Direct and Derivative Spectrophotometric Determination of Zinc with 2,4-Dihydroxybenzaldehyde Isonicotinoyl Hydrazone in Potable Water and Pharmaceutical Samples

A simple and sensitive spectrophotometric method is developed for the determination of zinc in aqueous solutions. The metal ion forms a greenish-yellow colored complex with 2,4-dihydroxybenzaldehyde isonicotinoyl hydrazone (2,4-DHBINH) in the pH range of 4–10. The complex shows maximum absorbance at 390 nm and in the pH range of 6–8. Beer's law is obeyed in the range 0.10–1.50 μg/mL of Zn(II). The molar absorptivity and Sandell's sensitivity are 3.55 × 10⁴ mol⁻¹ cm⁻¹ and 0.0016 μg/cm², respectively. The composition of the complex is 1 : 1. The effect of interfering ions has been studied, and the method was applied to the determination of zinc(II) in potable water and pharmaceutical samples. A fast derivative spectrophotometry method is also proposed for the determination of zinc in the range 0.06–1.60 μg/mL, which is more sensitive than the zero order method. __________ Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 9, 2005, pp. 933–937. Original Russian Text Copyright ? 2005 by Sivaramaiah, Raveendra Reddy. The text was submitted by the authors in English.     

耐尔蓝-钍钼杂多酸光度法测定钍

本文研究超高灵敏光度法测定钍。在聚乙烯醇（PVA）存在下，耐尔蓝（NB）与钍钼杂多酸络阴离子形成离子缔合物。在1．2mol／L高氯酸介质中缔合物的最大吸收位于590nm，摩尔吸光系数ε值4．45×106L·mol－1·cm－1，钍量在0～28μg／L范围服从比耳定律；测定极限C（Th）3．4μg／L（n＝9）；对20μg／LTh分析9次的相对标准偏差1．5％；缔合物的摩尔组成Th：Mo：NB＝1：12：3。考察了50多种共存离子影响，允许100倍量Ce（Ⅲ）、50倍量U（Ⅵ）和等量Ti（Ⅳ）存在。本法用于地质样品中钍的测定，结果满意。     

萃取光度法测定钨精矿中钍

试样经碱熔、溶液浸取后 ,以 Mg Cl2 为载体沉淀钍 ,再经沉淀溶解、萃取和反萃 ,在 3.6mol/L 盐酸介质中对钍进行光度法测定。钍量在 0～ 2 0 μg/2 5m L浓度范围符合比耳定律。钨精矿中常见杂质元素及其含量对钍的测定无明显影响。方法的标准偏差为 5.0× 1 0 -5～ 1 .1 7× 1 0 -4 ,相对标准偏差为 1 .87%～1 0 .8%。     

Determination of Some Quinone Containing Drugs by Direct and Titrimetric First Derivative Spectrophotometric Methods

Abstract

The first-derivative spectra of some metal complexes of danthron and phanquone show well defined, prominent peaks. This can be made the basis of a spectrophotometric technique for the determination of both danthron and phanquone.

Two spectrophotometric. procedures are described. The first-derivative spectrophotometric technique, found to be more sensitive than the direct-absorbance method when the metal complex is weakly absorbing, can be applied to the determination of danthron, and phanquone both in pure form and in pharmaceutical formulations. Danthron can be determined in the range of 0.48–5.7 mg using metal complexes. Phanquone can be determined in the range of 0.42–2.08 mg using iron (II), and 3.78–11.34 mg using cobalt (II).

The second procedure is a first-derivative spectrophotometry titration for the determination of 0.096–0.57 mg of danthron and 0.048–1.0 mg of phanquone using the standard metal ion- solutions as titrants.     

Spectrophotometric and First Derivative Spectrophotometric Determination of Magnesium with 1-Hydroxy-2-Carboxyanthraquinone

Abstract

1-Hydroxy-2-carboxyanthraquinone reacts with magnesium in ethanol-water mixtures to form a red complex having an absorption maximum at 490 nm in alkaline medium. A detailed study of the characteristics of this complex has been carried out and a spectrophotometric method for the determination of magnesium at the 0.4–4.0 μg ml^?1 level is proposed. The method has been sensitized by employing first derivative spectrophotometry. By the use of the derivative approach magnesium can be determined between 0.08–0.40 μg ml^?1. Statistical analysis of the results is also described.     

