A new method for the rapid and precise determination of chlorogenic acid in green and roasted coffee is based upon the absorption of chlorogenic acid at 324 millimicrons.The chlorogenic acid is extracted from flaked coffee samples with water, and for green coffee the ultraviolet absorption is measured directly on the extract.

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Rapid and accurate methods for the determination of theobromine and caffeine in cacao materials have been developed. The theobromine and caffeine are extracted from the plant materials by percolation with hot water in the presence of magnesium oxide, and the extract is clarified by treatment with zinc acetate-potassium ferrocyanide reagents.The alkaloids in the clarified extract are adsorbed on a column of English XL fuller's earth and the theobromine is selectively eluted with dilute sodium hydroxide. The alkaline solution is adjusted to pH