APPLICATION OF COUNTERCURRENT CHROMATOGRAPHY TO THE PURIFICATION OF CHEMICAL REAGENTS

Countercurrent chromatography has been employed for the purification o f solid chemical reagents, such as (NH4)(2)SO4, NH4HSO4, NH4F and NH4C l form a number of most common metal impurities (Fe, Al, Zn, Cu, Co, C d, Ni, Cr, Ca, Mg, K) in order to gain high-purity reagents. After eva poration these can be used for fusion decomposition purposes in trace analysis of various refractory materials (e.g. high tech ceramics). N, N-hexamethylenedithiocarbamic acid, 8-hydroxyquinoline, dibenzo-18-cro wn-6 and dicyclohexano-18-crown-6 were used as extracting reagents.