2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚-BrO_3~--SCN-三元离子缔合物测定微量BrO_3~-的研究

本文研究了5-Br-PADAP在酸性介质中质子化,与BrO_3~-和SCN~-形成三元离子缔合物的最佳条件,其表观摩尔吸光系数ε_(540)=4.3×10~4L·mol~(-1)·cm~(-1),缔合物组成比为:5-Br-PADAP:BrO_(3-)SCN~-=1:1·1。提供了测定微量BrO_(3-)的新方法,可应用于化学试剂中微量BrO~(3-)的测定。此外,本文还探讨了反应机理。     

钯的PAR-氯化四苯鉮的萃取光度法测定

本文报道了钯与4-(2-吡啶偶氮)间苯二酚(PAR=H_2R,下同)和四苯钟离子形成离子缔合物的化学条件,经氯仿萃取后,建立了一种测定微量钯的萃取光度法。萃取的最佳pH为4.4,络合物的化学式为[(C_6H_5)_4As~+,PdClR~-],其最大吸收峰波长为532nm,表观摩尔吸光系数e_(532)=3.3×10~4L·mol~(-1)·cm~(-1),10mL萃取液中钯量在0～25μg内遵守比耳定律。方法简便,选择性好,用于催化剂中钯的测定,结果满意。     

2-(5-溴-2-吡啶偶氮)-5-二甲氨基苯胺与钯显色反应的研究

本文研究了5-Br-PADMA与钯的显色反应,在0.2～3.0mol/L HClO_4溶液中,试剂与钯形成最大吸收峰位于609nm,表观摩尔吸光系数ε为8.2×10~4L·mol~(-1)·cm~(-1)的青蓝色配合物。钯含量在0～35μg/25ml范围内符合比尔定律。大量常见金属离子及十倍量的铂、金、铱、铑和钌等贵金属离子不干扰钯的测定。所拟方法简便、快速、选择性高且测定结果稳定。直接应用于含钯样品的分析,结果满意。     

Rapid and Sensitive Spectrophotometric Determination of Hafuium(IV) With 2-(5-Bromo-2-Pyridylazo)-5-Diethylaminophenol

Abstract

Hafnium(IV) reacts with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol in the pH range 3.3–11.0 to yield a sparingly soluble red-coloured chelate that can be dissolved with Triton X-100. Effect of initial pH of metal ion and order of addition of reagents was studied in detail. The 1:3 complex adheres to Beer's law over the concentration range 0.02–1.12 μg/ml of Hf(IV), has a molar absorptivity 1.33x10⁵ 1 mol^?1cm^?1, Sandell sensitivity 1.3 ng cm^?2, formation constant (log K) 11.94 and the method had a relative standard deviation of ± 1.5%. Effect of 60 diverse ions on the determination of hafnium(IV) was studied. This fairly selective method is the most sensitive so far reported for the spectrophotometric determination of hafnium(IV).     

Some Arylidene-2-Pyridylhydrazone Derivatives as Reagents for Spectrophotometric Determination of Palladium (II)

Abstract

A method for spectrophotometric determination of palladium by complexation with Arylidene-2-pyridylhydrazone derivatives in 50% (V/V) ethanolic solution are described-Pd(II) forms a 1:1 complex with the reagents. Beer's law is obeyed over the range 0.2-6.5 μg ml^?1. The effect of pH, effect of excess reagent, stability of complexes as well as the tolerance amount of many metal ions have been reported. The method is applied, with fair accuracy, to the determination of pd(II) in synthetic solutions.     

2－（5－Br－2－吡啶偶氮－5－二乙氨基）－酚与铑的显色反应的研究及应用

本文研究了２－（－５－Ｂｒ－２吡啶偶氮－５－二乙氨基）－酚与铑（Ⅲ）的显色反应。在ｐＨ为４．０的邻苯二甲酸氢钾缓冲液介质中，Ｒｈ（Ⅲ）与试剂形成稳定的橙红色络合物，其组成比为１：４，最大吸收波长为４９０ｎｍ，表现摩尔吸光系数为１．３×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。铑含量在０～４μｇ／１０ｍＬ范围内服从比尔定律。     

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.     

氯化钯与4-(2-吡啶偶氮)间苯二酚、硫酸四苯锑形成的离子缔合物的结构与性质研究

本文对离子缔合物[(C_6H_5)_4Sb~+,PdCl(C_(11)H_7N_3O_2)~-]进行了制备,经元素分析、红外光谱和核磁共振谱分析,确定了络合物的组成和结构,并测定了其吸收光谱、电导率和稳定常数。考察了络合物在水中的存在状态及其电荷性质,并对其形成机理进行了初探。     

Selective Extractive Spectrophotometric Determination of Palladium (II) with Di-2-Pyridyl Ketone 2-Pyridyl-Hydrazone (DPPH)

Abstract

Palladium (II) reacts with DPPH in slightly acid medium to form a red colored complex stable in presence of EDTA and extractable into chloroform.

These properties of the Pd(II)-DPPH complex were used for the selective extractive spectrophotometric determination of palladium(II) in presence of several tested cations.     

