Small Solute Analysis by CZE

Though originally conceived to be a method which would be well suited for bioploymers, CZE has proven to be very well suited for small solute analysis. Numerous examples of small solute analysis for CZE have been reported [11]. 

Using standard samples, Landers, et al. have shown the general utihty of the cis-diol-borate complex approach for a variety of small bioactive compovmds, such as hormone substances and nucleic acids [36]. Croft and Hinks did the analysis of a variety of classes of dyes by CZE [37]. 

Demonstrating the abihty of CE to do analysis in complex matrices, Liu and Sheu [38] have reported the separation of 8 quaternary alkaloids from Coptidis rhizoma which are commonly found in Chinese herbal remedies (Figxire 6). These investigators also determined ephedrine and pseudophedrine in Chinese herbal preparations [39]. Stuppner, et al. demonstrated the separation of 6 oxindole alkaloids from the root bark of Unicaria tomentosa [40]. 

Examples of using cyclodextrin modifiers for enhancement of separation has been shown by Baeyens, et al.[44] and Yeo, et al. [45]. The first group demonstrated the separation of pilocarpine and isopilocarpine in ophthalmic preparations, while the later demonstrated the separation of plant growth hormones. 

Chiral separations of small solutes are gaining wide spread attention. Terabe, et al. first suggested that the cyclodextrans could act as a pseudophase, much in the same way that the micelle is a pseudophase for micellar electrokinetic chromatography (MEKC) [46]. Novotny, et al. have recently given an overview of CE and MEKC methods for chiral analysis [47]. 

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