选择性试剂2-(4-安替比林偶氮)-5-二甲氨基苯甲酸的合成及其分析应用

Synthesis and Application of the Selective Chromogenic Reagent 2-(4-Antipyrinylazo)-5-N,N' -dimethylaminobenzoic Acid

关键词:  高效选择性试剂  2-(4-安替比林偶氮)-5-二甲氨基苯甲酸  合成  应用  钯

Key words:  selective reagent  2-(4-Antipyrinylazo)-5-N,N'-dimethylaminobenzoic acid  synthesis  application  palladium

摘要:

改变安替比林偶氮的取代基团,合成出一种新的选择性试剂2-(4-安替比林偶氮)-5-二甲氨基苯甲酸(AADMB),并采用薄层层析法、元素分析法、红外光谱法和核磁共振波谱法鉴定AADMB。建立以AADMB为试剂的分光光度法测定Pd(Ⅱ)。结果表明,在弱酸性介质中Pd(Ⅱ)与AADMB反应形成红色的配合物,常见金属离子均无较强的干扰,说明AADMB是一种选择性较强的杂环偶氮试剂。在阳离子表面活性剂氯代十六烷基三甲铵存在下,该配合物的最大吸收波长在485nm,表观摩尔吸光系数为2.04×10⁴ L·mol^-1·cm^-1,钯量在0~25μg/25ml内遵守比尔定律,检测极限为0.2μg。建立的新分析方法应用于测定活性碳及石钯渣中的微量Pd,测定结果接近活性碳及石钯渣中Pd的标准含量,回收率分别为96%和95%。

Abstract:

The selective chromogenic reagent,2-(4-antipyrinylazo)-5-N,N'-dimethylaminoben-zoic acid(AADMB) is synthesized, and analyzed by the thin-layer chromatography,the element analysis,infrared spectrum,the magnetic resonance imaging.In the weak acid medium,the reagent reacts with palladium ions and creates a red complex.The determination of palladium is hardly interfered with the common metal ions.In the presence of positive ionic surfactant,this complex has an apparent molar absorptivity 2.04×10⁴ L·mol^-1·cm^-1.at 485 nm Beer's law is obeyed over the range of 0~25 μg/25 ml for palladium ions.The detection limit is 0.2 μg.The suggested method is applied to the determination of microamounts of palladium in the catalysts and slag which contain palladium.The recovery is 96% and 95%,respectively.