Гідрокислоти та поліоли як потенційні екстрагенти для іонометричного визначення бору в грунтах.

Abstract

Boron is an essential element for plants, animals, and humans. Its deficiency in plants may result in reduced growth rates, yield loss, and even death. At the same time, excess of boron is toxic for both plants and living organisms. Boron is important for steroid hormones production, vitamin D and minerals metabolism, formation of bone tissue, and affects estrogen and testosterone levels. The primary source of boron for humans and other living organisms is plant-origin food. The richest ones are fruits and nuts. High concentrations of boron are found in raisins (22 mg/kg), peanuts (17 mg/kg), peanut butter (14,5 mg/kg). In the agriculture the boron monitoring in soils and water irrigation is particularly important because this element is crucial for plant growth Boron deficiency has a drastic effect on fruit quality and yield, even when there are only mild or moderate foliar symptoms. The main source of boron for plants is soil and water. Quantitative determination of boron in soil extracts can be performed using spectrophotometric, potentiometric, chromatographic, atomic absorption spectrophotometric, and inductively coupled plasma techniques. The most popular are inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). These methods are described in the appropriate standards PN-EN ISO 11885:2009 and PN-EN ISO 17294–1:2007. Boric acid is known to form complexes through esterification reactions with hydroxy-group in molecules of amino- and carboxylic acids, carbohydrates, nucleotides and vitamins that can be used for boron extraction from soils. Partial esterification results in monoesters (1:1 complex) and complete esterification leads to the bicyclic diester (1:2 complex). In present research the tetrafluoroborate selective sensor applicable for fluoroborate formation reaction monitoring was used as an analytical tool for the investigation of an impact of soil extraction procedure for boron analysis. The investigation of alternative soil boron extraction procedures using α- hydroxy acids (and other cis-diol containing compounds) and subsequent quantitative analysis of boron by kinetic-potentiometric monitoring of fluoroborate formation rate with use of previously developed [BF4]¯ -selective electrode have been performed. The kinetics of complex destruction under fluoride containing acidified media by means of kinetic-potentiometric analysis has been investigated. The possible boron losses during its extraction from soils have been checked.