Separation of positional isomers on a calix[4]arene-methylsiloxane polymeras stationary phase in capillary GC

Poly(p-tert-butyltrimethoxymonopropyloxycalix [4]arene-methylsiloxane) (TBC X-MS) has been prepared and used as a stationary phase in isothermal capill ary gas chromatographic separation of some positional isomers. Retention fa ctors (k) and separation factors (a) for the isomers were measured and comp ared with those on poly(p-tert-butyl-dimethoxydiprspyloxycalix[4]arene-tetr amethyldisiloxane) (TBCX-TMDS), poly(dimethoxy-dipropyloxycalix [4]arenetet ramethyl-disiloxane) (CX-TMDS). Most of the isomers investigated are well r esolved on TBCX-MS. Retention of all the compounds decreases on the three p hases in the order, TBCX-TMDS greater than or equal to TBCX-MS > CX-TMDS. S imilar retention values on TBCX-TMDS and TBCX-MS seem to indicate that rete ntion property of the two phases is not significantly affected by the spati al position of the calixarene moiety.