Reverse Flow Injection Analysis for Determination of Manganese(II) in Natural Water

Abstract

A simple, rapid and sensitive reverse flow injection analysis (rFIA) method fordetermining the concentration of manganese in natural water has been developed. Theanalytical method is based on the reaction between Mn(II) and 4-(2-pyridylazo)resorcinol,which can be spectrophotometrically monitored at 495 nm. The chemical and flow injectionvariables were studied and optimized to make the procedure suitable for quantitatingMn(II) in water samples. The linear calibration curve is obtained in the range of 0.05-1.0 mgL-1 Mn (II) with r2 = 0.9993. The method has detection limit of 0.034 mg L-1 and is capableof a sampling frequency of 180 h-1. The rFIA method provided good sensitivity and precisionfor determination of Mn(II) with a relative standard deviation of 0.8%. The procedure wasapplied successfully to the determination of Mn(II) in natural water, and the results weresatistically compared with results determined by atomic absorption spectrometric method.