To develop the experimental conditions for the determination of nanogram amounts of several ions and oxalic acid based on their catalytic effect on the oxidation of oxazine dyes such as Celestine blue Gallamine Blue, Gallocyanin and Brilliant Cresyl Blue by appropriate oxidizing agents. Preparing optodes by immobilizing above mentioned dyes in triacetyl cellulose membrane to detect and determine trace quantities of the above-mentioned species having catalytic activity.