微量铂的2-(3,5-二氯-2-吡啶偶氮)-5-二甲氨基苯胺激光热透镜光谱法测定  

Laser Thermal Lens Spectrometric Determination of Trace Platinum with 2-(3,5-Dichlor-pyridylazo)-5-dimethylaminoaniline

作　　者：张小玲[1] 闫宏涛[1] 

机构地区：[1]西北大学化学系,陕西西安710069

出　　处：《分析测试学报》2003年第1期34-37,共4页Journal of Instrumental Analysis

基　　金：陕西省自然科学基金资助项目 (99H07)

摘　　要：基于2_(3,5_二氯_2_吡啶偶氮)_5_二甲氨基苯胺(3,5_diCl_PADMA)与铂的显色反应 ,以激光热透镜光谱法测定了微量铂 ;实验表明 ,在强酸性介质中 ,Pt(Ⅳ)与3,5_diCl_PADMA显色形成稳定的蓝色络合物 ,络合物最大吸收波长位于634nm处 ,与所用激光器输出激光波长λ632nm 匹配较好 ,从而建立了激光热透镜光谱法测定铂的方法 ;铂质量浓度分别在0.005～0.04mg/L和0.025～0.4mg/L范围内与激光热透镜信号强度呈线性关系 ,方法灵敏度高 ,选择性、重现性好 ,用于样品测定 。A novel method for the determination of trace platinum based on the colour reaction between 2 _ (3,5 _ dichlor _ pyridylazo) _ 5 _ dimethylaminoaniline(3,5 _ diCl _ PADMA) and platinum by laser thermal lens spectrometry was proposed. It is shown that platinum reacts with 3,5 _ diCl _ PADMA to form a stable blue complex in a strong acidic medium, such as 0.04～0.48 mol/L H2SO4 and 0.01～0.06 mol/L HCl. In the presence of acetone this complex has a maximum absorption at wavelength of 634 nm which is a well _ matched wavelength for the laser beam used. Based on this characteristic the title method was developed. The method is simple, selective and sensitive. The sensitivity of this method was about 2 orders of magnitude higher than that of conventional spectrophotometric method. The linear ranges of 0.005～0.04 mg/L and 0.025～0.4 mg/L for platinum(Ⅳ), and detection limit of 2 μg/L were obtained. The method has been applied to determine trace platinum in alloy and catalyst samples with satisfactory results.

关 键 词：测定 激光热透镜光谱法 铂 2-(3 5-二氯-2-吡啶偶氮)-5-二甲氨基苯胺 微量分析 

分 类 号：O614.826[理学—无机化学] O657.3[理学—化学]