Spectrophotometric Study of 1, 3-Cyclohexanedione Bisthiosemicarbazone Monohydrochloride -Bi (III) Complex. Determination of Bi (III)

Abstract

The spectrophotometric study was made of red-violet 1, 3-cyclohexanedione bis-thiosemicarbazone-Bi (III) in an acidic dimethylformamide-water solution (λ_max = 540 nm, ? = 3.3 × 10^?4 1. mol^?1. cm^?1, stoichiometry 3:1, apparent stability constant (6.0 × 10¹⁰). A new method for the spectrophotometric determination of Bi (III) is proposed for concentrations between 0.7 and 7.4 ppm. The relative error (95 % confidence level) is 0.5 % for 3.7 ppm of Bi (III).

The extraction with methyl isobutyl ketone of the red-violet complex was also studied spectrophotometrically (λ_max = 550 nm, ? = 3.34 × 10⁴ 1. mol^?1.cm^?1, stoichiometry 2:1). A new method for the extraction-spectrophotometric determination of Bi (III) is proposed for concentrations, in aqueous phase, between 0.2 and 1.2 ppm. The relative error (95 % confidence level) is 0.8 % for 0.9 ppm of Bi (III).     

The Simultaneous Spectrophotometric Determination of Osmium and Ruthenium

Abstract

A spectrophotometric procedure is described for the simultaneous determination of osmium and ruthenium in the form of bromo complexes. It was found that a blue ruthenium-thiourea complex could be formed in 6.7 M HBr solutions while the osmium could be maintained as the hexabromoosmate complex. Absorption maxima were at 620 μ for the ruthenium complex and at 446 μ for the osmium complex. Molar absorptivities for the ruthenium complex were 2.47 × 10³ at 620 μ and 763 at 446 μ. For the osmium complex molar absorptivities were 328 at 620 μ and 6.81 × 10³ at 446 μ. The method is useable over the range of 5 to 30 ppm with an absolute error of = 1 ppm over the range. Other platinum metals interfere.     

模糊聚类-偏最小二乘光度法同时测定锇和钌

将模糊聚类分析与偏最小二乘相结合，对锇、钌双组份重叠光谱进行解析；较好地解决了校正分析中校准模型的优化问题，提高了分析结果的准确度；研究了锇、钌－ＳｎＣｌ２－乳化剂ＯＰ－阿拉伯树胶（ＡＧ）－丁基罗丹明Ｂ（ＢＲＢ）高灵敏多元离子缔合物显色体系。锇、钌的检出限分别为 ０，６３２ μｇ／Ｌ和 ０．３６８ μｇ／Ｌ，模拟地质样品分析结果的相对误差小于±１０％。     

催化动力学分光光度法测定痕量锇

在磷酸介质及加热条件下 ,锇 对KBrO3氧化二氨替比林基 对二甲氨基苯基甲烷 (DAMAM)显色反应有强烈的催化作用 ,由此建立了测定痕量锇的催化动力学分光光度分析法。体系催化反应 (吸光度为A)和非催化反应 (吸光度为A0 )的最大吸收波长均为 5 4 0nm ,锇含量在 0～ 14 μg L范围内与 (A -A0 )呈线性关系 ,检出限为 1.82× 10 - 9g mL ,方法用于冶金产品和贵金属精矿中痕量锇的测定 ,结果满意     

Determination of Platinum Metals III. An Extraction Spectrophotometaic Determination of Tetravalent Osmium

Abstract

A new spectrophotometry determination of Os(IV) has been developed, based on the formation of the [OsCl₆]^2? - 1-carb-ethoxypentadecyltrimethylammonium cation ion-associate extract-able into chloroform. The measurement is carried out at 340 or 376 nm. It is possible to determine 1.5 to 18.6 μg Os in 1 ml of the chloroform phase.     

