Flow injection amperometric and chemiluminescence individual and simultaneous determination of lysine and glucose with immobilized lysine oxidase and glucose oxidase

Flow injection amperometric and chemiluminescence methods for the individual and simultaneous determination of lysine and glucose by using lysine oxidase and glucose oxidase are described in this paper. The calibration graphs for lysine are linear over the range 1 × 10−5 − 1.6 × 10−4 and 2.05 × 10−7 − 2.75 × 10−5 M for amperometric and chemiluminescence detection respectively. The detection limits (3σ) for lysine are 5 × 10−6 M with amperometric and 4.0 × 10−8 M with chemiluminescence detection. The sample throughput rates are 80 and 100 h−1, respectively. Lysine and glucose concentrations can be monitored simultaneously in the range 1.5 − 9 × 10−5 M and 7 × 10−7−8 × 10−6 M with amperometric and chemiluminescence detection respectively. The interference effects of some amino acids and metal ions are examined. An on-line cation-exchange minicolumn is inserted into the chemiluminescence manifold to remove the interference effect of Fe2+ and Cu2+.