METHOD FOR DEFINITION OF CAFFEINE CONTENT IN TEA AND COFFEE

摘要

FIELD: food industry.;SUBSTANCE: method for definition of caffeine content includes caffeine preliminarily removal from the extraction base by chloroform with subsequent extract evaporation to produce a dry residue, the dry residue dissolution in hydrochloric acid, quantitative definition of analysable substance in the prepared sample. Quantitative definition of analysable substance is performed by way of placing the prepared sample into a cell containing photogenerated iodine in the presence of a sensibilisator mixture, registering iodine quantity reduction which is performed amperometrically by variation of intensity of current in the cell with subsequent absorbing solution light radiation till replenishment of iodine loss and definition of caffeine content by variation of intensity of current in the cell and time of iodine generation in the cell.;EFFECT: definition selectivity and sensibility improvement.;2 dwg, 3 tbl, 2 ex