微乳液增敏5’-硝基水杨基荧光酮分光光度法测定痕量镓

Spectrophotometric determination of trace gallium with 5'-nitrosalicylfluorone in microemulsion medium

研究了5L硝基水杨基荧光酮与金属离子镓（Ⅲ）的显色反应。实验结果表明，在pH2.0的盐酸溶液中，由辛基苯基聚氧乙烯醚（OP），正丁醇，正庚烷和水按5．0：3．3：0.8：90．9的质量比组成的微乳液存在下，镓（Ⅲ）与试剂形成1：2的紫红色络合物，络合物的最大吸收峰在524nm波长处，表观摩尔吸光系数为2．03×10^5L·mol^-1·cm^-1。镓（Ⅲ）含量在0～240ug／L范围内符合比尔定律。所拟方法用于煤粉中痕量镓（Ⅲ）的测定，相对标准偏差为1.4％～2.6％，测定结果与罗丹明B分光光度法相符。

The color reaction of 5＇-nitrosalicylfluorone with gallium in the presence of OP microemulsion medium is studied. Experimental results show that in hydrochloric acid at pH2.0 and in the presence of microemulsion（m（OP） ：m（n-butanol） ： m（n-heptane） ：m（water）=5.0 ： 3.3 ： 0.8 ： 90.9）, gallium with reagent forms 1 ：2 stable purple complex, of which the maximum absorption wavelength is at 524nm. The apparent molar absorptivity is 2.03 × 10^5 L ·mol^-1 · cm^-1. Beer＇s law is obeyed in the range of 0--240 ug/L for gallium. The method has been applied to the determination of gallium in coal with RSDs of 1.4%-2.6% and the determination results are in consistent with those of rhodamine B spectrophotometry.