Catalytic fluorimetric determination of trace chromium VI based on the oxidation of pyronine Y by potassium bromate

A new catalytic fluorimetic method is proposed for the detemination of trace chromium?.The method is based on the catalytic oxidation of pyronine Y by potassium bromate in dilute phosphoric acid medium.The catalytic reaction,which is pseudo-zero-order,runs for 9 minin boiling water.The linear range of detemination is 5.0-100.0 g/L.The detection limit is 3.210~(-9) g/mL.The method has been applied to the determination of trace chromium? in environmental water samples,and the recoveries in the range of 96%102% are obtained.