青酸化合物より揮發する青酸量と水素イオン濃度との關係 (第3報)

シアン水銀に就て

抄録

Mercuric cyanide was dissolved in three kinds of buffer solution, i.e. phosphoric acid-sodium phosphate, citric acid-sodium hydroxide, and tartaric acid-sodium hydroxide, and quantities of free hydrocyanic acid liberated were measured at temperatnres 15°, 37°, 60° and 100° at varying pH. No free hydrocyanic acid was detected at 15° in any of the buffer solutions; the highest coneentration of the liberated HCN was 0.00288 per cent at 37°, 0.0334 per cent at 60°, and 0.0772 per cent at 100°.
The amount of hydrocyanic acid liberated from mercuric cyanide solution is thus so small in the neighborhood of human temperature that its toxicity is of no significance. However, it is pointed out that the toxicity of the liberated HCN should be taken into consideration at lower values of pH and at temperatures above 60° depending on the time of contact and the presence of catalyzer, and that besides the toxicity of HCN that of the mercuric compounds should also be taken into account.