Determination of boron in bottled drinking water of various mineralization
Authors
R. G. Sirotkin
Lobachevsky State University of Nizhny Novgorod
A.V. Knyazev
Lobachevsky State University of Nizhny Novgorod
E.V. Elipasheva
Lobachevsky State University of Nizhny Novgorod
A.E. Maslova
Lobachevsky State University of Nizhny Novgorod
Keywords:
tetrafluoroborate ions, boric acid, spectrophotometric determination, bottled drinking water
Abstract
The paper proposes a method for the photometric determination of boric acid in samples of bottled drinking water. Conversion of boron compounds into the form of tetrafluoroborate ions was carried out by keeping or ultrasonic irradiation. Two dyes of different classes (methylene blue and brilliant green) were considered as reagents. The metrological characteristics of both techniques were calculated. Six samples of therapeutic mineral water (“Bzhni”, “Essentuki No. 4”, “Essentuki No. 17”, “Zapovednik Zdorovya No. 17”, “Karmadon”, “Societe Minerale”) were selected for the study. The technique with the use of a brilliant green reagent and toluene as an extractant of the colored reaction product is most applicable in real conditions. Most of the micro- and macro-components of mineral waters did not interfere with evaluations. It was established that the boron content corresponds to the stated in the quality certificates in all selected samples. The concentration range was 0.01–1 mg/l in terms of boron. Limit of detection was 5∙10-3 mg/l
