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1.
研究了显色剂2-(2-噻唑偶氮)-5-[(N,N-二羧甲基)氨基]苯磺酸(简称TADCABS)与金(II)的显色反应.结果表明,在0.3mol/LH3PO4介质中,TADCABS与金形成稳定的深红色的3∶1配合物,其最大吸收波长575nm,金浓度在0~50μg/25mL范围内符合比耳定律,表观摩尔吸光系数ε575为1.45×104L·mol-1·cm-1,方法用于测定阳极泥及含硫金矿中微量金,结果满意  相似文献   

2.
报道了一种对钯离子具有高灵敏度和选择性的新试剂2-(2-噻唑偶氮)-5-[(N,N-二羧基甲基)氨基]苯甲酸(TADCAB)。在0.5mol/LHNO_3介质中,TADCAB与Pd(Ⅱ)形成蓝色配合物,组成为Pd:TADCAB=1:2,最大吸收波长652nm。钯浓度在0~1.4μg/mL范围内符合比耳定律。用双波长法测定,表观摩尔吸光系数ε_(652.0~533.6)=8.2×10 ̄4L·mol ̄(-1)·cm ̄(-1),可以允许大量金属离子共存。所确立的方法无需掩蔽剂和其它分离手段,即可直接用于Pt-Pd催化剂中微量钯的测定,结果满意。  相似文献   

3.
用1300-Ⅱ型吸附树脂吸附噻唑偶氮类试剂制取浸渍树脂。研究了树脂对试剂和对金的吸附率及其与溶液pH值的关系,求得浸渍树脂吸附金的平衡速率和吸附容量,并在条件试验基础上拟订了柱操作分离富集微量金的方法,获得了满意的结果。  相似文献   

4.
本文研究了BTAEB作为络合滴定铜的指示剂的分析性能。结果表明,在pH4.0~6.5范围内,目视滴定0.3~500mg铜,终点由蓝色变为紫红色,变色敏锐,准确度高。应用于锡磷青铜和深井泵叶轮合金中铜的分析,结果个人满意。  相似文献   

5.
研究了2-(3,5-二氯-2-吡啶偶氮)-5-二甲氨基苯胺与铂(Ⅳ)的显色反应,在pH3.5~6.0醋酸-醋酸钠介质中,沸水浴加热25min,试剂与铂(Ⅳ)形成1:4的紫色配合物,再提高酸度至2.9~4.0mol/L盐酸溶液,其最大吸收峰红移至630nm,灵敏度显著提高,表现摩尔吸光系数ε_(600)=7.0×10 ̄4L·mol ̄(-1)·cm ̄(-1),铂含量在0~32μg/25mL范围内符合比耳定律。大多数常见金属离子不干扰测定,所拟方法操作简便,用于催化剂中微量铂的测定,结果满意  相似文献   

6.
本文研究了新显色剂2-(5-溴-2-吡啶偶氮)-5-二甲氨基苯胺与镍(Ⅱ)的反应条件。试验结果发现,在阴离子表面活性剂十二烷基硫酸钠存在下,在pH5.2~6.5范围内,试剂与镍(Ⅱ)形成稳定的2∶1配合物。其最大吸收波长在570nm处,表观摩尔吸光系数为1.24×10 ̄5L·mol ̄(-1)·cm ̄(-1)。镍(Ⅱ)浓度在0~0.4μg·mL ̄(-1)之间符合比尔定律。以硫脲和氟化按作掩蔽剂,可消除Cu ̄(2+)、Pd ̄(2+)、Fe ̄(3+)等离子的干扰。所拟方法用于铝合金中微量镍的测定,结果满意。  相似文献   

7.
张小玲  张光 《分析化学》1994,22(1):61-63
本研究了4-(2-噻唑偶氮)-2,4-二氨基甲苯(简称TADAT)与铑的显色反应。在pH=3.7~4.9的酸度范围内试剂与铑形成红色络合物,加入无机酸后色泽加深,络合物的最大吸收位于590nm,表观摩尔吸光系数为1.1×10^5L·mol^-1·cm^-1,其组成为Rh:TADAT=1:3。铑浓度在0~12μg/25ml范围内服从比尔定律。该方法用于模拟样中铑的测定,结果满意。  相似文献   

8.
钒是具有重要用途的元素 ,其测定受到重视。二安替比林甲烷类[1]及杂环偶氮苯酚类显色剂[2 ,3]测定钒灵敏度和选择性较高 ,变色酸偶氮类显色剂[4 6 ]的应用也曾有报道 ,而杂环偶氮苯甲酸类显色剂研究较少[7,8]。本文研究了钒 (Ⅴ )与 2 (2 噻唑偶氮 ) 5 二甲氨基苯甲酸 (TAMB)的显色反应 ,结果表明 ,在 pH 3 .5 3 .8甲酸 NaOH缓冲介质中 ,钒(Ⅴ )与TAMB反应生成一种稳定的可溶于水的蓝色配合物。1 试验部分1.1 仪器与试剂72 1型分光光度计pHS 2型酸度计钒 (Ⅴ )标准溶液 :用偏钒酸铵 (NH4 VO3)水溶后配成含钒 1…  相似文献   

9.
用新合成的偶氮试剂2-(5-硝基-2-吡啶偶氮)-5-二甲氨基苯胺(5-NO_2-PADMA)研究了光度法测定他的反应条件。结果表明,在0.45~1.2mol/L盐酸介质中,钯与试剂形成稳定的蓝色配合物,其最大吸收波长位于621nm处,表观摩尔吸收系数为9.4×10 ̄4L·mol ̄(-1)·cm ̄(-1),配合成的组成为Pd:5-NO_2-PADMA=1:2,钯浓度在0~10μg/10mL范围内符合比尔定律。本方法是目前测定钯的高灵敏度和高选择性体系之一。用于含钯分子筛及二次合金管理样-88中微量钯的测定,结果满意。  相似文献   

