 5 0 0ｍｌ容量瓶中。显色剂 :0 .30 0 0ｇ·Ｌ-10 .30 0ｇＣＰＡ Ⅰ溶于 1Ｌ水中氢氧化钠 …     

负催化动力学光度法测定溴的研究

本文报道了溴 ( Br- )对溴酸钾氧化甲基橙 ( MO)褪色反应的负催化作用及其动力学分析 ,建立了测定痕量溴的新方法。方法的检出限达到 1 .0× 1 0 - 9g/ m L,线性范围 0 .5～ 1 .8ng/ m L,表观摩尔吸光系数 1 .0× 1 0 6 L·mol- 1·cm- 1。用于井水 ,精盐中痕量溴的测定 ,结果满意     

铁矿中全铁、二氧化硅和氧化钙的测定

铁矿的质量检查和入炉铁矿全铁、二氧化硅和氧化钙的测定 ,是中小型铁厂化验室相当繁重的一项日常工作 ,表现为试样数量多 ,测试频率高 ,同时要求较快地报出结果。采用既经济又快速实用的分析方法 ,对指导高炉生产有着十分重要的意义。1　试验部分1.1　主要仪器与试剂72 1ＳＸ分光光度计钨酸钠溶液 :5 0ｇ·Ｌ- 1,称取Ｎａ2 ＷＯ4 ·2Ｈ2 Ｏ 5ｇ溶于 5 0ｍｌ水中 ,加磷酸 10ｍｌ,用水稀释至 10 0ｍｌ ,摇匀。三氯化钛溶液 :将 15 0～ 2 0 0ｇ·Ｌ- 1三氯化钛用盐酸 (1+ 1)稀释 3倍硫酸铜溶液 :2 0ｇ·Ｌ- 1硫 磷混酸 :Ｈ2 ＳＯ4 ∶Ｈ2 ＰＯ…     

悬浮物溶解光度法测定痕量钛

1　引　　言测定Ｔｉ 的方法有二溴羟基荧光酮 曲拉通Ｘ 1 0 0胶束荧光熄灭法、电解法、液芯光纤光度法、小波变换三波长系数倍率法等。以悬浮物溶解光度法测定某些痕量金属离子已有文献报道 ,但用此法测定痕量Ｔｉ 未见报道。基于在ｐＨ =4 .5～6.0的弱酸性介质中 ,Ｔｉ 能与曙红及Ｂｒ- 生成沉淀 ,从而提出了悬浮物溶解光度法测定痕量Ｔｉ 的新方法 ,该方法简便快速、重现性好、选择性强、灵敏度高 (ε530 =2 .5 4× 1 0 7Ｌ·ｍｏｌ- 1 ·ｃｍ- 1 ) ,检出限为 8.2× 1 0 - 8ｇ Ｌ ,并成功用于头发中痕量Ｔｉ 的测定。2　实验部分2 .1　仪…     

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.     

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。