Nb(Ⅴ)-5-Br-PADAP-酒石酸-NaClO_3体系的极谱催化波

以Nb(Ⅴ)-5-Br-PADAP-酒石酸多元络合物分光光度法测定铌巳有研究,但Nb(Ⅴ)-5-Br-PADAP-酒石酸-NaClO_3体系的极谱催化波却未见报道。受宋俊峰等同志工作的启发,我们发现在稀硫酸介质中,当有NaClO_3存在时,Nb(Ⅴ)-5-Br-PADAP-酒石酸三元络合物于-1.0V左右(Vs.SCE)产生极灵敏的催化波,铌浓度在0.0014—0.14μg.ml~(-1)范围内,峰电流与浓度呈线性关系。本文讨论了该体系中铌催化波的条件及性质,拟定了示波极谱法测定痕量铌的方法。     

分光光度法测定微量铌的研究——用2-(5′-溴吡啶-2′-偶氮)-5-二乙胺基苯酚作显色剂

2-(5′-溴吡啶-2′-偶氮)-5-二乙胺基苯酚(简称5-Br-PADAP)的结构式为,在吡啶偶氮对位的苯环上存在一个强的助色团—N(C_2H_5)2,它与过渡金属离子如UO_2~(2 ),CO~(2 ),Fe~(3 ),Ni~(2 ),Zn~(2 ),Mn~(2 ),Bi~(3 )等的显色反应灵敏度一般都比PAR要提高一倍至几倍,其摩尔吸收系数多在10~5数量级。但用该试剂测定铌尚未见报道,根据铌(V)与PAR的显色反应,我们估计5-Br-PADAP可能与Nb~(5 )显色且灵敏度会更高,本文研究证实了这种预想。在含酒石酸的0.02～0.14N盐酸介质中,Nb~(5 )与5-Br-PADAP和酒石酸生成1:1:1的紫蓝色三元络合物,其吸收峰位于626nm,摩尔吸收系数为6.6×10~4。此法用于部分合金钢中铌的测定,比用硫氰酸盐、溴邻苯三酚红,PAR,氯代磺酚S,N-肉桂酰-N-邻甲苯羟胺,及噻唑偶氮-5-二甲胺基酚等显色剂的灵敏度都高,色泽稳定,选择性良好,样品不经分离可直接测定。     

钽(V)-酒石酸-5-Br-PADAP-十二烷基磺酸钠体系的显色反应

微量钽的测定,常用碱性染料萃取光度法,但有机溶剂污染环境,不利健康,故需寻求有效的水相光度测定微量钽的方法。刘新臣等曾用5-Br-PADAP测定钽,但未深入研究反应机理,并且铌要用纸色层对离。作者详细研究了该体系的反应条件,在0.5MH_2SO.溶液中,用不同辅助络合剂和表面活性剂进行实验,确定以酒石酸(Tar)作辅助络合剂,十二烷基磺酸钠     

溴邻苯三酚红-十六烷基三甲基溴化铵光度法测定钢中钽

文献报导,BPR在H_2O_2存在下能与钽生成紫蓝色化合物。我们发现,在酒石酸和EDTA存在下,Ta(V)与BPR和CTAB也可生成紫蓝色络合物,且草酸可掩蔽一定量的铌。在此基础上研究制定了测定钢中钽的光度法。在620毫微米下测得络合物克分子吸收系数为1.10×10~5。0—60微克Ta_2O_5/50毫升符合比尔定律。 (一)主要试剂 1.钽标准溶液:称取Ta_2O_5(99％以上),用焦硫酸钾熔融和25％酒石酸浸取熔块的方法配制成每毫升含200微克Ta_2O_5     

5-Br-PADAP萃取光度法测定矿石中微量钯

本文探讨了5-Br-PADAP与钯(Ⅱ)的显色条件及络合物组成。在1—2NH_2SO_4介质中,Pd(Ⅱ)可与5-Br-PADAP形成蓝色的稳定络合物。该络合物可被甲基异丁基甲酮等有机溶剂萃取。络合物最大吸收波长为590nm,摩尔吸光系数为4.3×10~4。本文拟定了火法试金富集后,用5-Br-PADAP萃取光度法测定矿样中钯的分析步骤。 5-Br-PADAP是近来出现的高灵敏度的显色试剂之一。曾用于铀、镓、锑、铜等多种元素的测定。对于钯与5-Br-PADAP的显色反应,有人也曾提到过,但未进行过详细     

