共查询到20条相似文献,搜索用时 78 毫秒
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5,10,15,20-四(3-溴-4-磺酸苯基)卟啉光度法测定痕量锌的研究 总被引:1,自引:0,他引:1
本文研究了新水溶性卟啉试剂5,10,15,20-四(3-溴-4-磺酸苯基)卟啉[T(3-BrP)PS4]与锌的显色反应。在pH4,锌与5,10,15,20-四(3-溴-4-磺酸苯基)卟啉形成稳定的1:1配合物,其最大吸收波长位于422.0nm,摩尔吸光系数为3.9×105L·mol(-1)·cm(-1)。锌量在0~2.5μg/25mL范围符合比尔定律。方法具有较高的灵敏度和较好的选择性,用于人发和大米中痕量锌的测定,结果与原子吸收法一致。 相似文献
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本文研究了新水溶性卟啉试剂5,10,15,20-四(3-溴-4-磺酸苯基)卟啉[T(3-BrP)PS_4与铜的显色反应。在pH3,铜与5,10,15,20-四(3-溴-4-磺酸苯基)卟啉形成1:1的稳定配合物。此配合物的最大吸收波长位于412.8nm,摩尔吸光系数为2.61×10 ̄5L·mol ̄(-1)·cm ̄(-1)。铜量在0~3.0μg/25mL范围内符合比尔定律,工作曲线回归方程为y=0.00943、+0.167x,相关系数为r=0.9997。方法有较高的灵敏度和较好的选择性,直接用于大米和茶叶中痕量铜的测定,结果与AAS法一致。 相似文献
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溴化十六烷基三甲胺存在下,9—(3,5—二溴)水杨基荧光酮与锡的显色反研究及 总被引:8,自引:1,他引:7
本文研究了在溴化十六烷基三甲胺存在下,9-(3,5-二溴)水杨基荧光酮与锡的显色反应。实验表明:该显色反应灵敏度高,选择性好,稳定时间长。用于水和矿石中锡的测定,结果符合分析要求。 相似文献
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本文研究新试剂10-(2-羧基苯偶氮)-9-菲酚(简称CAP)的合成,测定试剂的离解常数。研究了试剂CAP与铈(Ⅳ)的显色反应。在表面活性剂OP存在下,光度法测定球墨铸铁中铈的含量,结果较满意。 相似文献
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气相色谱与原子吸收联用及其在有机锡化合物形态分析中的应用 总被引:11,自引:0,他引:11
本文研究适合于有机锡化合物形态分析的气色谱-原子吸收联用技术的接口。在优化、改进的分离测定条件下,成功地实现了一甲基锡、二甲基锡、三甲基锡、一丁基锡、二丁基锡、三丁基锡、四丁基锡化合物的分离,并以内标法测定了湖、海水、工业废水等水样中的丁基锡化合物。 相似文献
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New and efficient synthesis of solid-supported organotin reagents and their use in organic synthesis
Alejandro G. Hernán 《Journal of organometallic chemistry》2006,691(8):1466-1475
Novel resin-bound organotin reagents have been prepared, including for the first time resin-bound dimethyl tin reagents. Mild methodology has also been developed for the very efficient synthesis of resin-bound distannanes. The resin-bound tin chloride reagents have been used in a catalytic Stille coupling cycle and the resin-bound distannanes have been used in atom transfer cyclisations and proved to be much more effective than previously described resin-bound distannanes. As expected the use of resin-bound tin reagents facilitated their easy removal at the end of the reaction, and consequently residual tin levels in the organic products were low or negligible. The resin-bound distannanes could not, however, be successfully used for the palladium catalysed stannylation of a simple aryl iodide, which would have provided a useful approach to radiolabeling of aromatic substrates. The reasons for the failure in the stannylation process is unclear but crystal structure evidence indicates that there is a hypervalent interaction between the resin-bound tin atom and an adjacent ether oxygen which may effect the reactivity of the tin intermediates in the stannylation sequence. 相似文献
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Del Colle V Souza-Garcia J Tremiliosi-Filho G Herrero E Feliu JM 《Physical chemistry chemical physics : PCCP》2011,13(26):12163-12172
Ethanol oxidation on platinum stepped surfaces vicinal to the (111) pole modified by tin has been studied to determine the role of this adatom in the oxidation mechanism. Tin has been slowly deposited so that the initial stages of the deposition take place on the step, and deposition on the terrace only occurs when the step has been completely decorated. Voltammetric and chronoamperometric experiments demonstrate that tin on the step catalyzes the oxidation. The maximum enhancement is found when the step is completely decorated by tin. FTIR experiments using normal and isotopically labeled ethanol have been used to elucidate the effect of the tin adatoms in the mechanism. The obtained results indicate that the role of tin is double: (i) when the surface has sites capable of breaking the C-C bond of the molecule, that is, when the step sites are not completely covered by tin, it promotes the oxidation of CO formed from the molecular fragments to CO(2) through a bifunctional mechanism and (ii) it catalyzes the oxidation of ethanol to acetic acid. 相似文献
