A new layer material consisting of stannic arsenate get mixed with silica gel G was developed and utilized for normal-phase and reversed-phase thin-layer chromatography (TLC) of metal ions. The analytical potential of tri-n-butylphosphate (TBP) as impregnant as well as eluent has been exploited. Separation of coexisting nickel, cobalt, and iron ions from acidic and ammoniacal solutions on stannic arsenate silica gel G (10:1 w/w) mixed sorbent layers impregnated with 0.2-M tri-n-butylphosphate in acetone and 1.0 M KSCN-5.0 M HCl-1.0 M NaCl (8:1:1) mobile phase is obtained. Effect of pH of sample, loading amount of analyte, and the presence of amines, phenols, and anions on the separation of Ni2+ from Co2+ was carried out to optimize the experimental conditions. The identification and separation of Ni2+, Co2+, and Fe3+ from distilled water, seawater, industrial wastewater, high-speed steel sample, and geological samples was achieved.