赤霉素的快速分光光度测定法的研究

本文对赤霉素的测定提出了一种利用福林反应的快速分光光度法。由于选用适当的测量波长以消除试样溶液中杂质对吸光度的影响和采用快速提取剂以加速试样溶液的制备过程,并研究了测定中的各个环节,使操作手续简化,大大提高了分析速度,增进了测定精度。用本法所得结果与通用的荧光法相符。     

稳健偏最小二乘光度法同时测定贵金属元素锇和钌

本文将稳健偏最小二乘法用于贵金属元素锇、钌的光度法同时测定，较好地解决了实际校准模型由于实验误差偏离正态分布使计算结果的精度遭到破坏的问题。     

显色剂N-间甲苯基-N''''-(氨基对苯磺酸钠)硫脲光度法测定微量铂(Ⅳ)

研究了新试剂－Ｎ间甲苯基－Ｎ’－（氨基对苯磺酸钠）硫脲（ＭＭＰＴ）与铂（Ⅳ）的显色反应，结果表明，在 ｐＨ ３．７～４．４的 ＨＡｃ－ＮａＡｃ缓冲体系中，Ｐｔ（Ⅳ）与 ＭＭＰＴ形成 １：３的绿色水溶性络合物，最大吸收波长位于 ７５４．４ ｎｍ，表观摩尔吸光系数ε７５４．４＝８．５８ × １０４·ｍｏｌ－１·ｃｍ－１，铂含量在０～１．２８ ｍｇ／Ｌ的范围内服从比尔定律。本法灵敏度高、选择性好、操作简便、测定结果准确可靠。将其用于矿石和催化剂中铂的测定，结果令人满意。     

在PVA存在下Os-SnCl_2-亮绿离子缔合体系的研究高纯镍中微量Os的测定

本文研究了Os-SnCl_2-PVA-亮绿离子缔合体系的显色反应,摩尔吸光系数ε_(434)为5.6×10~6L·mol~(-1)·cm~(-1),锇含量在0.1～0.7μg/25mL范围内遵守比耳定律,室温下显色后,吸光度在110min内稳定。研究了30种外来离子的影响,并进行了高纯镍中微量锇的测定。     

钯、铑和铂的同时分光光度测定

贵金属混合物光度分析常需分离,同时测定的报导亦少见。本文提出了一种不用分离,不用萃取,不用解联立方程,灵敏、简便同时分光光度测定三种贵金属的方法。     

化学计量学-动力学分光光度法同时测定两种糖皮质类激素

在碱性介质中,高锰酸钾能将糖皮质类激素(醋酸泼尼松和地塞米松)氧化,而本身被还原成绿色的锰酸钾,基于这一反应,本文提出了同时测定醋酸泼尼松和地塞米松的化学计量学-动力学分光光度法.研究发现反应体系在610 nm处有一个吸收峰,实验以该波长为检测波长,优化实验条件.在该条件下,检测醋酸泼尼松和地塞米松的线性范围分别为0....     

Spectrophotometric Method for the Rapid Determination of Microgram Amounts of Ethionamide

Abstract

Spectrophotometric Method for the Rapid Determination of Microgram Amounts of Ethionamide

A simple and sensitive method for the determination of microgram amounts of ethionamide is described. Ethionamide is converted to corresponding 2-ethyl-γ-pyridyl thiohydroxamic acid which gives a purple violet colour (Λmax 510 nm) with ferric chloride in acidic medium. This forms the basis for the quantitative determination of ethionamide in its pure form and in tablet form. The influence of substrates, commonly employed as excipients, is studied. An attempt has been made to determine ethionamide in the presence of other antitubercular drugs.     

Simultaneous Determination of Micro Bromide and Iodide by Kinetic Spectrophotometric Method

ABSTRACT

ABSTRACTA new kinetic spectrophotometric method for the simultaneous determination of concentrations of micro bromide and iodide has been proposed. It is based on their catalytic effects on the reaction of m-cresol purple oxidized by potassium periodate in hydrochloride acid medium. The reaction rate was monitored by measuring the decrease in absorbance at 528nm and the increase in absorbance at 455nm. The total difference in absorbance of the sum of bromide and iodide is identical with determination of bromide was carried out after Cr(VI) oxidized I? to I₂, and I₂ was removed by extraction with CCI₄, and the amount of iodide was measured by subtracting the absorbance change of bromide from the total absorbance change in the presence of bromine and iodide. The optimum conditions influencing the reaction rate were studied. The linear range of determination is 0～4.0μg/ml for Br? and 0～3.0 μg/ml for I?. The detection limits are 0.032μg/ml for Br? and 0.059 μ/ml for I?. The method was successfully applied to the determination of micro amounts of bromide and iodide in food and life samples.     

