Simultaneous Determination of Copper (II) and Mercury (II) by Using a Zero-Crossing Method

Abstract

The application of a zero-crossing method to the simultaneous determination of copper (II) and mercury (II) with methylethylenediaminetetraacetic acid (MEDTA) is described. The procedure does not require equations to be solved, and it is suitable for concentrations of 0.008–0.036 mg ml^?1 of copper and 0.025–0.300 mg ml^?1 of mercury. The main interferences, both anionic and cationic, were easily eliminated. The method was applied to different aqueous matrices. It was compared with an atomic absorption spectrophotometry method (AA) and good results were obtained.     

Spectrophotometric and derivative spectrophotometric study of the reaction of palladium (II) and rhodium (III) with 5-(3,4-methoxyhydroxybenzylidene)rhodanine and cationic surfactants

Spectrophotometric and derivative spectrophotometric methods for the determination of Pd(II) and Rh(III) are proposed. Pd(II) forms with 5-(3,4-methoxyhydroxybenzylidene)rhodanine [3,4-MHBR], in the absence and presence of cetylpyridinium bromide [CPB], 14 binary and 134 ternary complexes having molar absorptivities of 5.77 × 10⁴ and 7.46 × 10⁴ M ^–1cm^–1 at 525 and 530 nm, respectively. Rh(III) forms a 14 complex with 3,4-MHBR in the presence of cetyltrimethylammonium bromide [CTAB], which gives a maximum absorbance at 445 nm with a molar absorptivity of 5.13 × 10⁴ M ^–1cm^–1. Derivative spectrophotometric methods are employed for the determination of Pd(II) and Rh(III) at ng ml^–1 levels utilizing these complexes. Under the optimum conditions the calibration lines for Pd(II) and Rh(III) determination fit the equations d⁴ A/d⁴ = 1.10 × 10⁶ [Pd] – 0.018 (r = 0.9967) and d⁴ A/d⁴ = 2.25 × 10⁶ [Rh] + 0.03 (r = 1.0426) and have detection limits of 5.6 and 1.2 ng ml^–1, respectively. The influences of experimental variables and foreign ions are studied. The methods are free of interference from most common metal ions and anions. The results of the analysis of some synthetic mixtures of Pd(II) and Rh(III) are reported.     

钯（Ⅱ）－二溴羟基苯基荧光酮－溴化十六烷基三甲铵体系分光光度法的研究

在ｐＨ６．１～６．７的磷酸盐介质中，钯（Ⅱ）与二溴羟基苯基荧光酮－溴化十六烷基三甲铵于室温下反应，生成水溶性和稳定性皆佳的紫色三元配合物，最大吸收波长为６００ｎｍ，对比度为７０ｎｍ，表现摩尔吸光系数为９．４８×１０￣４Ｌ．ｍｏｌ￣（－１）’ｃｍ￣（－１），桑德尔灵敏度为１．１２×１０￣（－３）μｇ．ｃｍ￣（－２），钯含量在０～７．０μｇ／１０ｍＬ范围内服从比尔定律。据此提出了一个灵敏、简便分光光度法测定钯的新方法，用于合成试样和贵金属合金中微量钯的测定，结果满意。     

Simultaneous First Derivative Spectrophotometric Determination of Palladium and Nickel Using 2-(2-Thiazolylazo)-5-Dimethylaminobenzoic Acid as an Analytical Reagent

 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.     

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.     

Spectrophotometric Determination of Mercury Using 2-(5-Bromo-2-pyridylazo)-5-diethylaminophenol

Abstract

Mercuric ion with 5-Br-PADAP forms a 1:2 complex at pH 8.0–10, which, with the addition of Triton X-100, has a molar absorptivity of 1.10 × 10⁵ at 565 nm. A method is described for the determination of mercury in industrial waste water and sludge.     

Determination of Osmium(VIII) and Palladium(II) in Mixtures by Derivative Spectrophotometry

Abstract

A sensitive method for the simultaneous determination of osmium(VIII) and Palladium(II) (up to 15 μ9/ml of Os and 11 μ9/ml of Pd) in mixtures, by first and second derivative spectrophotometry, using allyl thiourea as reagent, is described.

A statistical analysis of the results is reported.     