矿石中微量钒分析方法的研究

胶束增溶光度法测定微量钒已有报导,用2-(5-溴-吡啶偶氮)-5-二乙氨基苯酚(5-Br-PADAP)-H_2O_2测定钒的方法也有报导。本文在此基础上研究了在表面活性剂8176存在下,用5-Br-PADAP光度法测定钒(V)的适宜条件及络合物的组成,提出了一个重现性好,灵敏度高,操作简便的测定矿石中微量钒的新方法。络合物(1:1)的最大吸收波长和表观摩尔吸光系数分别为590nm和9.06×10~4l·mol~(-1)·cm~(-1),最低检测限为0.008μg/ml,在0.2～16μgV(V)/25ml范围内遵守比尔定律,并满意地应用于硅酸盐和铁矿石中钒的测定。 1.主要试剂与仪器:     

新显色剂6,8-二磺酸萘偶氮氯磺酚与铌(Ⅴ)显色反应的研究及应用

本文研究了新显色剂6,8-二磺酸萘偶氮氯磺酚与Nb(Ⅴ)的显色反应和测定条件。在酸度为0.6～3mol/L盐酸时。络合物的组成比为Nb(Ⅴ):R=1:3,摩尔吸光系数为4.42×10~4L·mol·L~(-1)·cm~(-1)。可不经分离直接测定钢铁试样中的铌。     

2,3,7-三羟基-9-水杨基荧光酮分光光度法测定痕量铌

以酒石酸作为辅助络合剂,在表面活性剂溴化十六烷基吡啶存在下及pH 5.5的乙酸-乙酸钠缓冲溶液中,显色剂2,3,7-三羟基-9-水杨基荧光酮与铌(Ⅴ)形成稳定络合物,其最大吸收波长位于560nm处,据此提出了分光光度法测定铌钽矿浸出液中铌含量的方法。铌(Ⅴ)的质量浓度在4～240μg·L-1范围内符合比耳定律,表观摩尔吸光率为1.44×106L·mol-1.cm-1。方法用于铌钽矿样品中痕量铌的测定,测定结果与国家标准方法测定值相一致。     

新显色剂3′,4′-二羧基偶氮胂分光光度法测定铬(Ⅲ)

本文研究了新显色剂3＇,4＇-二羧基偶氮胂的合成及分光光度法测定铬(Ⅲ)的条件。铬(Ⅲ)与试剂在pH2.2时经水浴煮沸15分钟生成1:1蓝色络合物,络合物最大吸收在625毫微米处,摩尔吸光系数为4.7×10~4,铬量在0-1.0 微克/毫升范物内遵守比尔定律。方法能用于钢样中铬的测定。     

钼-羟胺-(5-Br-PADAP)三元络合物及其应用于钼的分光光度法测定

在弱酸性介质中,在有羟胺存在并煮沸的情况下,钼能与羟胺和2-[(5-溴-2-吡啶)偶氮]-5-(二乙氨基)苯酚(简称5-Br-PADAP)作用形成蓝色的不溶于水的三元络合物,但在聚乙二醇辛基苯基醚(简称OP)存在下可不析出沉淀。此三元络合物的组成为Mo(Ⅳ):NH₂OH:5-Br-PADAP=1:1:1,其最大吸收在600-605毫微米,摩尔吸光系数为4.8×10⁴,在10毫升显色液中含0.1%5-Br-PADAP溶液0.6毫升,钼量在30微克以下遵守比耳定律。我们采用在显色后加入混合掩蔽剂并煮沸的办法来消除共存离子的干扰,方法具有很高的选择性,尤其可在大量钨存在下直接测定钼。     

5—Br—PADAP快速光度法测定钢中铌

研究了用２－（５－溴－吡啶偶氮）－５－二乙氨苯基酚（５－Ｂｒ－ＰＡＤＡＰ）测定钢中铌显色条件，所拟方法简捷实用，可测钢中０．０１０％～６．００％的铌。     

Sensitive spectrophotometric determination of bismuth(III) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol

The complex of the reagent 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) with Bi(III) has been studied. The composition and stability of this complex have been determined. An analytical method for the spectrophotometric determination of Bi(III) using its complex with 5-Br-PADAP has been developed. Variables influencing the method such as pH, wavelength, and time have been studied. The limitations of this method and the effect of interfering ions have been investigated. Comparison of this method with other methods cited in the literature for the determination of Bi(III) is also included.     

