Extraction of the Total Cyanide in Soil with a New Distillation Collector

The total cyanide in soil was extracted with DCS-C12 distillation collector, and then determined as described in HJ 745-2015. The optimized conditions found were as follows: ① time of distillation: 80 min; ② temperature of reaction: 125 ℃; ③ amount of 50 g·L-1 stannous chloride solution added: 1.0 mL; ④ amount of H3PO4 added: 5.0 mL. The proposed method was applied to the analysis of simulated soil samples, giving results in consistency with those obtained by the GB method, with RSD′s (n=6) in the range of 6.5%-9.4%. Test for recovery was performed by standard addition method, giving values of recovery in the range of 86.6%-108%.