Use of Cyclodextrins in Electrophoretic Techniques0.3(115(-)(+I0.15MASEEP(-)(+I2a l40.001gL:0 -z -m-0.15-0.300I510152025305time (midFigure 5.30 Electrophemgram of the chiml separation of a mixture of compounds under the best conditions found for methamphetamine (MA) and .selegiline (SE). Ephedrine @F) was not resolved in this run. Run conditions; Tris-phosphate bufler @H 2.5; 0.1 M) with EF-p-CD (200 mgmL-'); T = 20 "C (Reprinted with permission from 108)A neutral /I-CD polymer (EP-p-CD) successfully separated the enantiomers of selegiline, methamphetamine and ephedrine.lo* Because of the good enantioselectivity the method was proposed for the determination of the chiral purity of methamphetamine, selegiline and ephedrine. The chiral metabolite of the antipsychotic drug haloperidol was separated by using CDs as chiral selectors.'Og It was found that the type and concentration of CD in the electrolyte markedly influenced the enantioselectivity of the system and better separation was achieved at 2.5 than at 4.5 pH. DM-#I-CD has also been applied as chiral selector for the enantiomeric separation of phenylalkylamine derivatives (Figure 5.3 1 ) . I 1 O The running buffer consisted of 20 mM tris-phosphate (PH 2.7) containing 0.5% hydroxypropylmethyl cellulose and various concentrations of DM-p-CD. The electrophoretic mobility of drugs decreased in the presence of DM-/I-CD, the effect depending on the chemical structure of the individual drugs. Binding constants were considerably lower in the presence of 10 and 20% methanol and the optimal concentration of DM-P-CD increased accordingly. It was stated that this simple and rapid CE method can be employed not only for the chiral separation of phenylalkylamine enantiomers but also for the determination of binding constants, facilitating the calculation of the optimal concentration of chiral selector. A wide variety of other CE methods have been developed and employed for the chiral separation of amphetamine and related compounds. Thus, the chiral
