Cyclodextrin CSP

One of the latest resolutions of the anesthetic enflurane (8) has been performed by preparative GC on a y-cyclodextrin CSP, the process later being scaled-up via SMB [109] (Fig. 1-4). This is the first GC-SMB separation described. 

Comparisons of LC and SFC have also been performed on naphthylethylcar-bamoylated-(3-cyclodextrin CSPs. These multimodal CSPs can be used in conjunction with normal phase, reversed phase, and polar organic eluents. Discrete sets of chiral compounds tend to be resolved in each of the three mobile phase modes in LC. As demonstrated by Williams et al., separations obtained in each of the different mobile phase modes in LC could be replicated with a simple CO,-methanol eluent in SFC [54]. Separation of tropicamide enantiomers on a Cyclobond I SN CSP with a modified CO, eluent is illustrated in Fig. 12-4. An aqueous-organic mobile phase was required for enantioresolution of the same compound on the Cyclobond I SN CSP in LC. In this case, SFC offered a means of simplifying method development for the derivatized cyclodextrin CSPs. Higher resolution was also achieved in SFC. 

The mobile phases used with cyclodextrin CSPs are similar to those used in reverse phase chromatography, ie water or buffer solutions modified with methanol or acetonitrile. 

Ekgorg-Ott et al. (1997). An interesting trend was discovered when considering the relative amount of D-theanine present in the samples. The teas of the highest grades consistently contained the lowest amounts of D-theanine. The theanine achiral-chiral system configuration included a C18 column operated in the reverse-phase mode and a y-cyclodextrin CSP in the polar organic mode. 

Enantioseparation of nine amphetamine derivatives, methorphan, and propoxyphene was studied by comparing two different CSP typologies, a macrocyclic antibiotic CSP (vancomycin) and a native P-cyclodextrin CSP [123]. The suitability of the eluent systems to ESI interfacing was discussed, and a tandem mass spectrometric (MS/MS) detection method was developed. 

Chen, S. and Ward, T., Comparison of the chiral separation of amino-acid derivatives by a teicoplaiun and RN-fS-cyclodextrin CSPs using waterless mobile phases factors that enhance resolution. Chirality, 16, 318, 2004. 

CM-fi-CD Carboxymethyl-beta-cyclodextrin CSP Chiral stationary phase(s)... 

Cyclodextrin-CSP Broad Reversed phase, alcohols 0.1-3 Limited No... 

The flow chart shown in Fig. 12 presents a potential method development scheme for these cyclodextrin CSPs. It has been developed over the years Ifom a screening of many applications and is believed to be the best statistical approach to the successful use of these phases. The following outline addresses the key issues in developing and optimizing a separation ... 

---