在非离子表面活性剂存在下用3,5-diBr-PADAP 光度法测定锌、镉

2-(3,5-二溴-2-吡啶偶氮)-5-二乙氨基苯酚(3,5-diBr-PADAP)是目前偶氮染料中灵敏度较高的有机显色剂之一,曾用于各种元素的测定,迄今为止,尚未发现有人用此试剂连续测定锌、镉。本文研究了在非离子表面活性剂平平加(Peregal O)存在下,锌、镉与3,5-diBr-PADAP的显色反应,发现在此体系中Zn-3,5-diBr-PADAP,Cd-3,5-diBr-PADAP配合物的最大吸收波长接近,显色反应的最佳酸度范围也基本一致,根据吸光     

贵金属合金中铟的定量萃取

Stralow等人曾提出在盐酸-丙酮介质中,离子交换色层法进行铟与多种金属离子的分离,对Au(Ⅲ)、pt(Ⅳ)、pd(Ⅱ)、Rh(Ⅲ)等与In(Ⅲ)的离子交换色层分离也作了评价,但对Ir(Ⅲ)、Ir(Ⅳ)、Ag(Ⅰ)的分离未做定量研究。萃取分离在微量铟的分析中早有应用,本文对在盐酸和氢溴酸介质中用乙酸乙酯(EAc)从多种金属离子中定量萃取分离铟的条件进行了实验。结果表明,在3.5—5.5M HBr介质中EAc能定量萃取In(Ⅲ),并与Pt(Ⅳ)、Pd(Ⅱ)、Rh(Ⅲ)、Ir(Ⅳ)、     

2-[(3,5-二溴-2-吡啶)偶氮]-5-二乙氨基苯酚分光光度法测定岩石中微量镓

本文拟定在pH4的醋酸-醋酸钠缓冲体系中,当有丙酮存在下,镓与2-〔(3,5-二溴-2-吡啶)偶氮〕-5-二乙氨基苯酚(简称3,5-diBr-PADAP)可形成较稳定的红色络合物。该络合物于波长580nm有最大吸收,表观摩尔吸光系数达1.0×15~5,测定络合物组成比为Ga:3,5-diBr-PADAP=1:2.25ml体积中含Ga 0-10μg遵从比尔定律。采用碱熔分离和     

3,5-diBr-PADAP作锆(Ⅳ)显色剂的分光光度法研究与应用

本文研究了在非离子表面活性剂存在下,用3,5-diBr-PADAP作锆显色剂的胶束增溶分光光度法。在pH1.0～2.0的HCl介质中,配合物吸光度最大且稳定,最大吸收值在610nm处。Zr(Ⅳ)与试剂形成1:2的配合物,摩尔吸光系数为1.10×10~5L·mol~(-1)·cm~(-1),zr(Ⅳ)量在0～30μg/25mL范围内遵守比尔定律。采用钽试剂一苯苹取分离法,适合于钽铌矿中微量锆的测定。     

用2-(3,5-二溴-2-吡啶偶氮)-5-二乙氨基苯酚分光光度法测定岩石、土壤、铬铁矿、铝土矿中的钒

有关岩石矿物中钒的测定方法共存元素的允许量较小,有的也不够灵敏。为此,本文着重研究了52种离子的可能影响,提出用CyDTA-氟化钠为掩蔽剂及在碱性介质中加入硫酸肼消除共存元素干扰,提高了方法的选择性。在0.5-0.6N硫酸介质中,过氧化氢存在下,钒与过氧化氢及2(3,5-二溴-2-吡啶偶氮)-5-二乙氨基苯酚(3,5-diBr-PADAP)形成橙红色的三元络合物。有色络合物至少可稳定24小时,其λ_max=605nm,ε_(605)=5.68×10~4,0.04-25微克五氧化二钒/毫升服从比尔定律。可用于测定岩石、土壤、铬铁矿及铝土矿中0.001-1.0％的钒。一、试剂配制钒标准溶液称取0.1000克光谱纯五氧化二钒,     

