Flow Injection Spectrophotometric Determination of Ferbam Based on a Photochemical Reaction

Abstract.

 A flow-injection configuration for the spectrophotometric determination of ferbam is proposed. The procedure is based on the “online” decomposition of ferbam and complexation of the released Fe³⁺ with oxalate. The ferrioxalate formed is decomposed upon irradiation with visible light. The Fe²⁺ produced in the photochemical reaction was monitored by measuring the absorbance after complexation with ferrozine (λ_max=562 nm). The method shows a linear range between 1.0 and 30 µg mL⁻¹ (2.5×10⁻⁶−7.2 × 10⁻⁵ mol L⁻¹) with a limit of detection of 0.2 µg mL⁻¹. Repeatibility was 0.53% expressed as relative standard deviation (n=10), and reproducibility, studied on five different days, was ±1.23%. The sampling frequency was about 45 samples h⁻¹. The applicability of the method was tested in the determination of ferbam in waters and grains.