因子分析法研究5-Br-PADAP-铌、钽显色体系

文用因子分析法对5-Br-PADAP-铌、钽显色体系进行研究,提出以浓度乘积因子rC_(Nb)C_Ta表示配合物间的交互作用。并以铌、钽混合液的已知浓度组成为目标进行变换分析,对铌、钽混合液进行了测定。     

Spectrophotometric determination of cadmium(II) using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol

The complex of cadmium with the reagent 2-(-5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) has been studied. The composition, stability constant, and free energy change of formation of the complex have been determined. A sensitive spectrophotometric method for the determination of cadmium has been developed and applied for a range of concentration of 0.4–4.0 μg/ml cadmium using the complex Cd-5-Br-PADAP. The optimum conditions for maximum sensitivity of determination such as standing time, pH, wavelength, and order of addition have been determined. The effect of foreign ions on this method has been also studied.     

Separation and simultaneous determination of niobium and tantalum in steel by reversed-phase high-performance liquid chromatography using 2-(2-pyridylazo)-5-diethylamino phenol as a pre-column derivatizing reagent

A method for the simultaneous determination of Nb and Ta in steel and alloy by reversed-phase high-performance liquid chromatography (RP-HPLC) was proposed. 2-(5-Bromo-2-pyridylazo)-5-diethylamino phenol (5-Br-PADAP) was used as a pre-column chelating agent to form a ternary complex with Nb(V) and Ta(V) and tartaric acid. The ternary complexes of Nb(V) and Ta(V) were eluted within 8 min on a C₁₈ column with a mobile phase of methanol-water (55:45, v/v) containing 10 mmol l⁻¹ acetate buffer (pH3.5) and determined with spectrophotometric detection at 598 nm. The detection limits for Nb(V) and Ta(V) were 0.60 and 0.72 μg l⁻¹, respectively, when the ratio of signal-to-noise is 3. The proposed method was used to analyze Nb and Ta in cast iron, alloy and stainless steel.     

Determination of V(V), Nb(V) and Ta(V) as their 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol chelates by reversed-phase HPLC

This paper reports the separation and determination of V(V), Nb(V) and Ta(V) by RP-HPLC using 5-Br-PADAP as a precolumn derivatizing reagent. On C(18) column, the three metal chelates can be separated on a baseline in 9 min with the mobile phase of methanol-water (59:41, v/v) containing tartaric acid (0.2%) and acetate buffer (pH 3.5, 10 mM). The detection limits of V(V), Nb(V) and Ta(V) are 0.13 ppb, 0.22 ppb and 1.79 ppb, respectively when S/N is 3. This method is simple and rapid, and has been used in mineral analysis with satisfactory results.     

用分光光度法连续测定血清中微量铜、锌的研究

研究了在ＴｒｉｔｏｎＸ－１００存在下,在ＰＨ８．０的乙醇介质中,用５－Ｂｒ－ＰＡＤＡＰ作为显色剂,应用分光光度法连续测定血清中的铜,锌。本法具有较高的灵敏度,Ｃｕ＾２＋－５－Ｂｒ－ＰＡＤＡＰ的ε为８．５０＊１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１,Ｚｎ＾２＋－５－Ｂｒ－ＰＡＤＡＰ的ε为９．６５＊１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１。铜线性范围为０－０．４５ｍｇ．Ｌ＾－１,锌线性范围为０－０．４０ｍｇ．     

Determination of fosfomycin by indirect spectrophotometric method

2-(5-Bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) is a sensitive photometric reagent for determination of zirconium, when fosfomycin is added, it can quantitatively replace 5-Br-PADAP by complexing with zirconium, thus, an indirect spectrophotometric method based on ligand exchange has been established. The detection wavelength is at 605 nm, and the apparent molar absorption coefficient was found to be 4.59x10(4) l mol(-1) cm(-1). Beer's law is obeyed in the range of 0-28x10(-6) M. The composition and stability constant of zirconium with 5-Br-PADAP and with fosfomycin has also been estimated. The proposed method is simple and reproducible, it was applicable to the analysis of fosfomycin from pharmaceutical manufacture.     

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.