出版社：National Institute of Occupational Safety and Health
摘要：While both nickel (II) oxide and nickel (III) oxide affect the human body, nickel (III) oxide may be more toxic since it could act as an oxidizing agent. Hence, it is necessary to perform differential determinations of nickel (II) oxide and nickel (III) oxide in airborne particulate substances. Such determinations have not been performed because nickel (III) ions are unstable in aqueous solutions. Nickel (III) oxide was found to release molecular oxygen with sufficient reproduci-bility when it was dissolved in 1 N hydrochloric acid solution by stirring for 20 minutes. The released and dissolved oxygen in the solution was then determined by sampled-dc polarography. The diffusion current was proportional to the amount of nickel (III) oxide applied. However, slight deviation from the linear relationship between the current and amount of sample was observed. This might be caused by the coexistence of the polarographic maximum current and the reduction of oxygen by chloride ions. A third-order polynomial was fitted to the data ob-tained with the standard samples by the least squares method ; it was used as the calibration curve for the determination of testing samples. Using the present method, nickel (III) oxide in the range from 5 mg to 50 mg in the mixure with nickel (II) oxide was determined with an error of only a few percent. Nickel (III) oxide of about 1 mg was determined with an error of about 10%.
关键词：Key words : Determination of nickel (III) oxide-Differential determination•Nickel (II) oxide-Nickel (III) oxide-Airborne particulate substances-Polaro-graphic analysis
