A sensory granular material based on impregnated composite «cross-linked polyvinyl alcohol – magnetite» for the determination of carbohydrates by optical micrometry

Abstract

Synthesis and application of a composite material «cross-linked polyvinyl alcohol (PVA) – magnetite» as a sensitive element for the determination of carbohydrates by optical micrometry has been studied. The chemical structure was confirmed by IR-spectroscopy. The content of Fe3O4 in PVA granules was calculated using magnetization curves. It is shown that the introduction of Fe3O4 particles into PVA granules at pH value of buffer solution 6.8 significantly narrows the range of carbohydrate concentrations to be determined and reduces the sensitivity of PVA to them. However, at pH 8.6 the presence of Fe3O4 particles in granules does not affect the metrological characteristics of the glucose and fructose determination (their detection limit equals 7.9 mmol/dm3) but reduces the relative standard deviation of their determination to 3 wt.%. Sensory granules with optimal magnetite content (1.54%) were tested in the determination of total content of glucose and fructose in natural syrups with a high level of fructose by optical micrometry. The results obtained match the accepted reference values specified by the syrup manufacturers.