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《液相色谱法及相关技术杂志》2012,35(6):1159-1172
Abstract Some new samples of tin(IV)-iodophosphate have been synthesized and their ion exchange properties have been studied. Adsorption behaviour of different metal ions on tin(IV)-iodophosphate (TIP5), in H+ form, in different solvent systems have been examined. Kd values of few metal ions, in 4M DMSO medium, have also been determined on the same ion-exchanger in NH+ 4 form. Effect of particle size of tin(IV)-iodophosphate (TIP5), in H+ form, on the Kd values of metal ions has been studied. Separations of a number of metal ions have been achieved on tin(IV)-iodophosphate (TIP5) columns. 相似文献
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本文提出了一种填补国内空白的新产品-气体分析用锡片和锡囊的研制方法。对锡片,锡囊的外观和内在质量检测结果证明,研制的锡片,锡囊完全达到了美国LECO公司同类产吕的技术标准,而价格只有进口产品的四分之一左右。应用结果表明,该产品完全可以取代进口,完全适用于用事种金属及其俣金材料中气体分析的要求。 相似文献
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A differential pulse polarographic procedure for the determination of 0.001-0.02% of tin in zinc-aluminium alloys is described. The tin is first separated from interfering elements such as copper and lead by homogeneous co-precipitation with aluminium succinate. The tin is determined polarographically in a 1M hydrochloric acid + 4M ammonium chloride electrolyte. After the tin has been masked with alkaline citrate a second polarogram is recorded to ascertain whether residual lead is present and, if so, a correction is applied. 相似文献
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The direct synthesis of the two industrially important organotin intermediates, di(n-butyl)tin and di(n-octyl)tin dihalides, has been investigated by reacting the appropriate alkyl halide with metallic tin undervarying conditions. Observations were made on the influences of temperature, pressure, reaction time, nature of the tin metal, organic halide/tin reactant ratios and the presence of catalysts on the extent of tin conversion and yields of the organotin products. The efficacy of the onium halides, notably n-Bu4NI, Me3SI and Ph3MeAsI, either singly or in binary combinations with iodine or inorganic iodine compounds, in catalysing the synthesis of the above dialkyltins as well as higher di(n-alkyl)tin analogues is described. 相似文献
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Khalameida S. Sydorchuk V. Levytska S. Shcherban N. 《Journal of Thermal Analysis and Calorimetry》2020,140(5):2131-2142
Journal of Thermal Analysis and Calorimetry - The samples containing 1–10% tin dioxide supported onto silica gel have been synthesized via precipitation or thermolysis of tin tetrachloride.... 相似文献
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《液相色谱法及相关技术杂志》2012,35(4):777-794
Abstract Iodates and iodophosphates of tin(IV), zirconium(IV) and iron(III) have been synthesized under varying conditions and studied their ion exchange behaviour. Among the various ion exchangers synthesized, tin(IV)-iodophosphate is chosen for detailed study owing to its highest ion exchange capacity and highest chemical stability. The most stable sample is prepared by mixing 0.1M stannic chloride, 0.1M potassium iodate and 0.1M potassium dihydrogen orthophosphate solutions in the volume ratio 1:1:2 respectively at pH 0–1. It is a monofunctional weak cation exchanger. Its ion exchange capacity for K+ is 1.6 meq/dry g. The thermal and chemical stabilities of this material have been determined and compared with Zr(IV)-phosphoiodate. Effect of heating on the properties of tin(IV)-iodophosphate has been determined. To explore the separation potential of tin(IV)-iodophosphate Kd values of different metal ions have been determined in organic solvents. A number of important separations of metal ions of industrial utility have been successfully achieved on the columns of tin(IV)-iodophosphate. 相似文献