Sorption-colorimetric and naked eye determination of germanium as ion associates of GeMo12O40 4- with triphenylmethane dyes. The sorption of the ionic associates (IA) of 12-molybdogermanat with astrafloxin (AF) on filter paper was studied. The colored scales for naked eye detection and dependence of chromaticity coordinates from the germanium (IV) concentration were obtained. The methods were applied to the determination of germanium (IV) in coked coal, iron ore, and in waters in the concentration range from 4• 10-8 to 1• 10-6 mol•l-1.