PREPARATION OF CYCLODEXTRIN PRECIPITATES WITH VOLATILE HYDROCARBONS IN AQUEOUS-MEDIA, AND DETERMINATION OF HYDROCARBON CYCLODEXTRIN MOLAR RATIOS IN THE PRECIPITATES

A technique is proposed to prepare cyclodextrin (CyD) precipitates with volatile hydrocarbons. On introducing the vapor of a liquid or solid hydrocarbon into alpha-, beta-, or gamma-CyD in an aqueous solution and circulating it in a closed system, CyD can be easily precipitated. The CyD precipitates isolated from aqueous solutions were analyzed for the hydrocarbon/CyD molar ratio. The concentration of CyD in the supernatant aqueous solution was also measured. The technique has been applied at 25-degrees-C to such hydrocarbons as n-alkanes (C5 to C10), cyclohexane, halobenzenes(fluoro-, chloro-, bromo-, and iodo-benzene), p-difluorobenzene, benzene, naphthalene, biphenyl, and diphenylmethane. Precipitates were also prepared in beta-CyD solutions with the vapor of C5-Cg mixtures at various mixing ratios.