USE OF ESTERIFIED AND UNESTERIFIED DIPENTYLATED GAMMA-CYCLODEXTRIN, BETA-CYCLODEXTRIN AND ALPHA-CYCLODEXTRIN AS GAS-CHROMATOGRAPHIC STATIONARY PHASES TO INDICATE THE STRUCTURE OF MONOTERPENOID CONSTITUENTS OF VOLATILE OILS

''Chiraldex-G-DA'', unesterified dipentylated gamma-cyclodextrin, yields a twenty-nine solute sequence distinctively different to other cyclodextrin modifications and to conventional stationary phases, particularly retaining bicyclic molecules. Percentage increases in relative retention times to n-undecane from the alpha-cyclodextrin corresponding phase are very indicative of solute structure: acyclics less than 60%, bicyclics over 150%, with monocyclics between. Percentage increases are also discussed from alpha- to gamma-ester dipentylated cyclodextrins; from unesterified to esterified ''G-PN'' gamma-phases; and between the two beta-phases. With the lattermost pair, carbonyl solutes show increased values on the beta-ester ''B-TA'' if not bicyclic, whilst alcohols increase on the unesterified phase except for some acyclics. Plots of values for some solutes on the three phases (both the esterified and unesterified) suggest that only sometimes may inclusion complexing be involved with the cyclodextrin rings -usually the largest. A solute is likely to have a different pattern on the esterified phases.