A Spectrophotometric Method for Rapid Analysis of Chlorogenic Acid and Rutin in Tobacco / Eine spektrophotometrische Schnellmethode zur Bestimmung von Chlorogensäure und Rutin im Tabak

For the determination of chlorogenic acid in plant material a spectrophotometric method, which is based on a bathochromic shift of the absorption spectrum induced by boric acid, has been adapted for the use on tobacco by substituting aminoethyl diphenylborate for boric acid as the bathochromic agent. The sensitivity and accuracy of the method could thus be increased, and the method was rendered more versatile through the possibility of the simultaneous determination of rutin. In ground tobacco, this method enables the analyst to execute a complete determination of chlorogenic acid and rutin in 30 minutes; its simplicity renders it particularly useful for serial routine analyses. The method is accurate (99 percent at least of the present chlorogenic acid and rutin are determined), specific (excepted for air-cured tobacco) and precise (the absolute error of 95 out from 100 results is of ± 0.025 percent chlorogenic acid and ± 0.05 percent rutin), and it can be applied to fresh plant material as well as to cured tobacco. The determinations in several types of tobaccos show that isochlorogenic acid is present in measurable amounts only in Turkish tobacco (about 8 percent of the total chlorogenic acid). The polyphenolic fraction of Turkish and flue-cured tobaccos is composed almost entirely of chlorogenic acid and rutin, whereas the air-cured tobaccos, of low polyphenolic contents, contain proportionally large amounts of other polyphenolic compounds.