Chiral WCOT columns

Chiral WCOT columns suitable for the enantiomeric separation of small molecules such as esters, ketones, alkanes and alcohols have recently been introduced. One example of a chiral column has a stationary phase film consisting of a non-bonded mid-polar, 35% phenyl 65% methyl siloxane modified by embedding in the film permethylated a- or /3-cyclodextrin. Elution characteristics are modified by the cyclodextrin content DEX 110 contains 10% cyclodextrin and DEX 120, 20% [127, 128]. 

Advances in the manufacture of flexible fused silica WCOT columns will almost certainly extend the applications of GC by virtue of their high-resolution capability, while the advent of sophisticated, computerized detectors forecast the improvement in sensitivity and specificity. The use of chiral stationary phases for the resolution of enantiomers is becoming an increasingly important topic in pharmaceutical analyses. The range and availability of various liquid phases for chiral analysis by GC is bound to make this technique extremely valuable for the assay of pharmaceutical raw materials as well as for use in biological fluids. 

The catalyst testing was carried out in a gas phase downflow stainless steel tubular reactor with on-line gas analysis using a Model 5890 Hewlett-Packard gas chromatograph (GC) equipped with heated in-line automated Valeo sampling valves and a CP-sD 5 or CP-sil 13 capillary WCOT colunm. GC/MS analyses of condensable products, especially with respect to O-isotopic distribution, was also carried out using a CP-sil 13 capillary column. For analysis of chiral compounds, a Chirasil-CD capillary fused silica column was employed. 

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