engleski

Potentiometric and amperometric determination of cyanide in alcohol beverages

It is well known that the toxicity of cyanide is due to inhibition of respiration activity of yeasts by its binding to cytochrome oxidase complexes. These phenomena can be used for development of a cyanide biosensor consisting of oxygen electrode with immobilised S. cerevisiae. The cyanide present in beverage samples inhibits the electron chain reaction of respiration system in mitochondria decreasing the respiration activity. Fruit brandies in which cyanide contents were determined by potentiometry were used for determination of total respiration activity of Saccharomyces cerevisiae. The comparison of two methods (ISE-potentiometry and measurement by amperometric biosensor) for the determination of cyanide was investigated. Effect of cyanide concentration on microbial cells was observed by measuring the decrease of the current until a steady-state was reached. When a steady-state current was reached, the microbial electrode was immersed in pure growth medium to recover. The recovery depends on the cyanide concentration in brandy present in growth medium. The correlation between results obtained by two methods is good, although the cyanide concentrations obtained by ISE-potentiometry seemed to be slightly lower than those obtained by amperometric microbial biosensor.

cyanides; potentiometric sensor; amperometric sensor; saccharomyces cerevisiae

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