SOME SPECIFIC PROBLEMS IN THE PRACTICE OF PREPARATIVE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The practice of preparative high-performance liquid chromatography (PLC) is reviewed. Special attention is paid to problems with the use of this method in research and development which are insignificant or unfamiliar on an analytical scale. PLC column concepts, stability and related packing procedures are discussed. Guidelines to column size selection and optimum use are presented. The paramount importance of high resolution for successful PLC separation is stressed and the effect of friction heat generated by viscous flow on the column performance is described. The significance of sufficient sample solubility in the mobile phase is discussed. Possible deleterious effects of the use of strong solvents with viscosities different from that of the mobile phase are considered. The packing solubility is shown to influence product purity; various product isolation procedures are discussed and the use of solid-phase extraction is recommended.