Mathematical equations are derived in order to predict, with the knowledge of the RF values of six aldohexose (or aldomethylose) sugars, the Rp values of the remaining two. The aldohexose and aldomethylose sugars are treated separately.
ARM values and vicinal correction factors were calculated for the hydroxyl groups at C-2, C-3 and C-4, using the Rp values given by ISHERWOOD AND JERMYN~. A self-consistent set of constants was obtained, which gives good agreement between the experimental and calculated RM values for all the cases in which data were available in the literature.
Several studies have been devoted to the correlation of the structure of sugars and their chromatographic behaviour 1-s. In the case of aldohexose and aldomethylose sugars, a quantitative correlation between the steric positions of the hydroxyl groups and the RF values of the sugars has not been established as far as we know.
Such a correlation may be helpful in the identification of some of the sugars which are not easily obtainable and may be interesting from a theoretical point of view.
TNEORETICALCONSIDERATIONS
The present state of knowledge related to MARTIN'S additivity principle can be summarized as follows according to LEDERER AND PIRELLIO: "The additivity of d1p~ values should not be entirely rejected as unreliable, but it should be born in mind that certain solvents obey this rule while others do not".
BUSHES has given an extensive review of the
Rns theory and its applications. Early and recent examples of the application of the theory are also given in refs. 11-13.
These authors have pointed out that there'are two main sources of difficulty in applying the theory, and BUSH 10 has emphasized that these must be distinguished carefully. In the first place many substances contain substituents which interact with one another and do not fulfil the premises of MARTIN'S~~ original theory. Secondly, many sources of experimental error have not been adequately controlled by authors claiming to have invalidated the theory0~10~13.