Sample preparation and column regeneration in biopolymer separations

Successful use of high-performance liquid chromatography (HPLC) for biopolymer separations requires adequate sample preparation procedures for prefractionation of complex mixtures, solubilization of the compounds of interest, or removal of contaminants which would interfere with chromatography or damage the HPLC column. Rapid techniques have been described for solid-phase and liquid-liquid extraction, desalting, detergent removal, concentration, and filtration. A number of commercial products are available for off-line batch sample preparation and for on-line automated sample processing. These include ultracentrifugation cartridges and a wide variety of sorbents sold in bulk form or packed in disposable cartridges or minicolumns. In cases where HPLC column performance has degenerated to unacceptable levels, procedures have been described to achieve partial or complete recovery of performance. These include addition of material to fill voids caused by compaction or dissolution of the packing, replacement or cleaning of contaminated frits, regeneration of lost stationary phase material, and stripping of strongly retained contaminants from the stationary phase with suitable strong solvents.