邻硝基苯基荧光酮——溴化十六烷基三甲基铵分光光度测定铬(V1)

Spectrophotometric Determination of Chromium (VI) with o-Nitrophenylfluorone - Cetyltrimethylammonium Bromide

本文研究了Cr(V1)同邻硝基苯基荧光酮(o-NPF)和溴化十六烷基三甲基铵(CTMAB)在pH4.6～6.0的HAc-NaAc介质中的显色反应,表明该紫红色络合物的最大吸收在580nm,摩尔吸光系数为1.14×10~5cm^(-1).mol.L^(-1),0～10 μg/25ml服从比尔定律,在有过量CTMAB存在下,Cr(Vl)与o-NPF的络合比为1:2。研究了外来离子对测定铬的影响,提出的方法可用于测定微量铬,结果满意。

The color reaction of chromium with o-nitrophenylfluorone(o-NPF) and cetyltrimethylammonium bromide (CTMAB) has been investigated in the medium of HAc-NaAc at pH range 4.6-6.0. It shows that the violetred complex has a maximum absorption at 580nm and its molar absorptivity is 1.14 × 105cm-1.mole-1.L.Beer's law obeyed in the range ofo-10μg Cr / 25ml. The ratio of Cr (VI) to o-NPF in the presence of exceed CTMAB is 1:2. The effects of foreign ions have been studied.The method can be used to determine trace Cr, and the results were satisfactory.