高酸度条件下单波长、双峰双波长分光光度法测定铬(Ⅵ)  

The Determination of Chromium(Ⅵ)in the High Acidic Medium by Mono-and Dual-Wavelength Spectrophotometry

作　　者：王振清[1] 许光惠[1] 沈含熙[1] Wang Zhenqing;Xu Guanghui;Shen Hanxi(Department of Chemistry,Nankai University,Tianjin)

机构地区：[1]南开大学化学系

出　　处：《高等学校化学学报》1987年第4期322-324,共3页Chemical Journal of Chinese Universities

摘　　要：铬(Ⅵ)的测定,在金属材料的分析中具有重要意义。目前,铬的测定仍采用二苯卡巴肼法,该法的灵敏度虽较高(ε=34600),但由于显色剂的稳定性很差,显色剂溶液和工作曲线需当天配制和绘制,除给操作带来许多麻烦外,还造成大量试剂的浪费。A simple and rapid spectrophotometric method for the determination of chromium(Ⅵ)with 9-orthochloropheny1-2,3,7-trihydroxyfluorone(o-Cl-pF)has been investigated.This method is based on the formation of a complex in the hydrochloric and phosphoric acid medium(0.4N HCl+3N H_(3)PO_(4)).The complex has an absorption maximum at 497nm.The value of molar absorption cofficient is 2.33×10^(4)atλ_(515nm).Beer's law is obeyed over the range 0-30μg/25ml of Cr.The two wavelengths for the determination of 0-10μg/25ml of Cr by using dual-wavelength method are 462 and 497nm.By using the proposed method,the Cr contents in alloy and metallic materials were determined with satisfactory results.

关 键 词：双峰双波长分光光度法 工作曲线 二苯卡巴肼 酸度条件 铬(Ⅵ) 单波长 金属材料 显色剂 

分 类 号：O65[理学—分析化学]