METHOD OF DETERMINATION OF CONTENT OF TOXIC ELEMENTS IN RAW MATERIAL AND SUGAR PRODUCT OF SUGAR PRODUCTION PROCESS

摘要

FIELD: production of sugar; check of quality of sugar product. ; SUBSTANCE: proposed method includes preparation of samples of each toxic element before measuring them by mineralization method, preparation of graduated solutions of each toxic element, measurement and determination of mass concentration of each toxic element by atomic absorption method through converting the liquid sample containing toxic element to monatomic state followed by photometric measurements of graduated solutions and solutions of samples to be checked for presence of toxic element, calculation of mass concentration of each toxic element, processing of results and check of their correctness. Each toxic element: arsenic, cadmium, copper, lead, zinc is determined together with determination of mass concentration of each element in sugar beet, beet pulp or molasses; mineralization of each sample at weight of 2.000-0.001 g is performed by evaporation of sample in presence of nitric acid at several stages depending on kind of sample. Prior to last evaporation stage, concentrated nitric acid in the amount of 5-10 cu cm is introduced into sample of sugar beet, beet pulp or molasses after which hydrogen peroxide or perchloric acid is added is the amount of 2-3 cu cm; then mixture is evaporated and upon completion of evaporation, mixture is subjected to boiling continued for 10-15 min. Graduated solutions of each toxic element prepared for performing quantitative measurement at concentration corresponding to linear measurement of concentration. Conversion of liquid sample of sugar beet, beet pulp of molasses to monatomic state is performed by electrothermal atomizing, after which optical density of atomic vapor of element under test is determined. ; EFFECT: unification of determination of all toxic elements; enhanced efficiency. ; 34 cl, 1 dwg, 2 tbl