导数分光光度法直接测定环境水中的十二烷基苯磺酸钠

用四阶导数分光光度法,无需经显色与萃取便可直接测定环境水中十二烷基苯磺酸钠的含量。本法抗干扰能力较强,检出限为0.7mg/l(即2×10~(-6)M),回收率为96～103%。     

First Derivative Spectrophotometric Determination of Phenytoin

Abstract

The first derivative curve (D₁) of absorption spectrum of Phenytoin in buffer pH 10 develos negative peaks at 244, 263 and 270 nm. D₁ at 244 nm was found linearly related to concentration over a range 0.4 ? 1.4 mg per 100 ml and highly reproducible (C.V. %=0.62). Tablets and capsules have been analyzed using D₁ at 244 nm and the mean percentage found were 99.7 ± 0.81 and 103.3 ± 0.44, respectively. The B.P. method gave 100.9 and 103.8 %, respectively.     

钕-依诺沙星-十六烷基三甲基溴化铵体系导数光度法测定钕

详细研究了钕 依诺沙星 (ENX) 十六烷基三甲基溴化铵 (CTMAB)体系的常规吸收光谱和导数吸收光谱性质 ,发现阳离子表面活性剂对Nd ENX体系吸收强度有增强作用。采用二阶导数光谱不仅消除了有关干扰 ,而且灵敏度较常规光谱法提高了 7.2倍。探讨了利用该体系以二阶导数分光光度法测定钕的最佳条件及影响因素。在最佳实验条件下 ,Nd的浓度在 1.2× 10 - 5～ 2 .7× 10 - 4mol L范围内与体系吸光度的二阶导数呈线性关系 ;检测限为 1.0 4× 10 - 5mol L(S N =2 )。利用该体系对稀土样品中的钕含量进行了测定 ,结果令人满意。     

Spectrophotometric Determination of Thorium with Disodium Salt of Arsenazo-III in Perchloric Acid

A rapid and sensitive spectrophotometric method has been developed for the determination of thorium using 0.04% Arsenazo-III in a 2M perchloric acid solution. Absorbance was measured in 1 cm cell and the complex has a sensitive absorption peak at 654 nm. The complex is formed instantly in perchloric acid and remains stable for 45 minutes with constant absorbance. Beer's law is obeyed in the range 1–60 g·g^–1 of thorium concentration with a molar absorptivity at 654 nm = 3.07·10⁵ M^–1·cm^–1 at 24±2°C. The foreign ions interference in thorium determination have been checked. The cations were tested at >60-fold excess of thorium, Mn(II), Fe(III), Co(II) and Ni(II) interfere negatively, whereas only Ce(III) has increased the absorbance. Among the anions, cyanide, phosphate, thiocyanate and acetate at 150-fold excess of thorium cause significant interference. However, thorium can bedetermined in the presence of nitrate, chloride, oxalate, tartrate, ascorbate, thiosulphate and citrate. The method has been applied on certified reference material for thorium determination after extractive separation and the result was found in good agreement with the certified value. The method has been also applied successfully to determine thorium at g·g^–1 level in local ore samples with a precision of ±0.04%.     

Selective Amperometric Determination of Thorium by Ethyl Cyanoglyoxalate Phenyl-2-Carboxylic Acid Hydrazone

Abstract

The reagent ethyl cyanoglyoxalate phenyl-2-carboxyllc acid hydrazone has been developed for the selective amperometric determination of thorium. Commonly associated ions like UO²⁺ ₂, Pe³⁺, La³⁺, Ce⁴⁺, and Zr⁴⁺ do not interfere even when present in ten fold molar excess. 23μg to 4.6mg thorium can be determined within an error of ±1.5 percent.     

Flotation‐Spectrophotometric Determination of Trace Amounts of Thorium

A simple, sensitive and reproducible flotation‐spectrophotometric method for the determination of thorium is reported. The method is based on the ion‐associate formation between thorium, xylenol orange (XO) and cethyltrimethyl ammonium bromide (CTAB) which is floated in the interface of the aqueous phase and n‐hexane by vigorous shaking. By discarding the aqueous solution and n‐hexane, the adsorbed ion‐associate (Th‐XO‐CTAB) on the wall of a separating funnel was dissolved in a small volume of ethanol solvent, and its absorbance was measured at 568 nm. The effects of different parameters such as pH, concentrations of HCl, XO, and CTAB, volume of n‐hexane, and standing and shaking time were studied. The calibration graph was linear in the concentration range of 2–200 ng mL^?1 of thorium(r = 0.9994). The limit of detection (LOD) is 1.4 ng mL^?1. The relative standard deviations (RSD) at 50 and 175 ng mL^?1 of thorium were 2.5% and 1.0% (n = 7), respectively. The method was successfully applied to the determination of thorium in gas mantel samples.     

