APPLICATION OF A MICROFLUIDIC GAS-DIFFUSION UNIT TO FLOW INJECTION ANALYSIS OF L-LYSINE WITH AN L-LYSINE α-OXIDASE COLUMN

摘要

A fluorometric flow-injection analysis (FIA) system with an immobilized L-lysine α-oxidase column as a recognition element was developed and applied to determination of L-lysine by using a microfluidic gas diffusion device. The gas-diffusion unit consisted of a double tubing structure in which the outer tubing was made of PTFE (inner diameter: 1.0 mm, outer diameter: 1.5 mm) and the inner was of porous PTFE (inner diameter: 0.19 mm, outer diameter: 0.25 mm). A biosensing system was assembled with a syringe pump, a sample injection valve, an immobilized L-lysine a-oxidase column as a recognition element for L-lysine, the gas-diffusion device, and a flow-type fluorescent spectrophotometer. Standard L-lysine solutions (100 μl) were measured by monitoring variations in fluorescent intensity of OPA reagent. A linear relationship was obtained between the concentration of L-lysine (5.0 μM - 200 μM) and the change in fluorescent intensity.