The 2,3-di-O-methyl-, 2,3-di-O-ethyl-, and 2,3-di-O-acetyl- derivatives of 6-t-hexyldimethylsilyl-- and --cyclodextrins (THDMS-- and --CDs) were synthesized. The performance of columns prepared with these CD derivatives diluted in polysiloxanes with different polarity (PS-347.5, PS-086, and OV-1701) was evaluated with several series of racemates having different structures and volatilities. The results obtained with THDMS-- and --CDs were compared with those of the corresponding 6-O-t-butyldimethylsilyl-- and - derivatives (TBDMS-- and --CDs) to evaluate the influence on enantioselectivity of the substituent in position 6 of the sugar units of the two cyclodextrins. Columns prepared with both series of derivatives (THDMS- and TBDMS-- and --CDs) were evaluated by analyzing a series of high-to-medium volatility racemates and of medium-to-low volatility chiral pesticides. For high-to-medium volatility racemates, the TBDMS--CDs are the most enantioselective, while for medium-to-low volatility racemates the THDMS--CDs have a better enantioselectivity than the corresponding TBDMS--CDs.
Cyclodextrin derivatives in GC separation of racemates with different volatility - PART XV: 6-O-t-butyldimethylsilyl- vs. 6-O-t-hexyldimethylsilyl-ß- and -g-derivatives
BICCHI, Carlo;CRAVOTTO, Giancarlo;RUBIOLO, Patrizia;
1999-01-01
Abstract
The 2,3-di-O-methyl-, 2,3-di-O-ethyl-, and 2,3-di-O-acetyl- derivatives of 6-t-hexyldimethylsilyl-- and --cyclodextrins (THDMS-- and --CDs) were synthesized. The performance of columns prepared with these CD derivatives diluted in polysiloxanes with different polarity (PS-347.5, PS-086, and OV-1701) was evaluated with several series of racemates having different structures and volatilities. The results obtained with THDMS-- and --CDs were compared with those of the corresponding 6-O-t-butyldimethylsilyl-- and - derivatives (TBDMS-- and --CDs) to evaluate the influence on enantioselectivity of the substituent in position 6 of the sugar units of the two cyclodextrins. Columns prepared with both series of derivatives (THDMS- and TBDMS-- and --CDs) were evaluated by analyzing a series of high-to-medium volatility racemates and of medium-to-low volatility chiral pesticides. For high-to-medium volatility racemates, the TBDMS--CDs are the most enantioselective, while for medium-to-low volatility racemates the THDMS--CDs have a better enantioselectivity than the corresponding TBDMS--CDs.
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