Page 223 - Chiral Separation Techniques

7.3 Conclusion 201

Fig. 7-18. Type V: Reactive separation.

Fig. 7-19. Enzymatic resolution and separation of ibuprofen sulphonmethyl ester.

arated chromatographically. Integration of the reaction and the separation may be
performed in a chromatographic reactor and, by applying the principle of SMB chro-
matography, a continuous reaction/separation system can be set up [34]. Today, a
wide variety of enzymes is known which can convert different derivatives specifi-
cally, with sufficient yield and in short time, so that they may be used in a chro-
matographic reactor.

7.3 Conclusions

Although indirect chiral separation seems to be a less elegant method than direct sepa-
ration on CSPs, the importance of the flexibility and broad applicability of these deriva-
tization methods cannot be overestimated. While direct methods will either work or not
– and are subject to only minimal influence by the operator – derivatization methods
offer a wide range of different methodologies, with a guaranteed success. On the basis
of this general approach – which may be applied to entire groups of compounds – rules
may be deduced from the literature. Therefore, this arsenal of indirect separation meth-
ods should be borne in mind and investigated thoroughly in order to determine the
optimum solution for any given problem involving separation.