The tri-n-butyl orthophosphate:acetic acid:acetone solvent system has been studied for the paper chromatographic separation of the oxidation states of 16 elements. The separation of As3+, As5+; Cr3+, Cr5+; Fe2+, Fe3+; Hg+, Hg2+; Mn2+, Mn3+, and Mn7+; Sb3+, Sb5+; Tl+, Tl3+; Cl−, ClO3−Br−BrO3−; I−, IO−3; P2O4-7PO3-4, and PO−3has been achieved. Multiple zones obtained with Fe3+and Tl3+species are discussed.