DETERMINATION OF ENANTIOMERIC PURITY OF MANDELONITRILE WITH DERIVATIZED CYCLODEXTRINS IN WATER

A variety of derivatized cyclodextrins was used for the determination of the optical purity of mandelonitrile by H-1-NMR (nuclear magnetic r esonance) spectroscopy in aqueous solution. Mandelonitrile was formed by the enzymatic reaction of benzaldehyde and HCN (or acetone cyanohyd rine) with the hydroxynitrile lyase (Hnl) from Hevea Brasiliensis (rub ber tree). It turned out the the best separation was achieved with ace tyl-beta-cyclodextrin (K-d=12 dm(3) mol(-1)). A straightforward integr ation was possible if there was more than 5% of one of the enantiomers in the solution. Below this value, the results were not reproducible enough for quantitative analysis.