Simultaneous determination of zinc and cobalt or nickel by high frequency polarography: Study of trace elements in food. I

A high frequency polarographic method for simultaneous determination of zinc and cobalt or zinc and nickel has been studied in tetramethylammonium bromide supporting electrolyte. Application of the high frequency of 100kc among 50kc, 100kc, 250kc, 500kc and 1000kc gave a good result, and calibration curves were linear in the range of 5×10-7 to 2.6×10-5M for zinc, 5×10-6 to 1×10-4M for cobalt and nickel, respectively. It is possible to determine zinc coexisting with 100 times of cobalt and nickel in 0.5M supporting electrolyte solution at 100kc and H. F. voltage 0.6V. In the case of cobalt and nickel in solution containing zinc, the amounts of zinc must not exceed 10times of nickel and 5times of cobalt.