磺基水杨酸紫外导数分光光度法测定微量铁

在不同ｐＨ下铁－磺基水杨酸形成组成比不同的配合物，其紫外吸收光谱也不同，在ｐＨ５～７的六次甲基四胺－盐酸介质中形成１：２配合物，最大吸收波长λｍａｘ２４８ｎｍ表观摩尔吸光系数ε＝２．９×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１比可见光区的灵敏度高１０倍，用三阶导数光谱法测定化学试剂中微量铁，结果与邻二氮菲法一致，相对标准偏差１．２％。     

Spectrophotometric Determination of Neomycin With 2,4-Dinitrofluorobenzene

Abstract

A spectrophotometric method is described for the determination of neomycin based on the reaction with 2,4-dinitrofluorobenzene. the best conditions for the reaction were obtained by using 0.02 M borate buffer (pH 9.0) as diluent, under ambient conditions after 50 minutes of reaction.     

Third Derivative Spectrophotometric Determination of Metomidate from Aqueous Solution

Abstract

The third derivative spectrophotometric method has been proposed for the determination of metomidate from aqueous solution. By hydrolysis of metomidate, D,L-l-(l-phenylethyl)-imidazole-5-carboxylic acid is formed. Determining the absolute value of the third derivative spectra in the “zero-crossing” point, the concentration of metomidate can be calculated directly without any interferences. The validity of the method was confirmed using synthetic mixtures. Kinetic investigation of the degradation rate of metomidate revealed that the proposed method is stability indicating.     

Synthesis and Crystal Structure of a Vanadium(V) Complex with 2-Hydroxy-1-naphthaldehyde Isonicotinoyl Hydrazone

1INTRODUCTION Coordination chemistry of vanadium is of current interest since it is found to be beneficial to various biological systems[1,2].Pentavalent vanadium is also known to inhibit the functions of phosphate metabo-lizing enzymes by forming the analogue of trigonal-bipyramidal phosphorus(V)intermediate[3,4].In previous papers,some mono-and binuclear cis-dio-xovanadium(V)complexes with tridentate ligands were reported[5～8].On the other hand,hydrazones are important polydentate lig…     

Fourth Order Derivative Spectrophotometric Determination of Lead with 1,10-Phenanthroline and Rose Bengal

Abstract

Higher order derivative techniques are mainly used in deconvoluting the overlapping absorption spectra of various analytes in their determination. The procedure utilizing higher order derivatives in molecular absorption spectrophotometry essentially are based on the formation of either binary or ternary complex formation. This paper deals with fourth order derivative spectrophotometric procedure for the determination of traces of lead based on the liquid-liquid extraction of ternary ion association complex lead with 1,10-phenanthroline and rose bengal into chloroform. The ternary ion associate is stable for over 24 hours. The developed procedure is simple, rapid, reliable and allows the determination of as low as 20 ppb of lead in sea water samples.     

动力学光度法测定痕量铅的研究

在氨水介质中，Ｐｂ＾２＋阻抑过氧化氢氧化偶氮胂Ⅰ褪色的作用，研究了动力学分光光度法测定痕量Ｐｂ＾２＋的新方法。该方法的检出限为４．４×１０＾－１１ｇ／ｍＬ Ｐｂ＾２＋，线性范围为０～１．０μｇ／２５ｍＬ Ｐｂ＾２＋，用以测定人发中的Ｐｂ＾２＋，获得了满意的结果。     

导数分光光度法测定纯蓝墨水中染料和防腐剂

国产纯蓝墨水一般用酸性墨水蓝、直接湖蓝5B两种工业染料和防腐剂苯酚配制.国家轻工业标准[1]和中国制笔协会墨水委员会1990年行业检测评比技术规则纯蓝墨水检测规则规定:用流条试验法与标准墨水对比并在606 nm波长处测定吸光度的方法检查色泽深度.