Spectrophotometric determination of microamounts of gallium in pure iron

Abstract

The photometric method for the determination of microamounts of gallium (150ppm) with Rhodamine B was studied, and the extraction method using a methylisobutylketone-benzene mixture was applied for the first time to a pure iron analysis as follows.One tenth g. of sample is decomposed with 20 ml of hydrochloric acid (1:1) (if necessary a few drops of hydrogen peroxide is added), and is diluted with hydrochloric acid (1 : 1) to about 20 ml. After adding 2 ml of titanium trichloride solution (17%), the solution is let stand for 15 minutes at room temperature. Two ml of Rhodamine B solution (0.5%), and 1 ml of butylcellosolve solution (1 : 2) are added, and the solution is shaken. for 2 minutes with 10 ml of the mixture of benzene and methylisobutylketone (6.5 : 1). Gallium is determined by measuring the absorbance of the organic layer at 562 mμ.Twenty μg of each element of Al, As, B, Ca, Ce, Co, Cr, Cu, Mg, Mn, Mo, Nb, Ni, P, Pb, Si, Sn, Ta, Ti, V, W, and Zn do not interfere. The time required is about 40 minutes.