二溴邻硝基偶氮胂分光光度法测定微量铂  

Spectrophotometric determination of micro platinum(Ⅱ) with dibromo-o-nitro-arsenazo

作　　者：徐国想[1] 马卫兴[1] 周洪英[1] 邹桂娟[1] 

机构地区：[1]淮海工学院化学工程系,江苏连云港222005

出　　处：《冶金分析》2007年第4期55-58,共4页Metallurgical Analysis

基　　金：江苏省高新技术产业化项目(JM01-89);江苏省高校自然科学研究计划项目(02KJD150014)

摘　　要：研究了溴化十六烷基三甲铵(CTMAB)存在下,铂(Ⅱ)与3-[(2-胂酸苯基)偶氮]-6-[(4,6-二溴-2-硝基苯)偶氮]-4,5-二羟基-2,7-苯二磺酸(即二溴邻硝基偶氮胂)的显色反应,建立了一种测定微量铂的光度分析法。试验表明,在pH6.5的HAc-NaAc缓冲溶液中,铂与二溴邻硝基偶氮胂形成组成比1∶3的紫红色络合物,该络合物的最大吸收峰位于526nm,表观摩尔吸光系数ε=1.12×105L.mol-1.cm-1。在10mL显色溶液中,铂量在0.03～14μg范围内符合比尔定律。方法已用于铂催化剂和铂精矿中微量铂的测定,回收率为98.1%,99.4%,相对标准偏差为0.23%,0.83%。The color reaction of 3-[ （2-arsonophenyl） azo]-6-[ （4,6-dibromo-2-nitrophenyl） azo]-4,5-dihydroxynaphthalene-2,7-disulfonic（ abbreviated as DBONAA, dibromo-o-nitro-arsenazo） with platinum（Ⅱ） was studied in the presence of cetyl trimethylammonium bromide （CTMAB）, and a new spectrophotometric method for the determination of micro platinum was established. The experimental results show that platinum（Ⅱ） reacts with DBONAA to form a stable mauve complex with molar ratio of 1 ： 3 in HAc - NaAc buffer medium at pH 6.5.The maximum absorption wavelength and apparent molar absorptivity are 526 nm and 1.12 × 10^5 L·mol^- 1 ·cm^- 1 ,respectively.Beer＇s law is obeyed in the range of 0.03 - 14 μg in 10 mL solution for Pt（Ⅱ）.The method has been applied to the determination of platinum in the platinum catalyst and platinum concentrate with recovery of 98.1%, 99.4% and relative standard deviation of 0.23%, 0.83%.

关 键 词：二溴邻硝基偶氮胂 铂 光度法 溴化十六烷基三甲铵 

分 类 号：O657.3[理学—分析化学]