Tiquira is an alcoholic beverage made of fermented and distilled manioc root (Manihot esculenta). The presence of toxic species such as carbamates, methanol, heavy metals and cyanide in this beverage is considered crucial to the quality of this important product of northern Brazil. This article proposes an analytical procedure involving the use of voltammetry in the differential mode after the sample is distilled in the presence of 0.1 mol.L-1 of nitric acid. The new methodology was compared (test T) with a standard method for determining cyanide, indicating that the methods are equivalent from thee standpoint of statistics and thus confirming the viability of the proposed methodology. The conditions established (volume of the adsorbent solution = 100.0 mL; pH = 10; potential range = -0.5 to -0.1 V; scan rate = 20 mV.s-1) showed high reproducibility and allowed for the construction of analytical curves with values close to 0.999. The "tiquira" showed an average cyanide content of 2.8 x 10-5 mol.L-1 ± 2.4 x 10-6 mol.L-1 for n = 5, i.e., about 150 times higher than the acceptable content in drinking water.
cyanide; firewater; voltammetry