铟(Ⅲ)与桑色素共存时电化学行为的研究和分析应用 Ⅱ.桑色素及其与铟(Ⅲ)共存时电极反应过程

桑色素(H_5L),铟(Ⅲ)在盐酸-氯化钾(pH2.2～2.6)溶液中,分别以 H_4L~-及In(H_2O)_4Cl(_2~+)形态存在,但未形成缔合物,在电极表面,H_4L~-吸附诱导 In(H_2O)_4Cl(_2~+)与之形成缔合物,使 In(Ⅲ)还原电流增敏,文中提出了桑色素及其与铟(Ⅲ)共存时(pH2.4)各自的电极反应机理,对阴离子表面活性剂的增敏作用也进行了探讨。     

铟(Ⅲ)-2-巯基苯骈噻唑-7-碘-8-羟基喹啉-5-磺酸三元络合物吸附波研究

在HCl-NaAc介质(pH 2.5)中,用单扫示波极谱法可获得高灵敏的In(Ⅲ)-2-疏基苯骈噻唑(MBT)-7-碘-8-羟基喹啉-5-磺酸(Ferron)三元络合物吸附波.峰电位在—0.64V(vs.SCE),峰电流与铟浓度在7.0×10~(-10)mol/L～8.8×10~(-7)mol/L之间呈线性关系.检出限可达3.0×10~(-10)mol/L.测得电活性络合物的组成为In(Ⅲ):MBT:Ferron=1:1:1.研究了极谱波的性质和机理.本法选择性较好,用于工业废水和地下水中痕量铟的测定,结果满意.     

In(Ⅲ) -NCP体系配位吸附波研究及应用

在0.15 mol/L HAc-NaAc(pH 3.2)介质中,In(Ⅲ)-NCP(2,9-二甲基邻菲咯啉)配合物在2.5次微分极谱图上产生良好的吸附还原波.其峰电位为-0.40 V,峰电流与In(Ⅲ)浓度在4.0×10-8～2.0×10-6 mol/L范围内呈良好的线性关系,检出限为8.0×10-9 mol/L.应用该法测定了氢氧化铝和陶瓷颜料中的微量铟,结果满意.研究了配合物的组成、极谱波的性质及其机理.     

铀-2-(3,5-二溴-2-吡啶偶氮)-5-二乙氨基苯酚-Triton X-100析相体系的研究及应用

本文研究了铀-2-(3,5-二溴-2-吡啶偶氨)-5-二乙氨基苯酚(3,5-diBr-PADAP)-Triton X-100析相光度体系,建立了矿石中微量铀的测定方法,在pH 7.5三乙醇胺-盐酸介质中,将胶束溶液在 95±1℃加热 1h.络合物即被Triton X-100相完全富集.络合物最大吸收峰位于565nm.摩尔吸光系数为1.02×10～5L·mol～(-1)·cm～(-1),铀含量在0～12μg/5mL服从比耳定律.采用TBP萃淋树脂分离干扰离子,测定矿石中微量铀,结果满意.     

二甲庚基乙酰胺(N503)自盐酸溶液中萃取铟的研究

本工作研究了二甲庚基乙酰胺(N₅₀₃)自盐酸溶液中萃取铟的性能,得出其萃取能力随着酸度的增加而增加。经斜率法和化学分析法确定,N₅₀₃自盐酸溶液中萃取铟的反应为: 萃合物中的溶剂化数n随酸度而变化。IR和NMR研究证明,铟是以HInCl₄形式被N₅₀₃萃入有机相的。在盐酸体系中(HCl<2N),N₅₀₃对镓、铟、铊的萃取顺序为:Tl(Ⅲ)>Ga(Ⅲ)>In(Ⅲ)     

Copolymers of tetrafluoroethene with chlorotrifluoroethene and with bromotrifluoroethene

