A RAPID AND SENSITIVE MICROBIAL BIOSENSOR FOR ACETIC ACID DETERMINATION IN AIR

A rapid and sensitive microbial biosensor for acetic acid determination in air was developed. The microbial biosensor is based on the respiratory activity of the microbial cells estimated by the oxygen consumption due to the metabolic activity in the presence of substances. The results showed that the optimum pH, temperature and concentration of buffer solution were 6.48, 33 degree C and 0.01mol/L respectively in the determination process for acetic acid. The linear range between electric current decrease and acetic acid concentration was from 5 to 30mg/L and the regression equation was y = 0.51x+1.66 (correlation coefficient 0.9998). 23 kinds of interferential substances, which own the similar chemical characters and molecular weights as acetic acid, were determined simultaneously as interferential substances in the experiment. The biosensor was found to have an extend activity of 90 days with more than 600 determinations.