微乳液1-(2-吡啶偶氮)-2-萘酚分光光度法测定蔬菜样品中的钴

以十二烷基硫酸钠-溴代十六烷基三甲胺(SDS-CIMAB)复合微乳液为介质,对Co(Ⅱ)-1-(2-吡啶偶氮)-2-萘酚的显色反应条件进行了研究.结果表明该体系的λ_(max)=580nm,ε_(580)=3.4×10~4L·mol·cm~(-1),Co(Ⅱ)测定的线性范围为0～2.40mg/L.回收率在96%～103%之间,该法选择性好,用于蔬菜中Co(Ⅱ)含量的测定,得到了满意的结果.     

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。     

双波长分光光度法同时测定岩石矿物中的微量金和钯

本文提出以硫代米蚩酮为显色剂，用双波长分光光度法同时测定岩石矿物中的微量金和钯的方法，消除了测定金钯的相互干扰，该方法简便，快速，选择性好，用于矿石样品中金和钯的测定，结果满意。     

Spectrophotometric Determination of Palladium(II) with n-Hydroxy-N,N-Diphenylbenzamidine and 1 -(2-Pyridylazo)-2-Naphthol

A spectrophotometric method to determine palladium(II) at trace levels is based on the extraction of palladium(II) as a binary complex with N-hydroxy-N,N′-diphenylbenzamidine (HDPBA) in chloroform at pH 5.0 ± 0.2. The complex shows maximum absorbance at 400 nm with molar absorptivity 6.4 × 10³ L mol^?1 cm^?1. The sensitivity of the Pd(II)-HDPBA complex was enhanced by the addition of l-(2-pyridylazo)-2-naphthol (PAN). The green coloured complex shows maximum absorbance at 620 nm with molar absorptivity 1.58 × 10⁴ L mol^?1 cm^?1. Sandell's sensitivity and the detection limit of the method are 0.0067 μg cm^?2and 0.1 μg Pd(II) mL^?1, respectively. Most common metal ions associated with palladium metal do not interfere. The effects of various analytical parameters on the extraction of the metal are discussed.     

双波长分光光度法测定微量铜

报道了以５－（５－硝基－２－吡啶偶氮）－２－４－二氨基甲苯（５－ＮＯ２－ＰＡ－ＤＡＴ）为显色剂,应用双峰双波长光度法测定铜（Ｉ）的新方法。实验结果表明,在ｐＨ４．０￣ｐＨ６．０的乙酸－乙酸钠缓冲溶液中和盐酸羟胺和乙醇存在下,铜（Ｉ）可与试剂形成稳定的１：２红色配合物。     

用2—羟基—3—羧基—5—磺酸基苯重氮氨基偶氮苯流动注射分光光度法测定汞

研究了在乳化剂ＯＰ存在下，２－羟基－３－羧基－５－磺酸基苯重氮氨基偶氮苯（ＨＣＳＤＡＡ）－汞（Ⅱ）显色体系流动注射分光光度法。用ＰＨ１０．０－１０．５的Ｎａ２Ｂ４Ｏ７－ＮａＯＨ缓冲溶液作载流，汞（Ⅱ）与ＨＣＳＤＡＡ和乳化剂ＯＰ的混合试剂反应形成红色络合物。用于测定汞时，方法的线性范围是０．０５－１．０ｍｇ／Ｌ，检测限为０．０１６ｍｇ／Ｌ，进样频率为１００样／ｈ。直接应用于头发、自来水和废水中微量汞     

Atomic Absorption Spectrophotometric Investigation and Determination of Palladium

This work aims to achieve a determinate characterization of compound formation and to find out the resolution to overcome chemical interferences in atomic absorption spectrophotometric (AAS) determination of palladium. The effect of flame composition in producing a neutral palladium atoms was investigated. A new analytical procedure has been elaborated for the determination of palladium.     

