Determination of Cifric Acid in the Presence of Interfer- ing Substances.-It is usually necessary to estimate citric acid in the presence of one or more Krebs cycle intermedi- ates. The substances which yield COS when oxidized with ceric sulfate are or-ketoglutaric acid, pyruvic acid, oxalacetic acid, and, to some extent, malic acid. (All of the corn- pounds mentioned, with the exception of malic acid, could actually be determined with ceric sulfate. For each mole of ...
