Objective: A new fluorimetric method is proposed for the determination of As(Ⅲ).Methods:The method is based on the inhibitory effect of As(Ⅲ) on the oxidation of Acridine Red(ADR) by potassium bromate in sulphuric acid medium,which resulted in the enhance of intensity of fluorescence.Results:The linear range was 0.0150.450 μg/ml with the detection limit of 2.1 μg/L.The RSD was less than 4.68% and the recoveries range 90.0%107.2%.Conclusion:The method can be applied to the determination of tr...