Gas chromatographic enantiomer separation of atropisomeric PCBs using modified cyclodextrins as chiral phases

Citation
J. Magnusson et al., Gas chromatographic enantiomer separation of atropisomeric PCBs using modified cyclodextrins as chiral phases, HRC-J HIGH, 23(11), 2000, pp. 619-627
Citations number
51
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences
Journal title
HRC-JOURNAL OF HIGH RESOLUTION CHROMATOGRAPHY
ISSN journal
09356304 → ACNP
Volume
23
Issue
11
Year of publication
2000
Pages
619 - 627
Database
ISI
SICI code
0935-6304(200011)23:11<619:GCESOA>2.0.ZU;2-R
Abstract
Columns containing different types of cyclodextrin derivatives have been ev aluated for chiral gas chromatographic separation of atropisomeric PCBs, o, p'-DDT and o,p'-DDD. Separation was attempted on columns containing mixed c hiral selectors, and the performance of two closely related selectors was a lso examined. The cyclodextrins were: permethylated-beta -CD (PM-beta -CD), heptakis(2,3-di-O-methyl-6-O-tert-butyldimethylsilyl)-beta -CD (2,3-M-6-TB DMS-beta -CD), heptakis(2,3-di-O-methyl-6-O-tert-hexyldimethylisilyl)-beta -CD (2,3-M-6-THDMS-beta -CD), and heptakis(2,3-di-O-ethyl-6-O-tert-hexyldim ethylsilyl)-beta -cyctodextrin (2,3-E-6-THDMS-beta -CD). The cyclodextrins were dissolved in OV-1701 or in a dimethylsiloxane/silarylene copolymer con taining 5% phenyl in the backbone, The application of mixed chiral selector s led to improved separations, however; at most eleven PCB congeners were s eparated on a single column. Chiral resolution of o,p'-DDD was achieved. Th e use of a dimethylsiloxane/silarylene copolymer as a matrix for the cyclod extrins is a promising approach. With such a matrix, blocking of the CD cav ities by silicone substituent groups can be avoided, and a reasonable CD so lubility can be provided. The selectivity of heptakis(2,3-di-O-ethyl-6-O-te rt-hexyldimethylsilyl)-beta -CD and heptakis(2,3-di-O-methyl-6-O-tert-hexyl dimethylsilyl)-beta -CD was quite different, the former selector could sepa rate four congeners, while the latter separated ten congeners.