Determination of cyanide in biological materials

Abstract

After thawing the frozen biological materials, pretreatment for the determination of cyanide in biological materials were carried out by aeration method at pH 5.5 and distillation method at pH 5.0 for free cyanide and distillation method at pH 2.0 for total cyanide based on the determination of cyanide in water defined by JIS K 0102. The conditions for sample treatment were examined thoroughly and established as follows; 1) Fish samples : The aeration time in aeration method was required 12 h at 50 °C. The primary distillate volume was required about 140 ml in distillation method at pH 2. 2) Aquatic plant: The aeration time in aeration method was required 24 h. The primary distillate volume for distillation method at pH 2 was required about 190 ml. 3) Algae sample: The primary distillate volume was required about 190 ml in dlistillation method at pH 5.5 and about 140 ml in distillation method at pH 2 respectively. Although the analytical results for free cyanide were not reproducible enough. The recovery of total cyanide gave sufficient results.