Tetrafluoroethene (TFE)–chlorotrifluoroethene (CTFE) and TFE–bromotrifluoroethene (BTFE) copolymers have been synthesized by solution copolymerization over the entire range of comonomer composition. Crystallinity data are reported and first- and second-order transitions have been investigated by DSC. Glass transition temperatures of TFE-CTFE copolymers vary in a nonlinear fashion in the range defined by the homopolymers conforming best to the Johnston equation; the behavior in the TFE-BTFE system is more linear. Whereas TFE-BTFE copolymers show a steep decrease of melting temperature at higher BTFE content, due to the amorphous character of the polymers, more regular behavior was found for TFE-CTFE copolymers. Enthalpies of fusion are also reported. The results are discussed in relation to copolymer composition and structure and are compared with data on tetrafluoroethene–hexafluoropropene (FEP) fluorocarbon resins.     

Enthalphy of mixing of bromobenzene with n-alkanes,with cyclohexane,and with benzene

A dynamic flow microcalorimeter of the Picker design was used to measure enthalpies of mixing at 298.15 K and atmospheric pressure of the six binary systems bromobenzene + n-hexane, + n-heptane, + n-nonane, + n-tetradecane, + cyclohexane, and + benzene. Within the homologous series of n-alkane systems, the interaction parameter, h₁₂, calculated from rigid-lattice group contribution theory, decreases weakly with increasing chain length of the alkane. This behavior is quite analogous to that observed with chloro-derivatives of benzene + n-alkane.     

Reactions of amines with a dimer of hexafluoropropene and with a perfluorovinyl sulfide prepared with hexafluoropropene

Some reactions of amines with a perfluorovinylsulfide, (CF₃)₂CFSC(CF₃)CFCF(CF₃)₂, prepared from hexafluoropropene (HFP) and sulfur [1] are compared to reactions of the same amines with the thermodynamic dimer of HFP, (CF₃)₂CCFCF₂CF₃. Many new ketenimines, eneamines, amidines, nitriles, and quinoline derivatives are reported.     

Reaction of isatin with alkylating agents with acidic methylenes

The reaction of isatin (1) with different alkyl halides 2 and alkaline carbonates in aprotic polar solvents leads mainly to N-alkyl derivatives 3. The use of alkylating agents that have acidic methylenes leads to competitive formation of the corresponding epoxide 5. The formation of 5 is favored by low-polarity solvents at low temperatures and strong bases. Epoxides 5c, d obtained using NaEtOH/EtOH at 0–5 °C are transformed into the corresponding 4-quinolinones 6 at higher temperatures. The use of Ag₂CO₃ allows obtaining compounds 3 as major products, along with varying amounts of labile O-alkyl derivatives 4 and dimerization products.     

High-temperature reactions of trichloroethylene with toluene and with methanol

Conclusions The reactions of trichloroethylene with toluene and with methanol, conducted 560–570°, leads to the formation of a mixture of the isomers R-CH=CCl₂ and cis- and trans-R-CCl=CHCl (R=CH₂C₆H₅ and CH₂OH).Translated from Izvestiya Akademii Nauk SSSR. Seriya Khimicheskaya, No. 12, pp. 2777–2778, December, 1967.We thank E. D. Lubuzh and A. V. Kessenikh for determining and interpreting the IR and NMR spectra.     

Treatment of Wool with Laccase and Dyeing with Madder

This research has explored the effect of laccase (Denilite ІІ S) on the physical properties of the wool fabric and confirms the anti-felting of wool. In the experiment, laccase was applied to a wool fabric and different characteristics including weight loss, strength, alkali solubility, felting shrinkage, water drop absorption, and dye ability with madder were studied. The surface morphology of the wool fabrics was also observed by scanning electron microscope. The results indicated that the wool fabric treated with laccase has a higher water drop absorption, lower felting shrinkage, and lower values of a ^* and b ^*. Treatment of a wool fabric with 10% or lower percentage of laccase reduced the fabric weight but increased the tensile strength. However, using higher concentration of laccase reduced fabric weight and tensile strength. The dyeing of laccase pre-treated wool fabric with madder indicated a lower lightness.