Isolation of compounds from complex sample mixtures for identification purposes — The semi-preparative separation of natural products

Summary

Semi-preparative separation and collection of compounds from complex mixtures by HPLC followed by identification of the isolated substances is a method combination which finds increasing interest in analytical laboratories. An analytical high-pressure liquid chromatograph has been enhanced with hardware that allows automatic, unattended, semi-preparative separation and fraction collection. The system is described and its practical applicability is demonstrated with the isolation of compounds from a natural product. Identification of collected sample was carried out using CI-MS, EI-MS, UV and NMR. The results show that the off-line combination of HPLC with other analytical techniques is a very powerful tool for identification purposes.