Analytical applications of m- and p-phenylene-di(1-tetrazoline-5-thione) Gravimetric determination of ruthenium(lll) in presence of large amounts of rhodium (III)

A simple and rapid method is described for the gravimetric determination of ruthenium(III) with two new isomeric reagents, m-and p-phenylene-di(1-tetrazoline-5-thione). Solutions containing milligram amounts of ruthenium(III)on treatment with the acetone or alcohol solutions of the reagents at pH 5.5-7.0 give a quantitative yield of an intensely green insoluble 1:1 complex which can be easily filtered off and dried at 110-115 degrees . Amounts of ruthenium down to 0.5 mg can be determined with fairly good accuracy and precision. Even large amounts of rhodium do not cause any interference. The following cations interfere: Pd(II), Pt(IV), Au(III), Ir(IV), Bi, Fe(III), Cu(II), Hg(I), Hg(II), Pb, Cd, T1(I) and Ag.