显色剂2-(5-羧基-1,3,4-三氮唑偶氮)-5-二乙氨基苯甲酸与钯(Ⅱ)的显色反应研究

研究了显色剂2-(5-羧基-1,3,4-三氮唑偶氮)-5-二乙氨基苯甲酸(CTZDBA)与钯(Ⅱ)的显色反应。结果表明,Pd(Ⅱ)与CTZDBA生成稳定的1∶2的紫红色配合物,其最大吸收波长为548 nm,配合物的表观摩尔吸光系数为9.32×104L.mol-1.cm-1,Pd(Ⅱ)质量浓度在0.08~0.8 mg/L范围内符合比耳定律。该方法可不经分离直接测定钯碳催化剂和钯纳米碳催化剂中的微量钯,测定结果与原子吸收法(AAS)基本相符。     

反相高效液相色谱测定钴和镍的1-(5-溴-2-吡啶偶氮)-2-萘酚-6-磺酸螯合物

研究了1-(5-溴-2-吡啶偶氮)-2-萘酚-6-磺酸与钴(Ⅱ)和镍(Ⅱ)之螯合物的衍生和液相色谱分离条件。于Zorbax ODS柱上,用含0.01mol/L HAC-NaAc(pH 5.5)的乙腈-四氢呋喃-水(24:5:71,V/V)作流动相,流速0.7ml/min淋洗,于570nm检测。本方法已用于镍矿、催化剂回收液和人发样品的分析。     

1-(2-吡啶偶氮)-2-萘酚-镱二元络合物近红外发光法测定镱

基于金属指示剂 1 (2 吡啶偶氮 ) 2 萘酚 (PAN)对稀土离子Yb3+ 的近红外发光的敏化作用 ,建立了Yb3+ 的定量分析方法。方法的线性范围为 1 .0× 1 0 - 6 ～ 8.0× 1 0 - 6 mol L,检测下限为 1 .0× 1 0 - 6 mol L ,相对标准偏差为 3 .2 %。该方法适用于在混合稀土样品中选择性地测定Yb3+ 的含量。     

新试剂2-(5-硝基-2-吡啶偶氮)-5-二甲氨基苯甲酸分光光度法测定微量钴

本文报道用新试剂2-(5-硝基-2-吡啶偶氮)-5-二甲氨基苯甲酸分光光度法测定微量钴。配合物的表观摩尔吸光系数为1.31×10~5L·mol~(-1)·cm~(-1),Co∶5-NO_2-PAMB=1∶2,Co浓度在0～14μg/25mL范围内服从比耳定律。用于金属有机化合物中微量钴的测定,结果与理论值相符。     

Selective Determination of Trace Mercury (II) after Preconcentration with 4-(2-Pyridylazo)-Resorcinol-Modified Nanometer-Sized SiO2 Particles from Sample Solutions

A rapid, selective method that utilize 4-(2-Pyridylazo)-resorcinol (PAR)-modified nanometer SiO₂ (nanometer SiO₂–PAR) as a new solid-phase extractant for preconcentration of trace mercury (II) has been developed. The adsorption property of nanometer SiO₂–PAR for metal ions was studied by selectively extracting different metal ions from aqueous solutions. The results revealed an excellent affinity of the nanometer SiO₂–PAR for mercury (II) in presence of interfering metal ions at pH 4. The main parameters of solid-phase extraction such as shaking time, elution and sample dilution effect were studied. The extractant shows rapid kinetic sorption, and the adsorption equilibrium of mercury (II) on nanometer SiO₂–PAR was achieved in less than 2 min. The adsorbed mercury (II) was easily eluted by 4 mL of 6 mol L⁻¹ HCl. The maximum preconcentration factor was 50. The maximum static adsorption capacity was 276 μmol g⁻¹ at pH 4. The detection limit (3σ) was 0.43 μg L⁻¹ for cold vapor atomic absorption spectrometry (CVAAS), and the relative standard deviation of the eight replicate determinations was 2.4% for the determination of 2.0 μg of Hg(II) in 100 mL water sample. The method was applied to the determination of trace mercury (II) in sample solutions with satisfactory results.     

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.     

铁、钴和镍的2-(6-溴-2-苯并噻唑偶氮)-5-二乙氨基苯酚螯合物的高效液相色谱研究

分别于Shim-pack PNH_2和Zorbax CN柱上,研究了Fe(Ⅱ)、Co(Ⅱ)和Ni(Ⅱ)与6-Br-BTADAP之螯合物的HPLC分离条件;提出了于Shim-pack PNH_2柱上,用环己烷-乙酸乙酯-异丙醇(48:40:12,V/V)作流动相(1.0m/min)的HPLC同时测定此三元素的新方法。校正曲线之线性范围是0.025～4.0ppm Fe(Ⅱ)、0.1～2.0ppm Co(Ⅱ)和0.05～2.5ppm Ni(Ⅱ),其绝对检出限分别是0.61、0.40和0.20ng。异离子:Cd(Ⅱ)、Cu(Ⅱ)、Hg(Ⅱ)、Mn(Ⅱ)、Pb(Ⅱ)、Zn(Ⅱ)和Fe(Ⅱ),无干扰。本方法已应用于实际样品的分析。     

Spectrophotometic Determination Of Tin In Steels With2-(5-Nltro-2-Pyridylazo)-5-[N-n-Propyl-N-(3-Sulfopropyl)Amino]phenol

ABSTRACT

A highly sensitive azo dye, 2-(5-nitro-2-pyridylazo)-5-[N-n-propyl-N-(3-sulfopropyl)amino]phenol (Nitro-PAPS), is used as a colorimetric reagent for the determination of tin(IV) content. Nitro-PAPS reacts with tin(IV) to form a water-soluble complex in 1.0 M acetic acid. Full color development is attained within 5 minutes, and maintains constant absorbance for at least 24 hours. The apparent molar absorptivity is 7.7 x 10⁴ dm³ mol^?1 cm^?1 at a maximum wavelength of 580 ran. Beer's law is obeyed for tin(IV) in the range of 0-1.2 μg ml^?1. The proposed method is successfully applied to the determination of trace amounts of tin in steels.