Full Description ADOPTED_FROM:EN ISO 17380:2013 ISO 17380:2013 specifies a method for the photometric determination of the total cyanide and easily-liberatable cyanide content in soil using automated distillation/continuous-flow analysis. ISO 17380:2013 applies to all types of soil with cyanide contents above 1 mg/kg on the basis of dry matter, expressed as cyanide ion.