Gravimetric determination of zinc with 2-([omicron]-hydroxyphenyl)-benzoxazole

A gravimetric method of determining zinc with 2-(ο-hydroxyphenyl)-benzoxazole has been studied. Add ammonium tartrate as masking reagent to a sample solution containing zinc, and adjust pH of the solution to 12.513 with sodium hydroxide solution.Add the precipitant to the solution in excess 20 to 40% over the stoichiometric amounts for zinc, heat for 30 minutes at 7080°C, filter and dry the pale yellow precipitate for 3 to 4 hours at 150160°C, and weigh as Zn (C13H8O2N)2. By the present procedure, 1 to 50 mg of zinc could be determined rapidly with good precision as well as the oxine method. The effect of diverse ions on the determination of zinc was also examined. Ni, Co, Cd, Cu, and Pd interfered remarkably with the determination forming their complex salts. The method has been successfully applied to the determination of zinc in brass.