ラネーニッケル還元分解によるシアン化物及びシアン錯体の微量定量

抄録

A simple and rapid method for the microdetermination of nitrogen in cyanides, cyanocomplexes and apricot kernel water is proposed. The method is based on the reductive decomposition of cyano group to the mixture of ammonia and methylamine in alkaline medium by using Raney nickel and subsequently on the titration of the mixed bases which are distilled and collected in 4% boric acid, using 0.01 N HC1 as titrant. The reduction and the distillation were carried out with the improved micro Kjeldahl apparatus previously reported by the author. A (510) mg of sample was taken in the distillation flask, and the appropriate quantity of Raney nickel powder (0.35 g for ordinary cyanides, 0.45 g for cyanocomplexes) was added, the powder then being washed down with (510) ml of water. After the whole apparatus was assembled by glass joint, 2 ml of alkaline solution (30% NaOH) and 5 ml of water were run in through the introductory funnel and the condenser tip was put beneath the solution of boric acid in the receiver. The distillation flask was heated gradually by a burner flame under aeration (one or two bubbles per second) till red colored boric acid solution with methylred turned to pale yellow. After the violent distillation for fifteen minutes, the microtitration with 0.01 N HCl was carried out in that the blank value was suggested to be substracted from the experimental value. The standard deviation and the coefficient of variation were (0.20.1)% and (1.10.5)%, respectively, in a series of experiments. NO₃^-, NO₂^-, SCN^-, CNO^-, NH₄⁺ and volatile amines interfere the analysis.