Simultaneous Spectrophotometric Determination of Cadmium, Zinc and Copper with Kalman Filter

The compound 2-QADNm can form red complexes with caamium(II), zinc(II) and copper(II). The simultaneous determination of cadmium, zinc and copper with Kalman Filter is described in this paper, the proposed method was applied to a two-component system for determining cadmium and copper,and a three-component system for determining cadmium, zinc and copper.     

Simultaneous Spectrophotometric Determination of Sulfamethoxazole and Trimethoprim in Drugs.

Abstract

Two methods, namely first derivative and classical least squares methods are selected and applied for comparative purposes to analyze uv-spectra of the methanolic solutions of the cited components in synthetic binary mixtures and in a number of antibacterial pharmaceutical preparations, viz. three tablets and two syrups produced by Egyptian companies. The former technique is based on measuring the absorbances at zero-crossing wavelengths, 288 and 240 nm for the two drugs, respectively. Calibration curves are rectilinear in the range 4 –20 μg/ml of both components. The latter method is based on a pure standard full-spectra treatment ranged from 350 to 200 nm at 2 nm intervals to compute the concentration of unknowns. A statistical analysis of the results is reported.     

Extraction,Spectrophotometric, and Atomic Absorption Spectrophotometric Determination of Selenium With N-Phenylbenzohydroxamic Acid

Abstract

Solvent extraction spectrophotometric and atomic absorption spectrophotometric methods for the determination of selenium(IV) in microgram quantities are described. The selenium(IV) forms yellow colored complex with N-phenylbenzohydroxamic acid (PBHA) extractable into chloroform from 7 M HClO₄. Se-PBHA complex has maximum absorbance at 345 nm with a molar absorptivity 1.5 × 10⁵ 1 mol^?1 cm^?1 and Sandell's sensitivity 0.000526 μg /cm². Effect of molarity, reagent concentration, diverse ions on the extraction of selenium complex were studied. The selenium is determined in presence of tellurium.     

Spectrophotometric Determination Of Rifampin in the Presence of its Degradation Products in Pharmaceutical Preparations

Abstract

The determination of rifampin in the presence of its main degradation products, 3-formyl rifampin and rifampin quinone using two spectrophotometric methods is described. Both Glenn's method and first derivative spectrophotometry were successfully adopted. No preliminary separation steps were required in either cases. Both methods gave accurate and reproducible results for the determination of the drug in dosage forms. The percentage recoveries ranged from 99.33% ±0.63 to 100.2% ± 0.44. The proposed methods are more simple, rapid than other existing methods and can be readily adopted in control laboratory.     

锇(Ⅳ)催化抗坏血酸还原三溴偶氮胂的褪色反应特性及痕量锇的测定

研究了在盐酸介质中,在活化剂磷酸存在下,Os(Ⅳ)催化抗坏血酸还原三溴偶氮胂的褪色反应特性;测定了反应级数和表观活化能;拟定了反应的最佳条件,建立了测定痕量锇的新方法.在85±0.05℃水浴中加热8 min,测定的检出限为3.65×10-8 g/L,线性范围为0～4.0 μg/L,相对标准偏差为2.8%～2.9%.用于合金和催化剂样品中锇的测定,结果满意.     

Spectrophotometric Determination of Methotrexate and in Pharmaceutical Formulations

Abstract

Methotrexate, 4-amino-10-methyl folic acid, is one of the drugs belonging to the folic acid antagonists that is widely used for the treatment of cancer and psoriasis ^{1, 2}