双波长分光光度法测定微量钯的研究

本文报道以２－（３，５－二氯－２－吡啶偶氮）－５二甲氨基苯胺（简称为３，５－ｄｉＣｌ－ＰＡＤＭＡ）为显色剂，应用双峰双波长光度法测定钯的新方法及其钯配合物的质子化行为１．２ｍｏｌ／Ｌ的硫酸介质中，钯与试剂形成稳定的１：１绿蓝色配合物，其最大吸收峰为６２１ｎｍ，负峰为４３４ｎｍ，正，负峰吸光度绝对值之和与钯浓度线性相关，钯浓度在，每１０ｍＬ０～１２μｇ范围内符合比尔定律，表观摩尔吸光系数高达１．４４     

Derivative Spectrophotometric Determination of Copper and Palladium Simultaneously by Using MDTC as a Reagent

Abstract

A selective, sensitive, and economical derivative spectrophotometric method has been developed for the determination of trace amount of Cu(II) and Pd(II) with MDTC as a reagent in the presence of CTAB, a solubilizing agent. The molar absorption coefficient and analytical sensitivities of the 1:2 Cu(MDTC)₂ and Pd(MDTC)₂ complexes are 2.467×10⁴ and 2.989×10⁴ l mol^?1, respectively. The developed derivative procedure, is applied for the rapid and selective simultaneous determination of Cu(II) and Pd(II) in the range of 0.2–15 and 0.1–10 µg/ml, respectively. Complex matrices, including alloys, biological samples, pharmaceutical samples and synthetic mixtures have been successfully analyzed for trace amounts of two metal ions.     

Simultaneous spectrophotometric determination of Zinc(II) and Nickel(II) with 1-(2-pyridylazo)-2-naphthol

A new procedure for the simultaneous spectrophotometric determination of Zn(II) and Ni(II) with 1-(2-pyridylazo)-2-naphthol as chromogenic reagent has been developed. It is based on resolution of the mixed spectrum over the wavelength range 530–590 nm by applying a least-squares fitting program to standard spectra from each component. The spectra are recorded at an apparent pH of 5.0, provided by an acetate buffer in a mixed 6040 v/v 2-ethoxyethanol/water medium. The relative standard deviations for determination of 13.7 g of Ni and 31.0 g of Zn were 1.9 and 1.0%, respectively (8 replications). The method has been applied to the analysis of iron surfaces coated with a Zn-Ni alloy. The results are compared with those obtained by atomic-absorption spectrophotometry.     

Analysis of Sub-Microgram Levels of Palladium (II) in Environmental Samples by Selective Extraction and Spectrophotometric Determination with N-p-Methoxyphenyl-2-Furylacrylohydroxamic Acid and 5-(Diethylamino)-2-(2-Pyridylazo) Phenol

Abstract

Nine new hydroxamic acids in conjunction with four pyridylazo reagents were explored for extractive separation and spectrophotometric determination of palladium in environmental samples. It was found that maximum sensitivity and selectivity was achieved by employing N-p-methoxyphenyl-2-furylacrylohydroxamic acid (MFHA) and 5-(diethylamino)-2-(2-pyridylazo) phenol (DEPAP). Palladium was first selectively extracted with MFHA in isoamyl alcohol at pH 2.7-3.5 and the extract was equilibrated with a mixture of 5 M HCl and 10^{? 3} M solution of DEPAP in ethanol. The resulting intensely green ternary complex was measured at 560 nm (σ 5.1 × 10⁴ l mole^?1 cm^?1). The extraction system is suitable for enrichment of palladium over 15 times without loss in recovery and enables determination of palladium at levels as low as 10^?4 ppm (0.1 ppb). The method tolerates the presence of a large number of diverse ions normally associated with palladium, including platinum metals, and was employed for the determination of palladium in standard catalysts, biological materials, and freshwaters.     

Selective Spectrophotometric Determination of Palladium (II) With 2-(5-Bromo-2-Pyridylazo)-5-(Diethylamino)-Phenol

Abstract

A spectrophotometric study of the Pd(II) complex of a reagent 2-(5-Bromo-2-Pyridylazo)-5-(diethylamino)-Phenol (5-Br-PADAP) is presented. A violet complex is formed at pH 3.53, and shows maximal absorbance at 585 nm with molar absorptivity of 3.86 × 10⁴ 1. mol^?1 cm^?1. Beer's law is obeyed up to 50 μ of Pd(II). The method offers the advantages of simplicity, high precision, requires no extraction and is very selective, where 5.0 mg Pt(VI) and 0.3 mg Au(III) ions do not interfere.