boron and 1-naphthol-8-amino-3-6-disulfonic-acid

Boric acid reacts with 5-fluorosalicylaldehyde (F-SA) and 8-amino-1-naphthol-3,6-disulfonic acid (HA) to form the boric acid-fluoroazomethine H complex (F-AzB) that is now being used for the flow-injection analysis (FIA) of boric acid. At pH 6.5, the F-AzB complexation proceeded fairly fast, whereas the fluoroazomethine H (F-AzH) formation was slow. Thus, highly sensitive measurement of F-AzB was possible if the reaction time was controlled using the FIA method to decrease the background absorbance of F-AzH at the analytical wavelength. The optimum conditions for the color developing reaction were investigated for single and dual channel systems. The former system was simple, applicable to the determination of boron in reversed osmosis (RO) desalination water with a detection limit (LOD) of 4 μg B dm(-3). For the latter system, the calibration range was 0.005 to 10 mg B dm(-3) with an LOD of 1 μg B dm(-3), which can be applicable to natural water analyses of boron. These methods could analyze 15 - 20 samples in one hour. The results of the boron concentration measurement for water samples from an RO desalination plant, industrial wastewater and river water were in fairly good agreement with those obtained by other methods.

Topics: Aldehydes; Boric Acids; Boron; Flow Injection Analysis; Kinetics; Limit of Detection; Naphthalenesulfonates; Water Pollutants, Chemical

A new method for the highly sensitive and selective determination of boron at nanograms per cubic decimeter levels has been developed based on the derivatization reaction of boron using salicylaldehyde and 1-amino-8-naphtol-3,6-disulfonate with reversed-phase partition high-performance liquid chromatography. A detection limit as low as 2.0 nmol/dm(3) (22 ng/dm(3)) was achieved without any preconcentration. No significant interference was observed in the determination of 16 micromol/dm(3) of boron with the addition of nine metal ions (Al(III), Cu(II), Co(II), Fe(II), Fe(III), Ni(II), Mn(II), V(V), Zn(II)) at concentrations 100 times greater than that of boron without any masking procedure. The proposed method was successfully applied to the determination of boron in river water, tap water, doubly distilled water, and highly purified water.

Topics: Aldehydes; Aluminum; Boron; Chromatography, High Pressure Liquid; Metals, Heavy; Naphthalenesulfonates; Water; Water Supply