| Abstract: | Abstract The N-acetyl-L-methionine electrode is based on a coupled enzymatic system consisting of acylase and L-amino acid oxidase with an ammonia gas sensor; conditions of imobilization are optimized. N-acetyl-L-methionine in the range 4×10?5–2×10?3M gives a linear potential vs. log(concentration) plot with a response time of 2–5 min over the range specified. This electrode combined with an L-methionine electrode, based only on L-amino acid oxidase and an ammonia gas sensor, can be used for the determination of both substrates in mixtures, thus extending the feasibility of the method. Acylase (0.1–2.00) is determined in aqueous solutions by adding N-acetyl-L-methionine to the sample, and measuring the ammonia evolved with the gas-sensing electrode. |
