A flow injection analysis (FIA) for boron determination was studied using a compact and simple two-channel manifold. This method is based on the chromogenic reaction of borate with azomethine-H to form a yellow complex. The absorbance of the complex was measured at 405 nm. The chemical factors and FIA variables influencing the color development were examined. When a 0.5% (w/v) azomethine-H solution (pH 6.5) containing 1.5 % (w/v) ascorbic acid and 10 % (w/v) ammonium acetate was used as a reagent solution, the constant and maximum absorbance was obtained at a flow rate of 1.2 mL min
-1 and a reaction temperature of 40 °C. Under optimum conditions with 200 μL sample injection, the calibration graph was linear from 0.01 to 1.2 mg L
-1 of boron. The relative standard deviation was 0.99 % (n = 9) at the 0.2 mg L
-1 level. The detection limit and the determination limit were 0.011 (3σ) and 0.037 (10σ) mg L
-1, respectively. The sampling rate was 20 h
-1. The proposed FIA promises a simple and rapid method with high sensibility and precision for boron determination in aqueous samples.
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