THEORY AND PRACTICE OF RAPID FLOW-THROUGH ANALYSIS BASED ON OPTODE DETECTION AND ITS APPLICATION TO PH MEASUREMENT AS A MODEL CASE

Rapid now-through analysis (RFA) based on optode (optical chemical sen sor) detection is proposed, and its performance is discussed using the RFA system equipped with a pH-sensitive optode as a model case. To de monstrate and understand the usefulness of the RFA system, long-lifeti me pH-sensitive optodes were prepared casing a hydrophilic poly(hydrox yethyl methacrylate) (poly-HEMA) membrane covalently immobilized with a dye containing an amino group such as Congo Red or Nile Blue. The re sponse equation for the optode with the RFA system was proposed, and s atisfactory estimation for rapid pH analysis was obtained. The propose d RFA can stand as an advanced method for conventional now injection a nalysis.