10.
11.
近年来,杂环偶氮苯甲酸类显色剂取得了较快的发展。由于氨基取代结构对试剂性能有较大的影响[1],因此本文合成了新显色剂2-(2-噻唑偶氮)-5-二乙氨基苯甲酸,(TAEB)并研究了它与钴的显色反应。  相似文献   

12.
 A simple, rapid, selective, sensitive and economical method has been developed for the simultaneous determination of trace amounts of palladium and nickel in aqueous methanolic medium using 2-(2-thiazolylazo)-5-dimethylam inobenzoic acid as an analytical reagent by first derivative spectrophotometr y. Palladium is determined by measuring base to peak distance at λ=695.0 nm while nickel is estimated by zero crossing method in the mixture. The linearity is maintained between 0.12–1.75 μg mL−1 for palladium and 0.07–1.60 μg mL−1 for nickel in the pH range 2.8–7.2 and 3.4–8.8 respectively. Seven replicate determinations of 1.0 μ g mL−1 of palladium and 0.8 μg mL−1 of nickel in a mixture give a mean signal height of 0.391 for Pd and 0.541 for Ni with relative standard deviations of 0.9% and 1.2%, respectively. The sensitivity of the proposed method is 0.391 (dA/dλ)/(μg mL−1) for palladium and 0.685 (dA/dλ)/(μg mL−1) for nickel. Various parameters have been optimised for the simultaneous determination of palladium and nickel in various complex samples. Received March 30, 1999. Revision November 25, 1999.  相似文献   

13.
A new water soluble chromogenic reagent, 2-(5-bromo-pyridylazo)-5-[(N,N-dicarboxylmethyl)amino]-phenol has been synthesized. Its colour reaction with various metal ions was tested, and the acid dissociation constant of the reagent, and the stability constants of the chelates of Ni2+, Co2+, Cu2+, Mn2+, Pb2+, Zn2+ and UO 2 2+ were determined. The application of the reagent to spectrophotometric determination of nickel in irons is presented.  相似文献   

14.
《Analytical letters》2012,45(9):1675-1684
Abstract

The reaction between lead(II) and 2-(2-Thiazolylazo)-p-Cresol(TAC) in the presence of TERGITOL NPX (4 mg/ml) at an apparent pH 9.0–10.0 results in an intensely colored complex which is stable for at least 4 hr.

The composition of the complex is 1:2 cation: TAC and the log of the formation constant is 11.92 ± 0. 40. Beer's law is obeyed up to 6.0μg.ml?1 of lead(II) at 650nm.

The apparent molar absorptivity at 650 nm is 2.07 × 104 1. mole?1.cm?1 and the detection limit was obtained as 10.0 ng.ml?1 of lead(II).

The method is applied to determination of lead(II) in copper-base alloy.  相似文献   

15.
16.
本文报道了新试剂2-(4-苯基-2-噻唑偶氮)-5-[(N,N-二羧基甲基)氨基]苯甲酸的合成及其与金属离子的显色反应。详细讨论该试剂与钯显色反应的最适条件,在酸性条件下,试剂与钯形成2:1蓝色络合物,其稳定常数K_稳=5.39×1O ̄(11),采用双波长法测定,络合物的摩尔吸光系数ε_(676.4-486.0)=5.61×10 ̄4L·mol ̄(-1)·cm ̄(-1),比单波长测定的灵敏度(ε_(676.4=3.58×10 ̄4)提高了57%。试剂的灵敏度高,选择性好,可直接用于铂-钯催化剂中微量他的测定,结果满意。  相似文献   

17.
本文合成了新显色剂2-[2-噻唑偶氮]-5-二乙氨基苯甲酸(TAEB),研究了它与铑的显色反应。结果发现,在pH4.0~6.5的缓冲溶液中,铑(Ⅱ)与TAEB形成一种绿色络合物。其最大吸收波长为674nm,表现摩尔吸光系数为1.44×10~5L·mol~(-1)cm~(-1)。铑含量在0~20μg/25ml范围内服从比尔定律。络合物中铑(Ⅱ)与TAEB的摩尔比为1:1。该方法灵敏度高、选择性好。常见的阴、阳离子不干扰,镍(Ⅰ)、钴(Ⅰ)和铜(Ⅰ)的干扰可用EDTA来消除,用于催化剂中微量铑的测定。结果令人满意。  相似文献   

18.
Since 8-aminoquinoline has (N,N) as its chelating atom,it is more selective than 8-hydroxyquinoline and 8-mercaptoquinoline. So recently, derivative of 8-aminoquinoline has attracted much attention as analytical reagent. In this work, a new type of 8-aminoquinoline derivative 5-(6-nitro-2-benzothiazoleazo)-8-aminoquinoline (NBTAQ) has been synthesized and tested as a possible chromogenic reagent for the spectrophotometric determination of cobalt and nickel. The result shows that in the presence of the cationic surfactant cetyltrimethylammonium bromide (CTAB) and borax buffer solution, cobalt and nickel react with the reagent to form 1:2 blue complexes, respectively. The absorption peaks of Co-NBTAQ and Ni-NBTAQ complexes were located at 650 and 615 nm, respectively, and the apparent molar absorbtivities are 9.21×l04(Co) and 1.13×l05 (Ni) I.mol-1.cm-1. The methods adhere to Beer's law for 0-0.32 μg. Ml-1 of cobalt and 0-0.24 μg. Ml-1 of nickel and the colour system is stable for no less than 24 h. The experimental variables affecting colour formation and the possible interference of co-existing ions were thoroughly studied. The optimum conditions established were incorporated in the recommended procedures.  相似文献   

19.
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