Personal overpressured-layer chromatography (OPLC) basic system 50, flexible tool in analytical and semipreparative work

A new automated overpressured-layer chromatographic (OPLC) system called th e Personal OPLC Basic System 50 is suitable for analytical and semipreparat ive separations. The automatic microprocessor-controlled system ensures rap id and reproducible off-line isocratic and stepwise gradient separations. H igh external pressure (5 MPa) makes the sorbent layer more homogeneous, yie lding more efficient off-line separation compared with those by early Chrom pres chambers. A theoretical plate height of 10-30 mu m can be achieved on an analytical high-performance thin-layer chromatographic (HPTLC) layer mad e of irregular silica gel with an average particle size of 5 mu m if an opt imal linear velocity (20-40 mm/min) and a nonviscous solvent system are use d, On an analytical layer of 3 mu m spherical silica gel, a theoretical pla te height of 6-15 mu m can be reached. Rapid analytical separations of resv eratrol (1555 s) and xanthine by one-(498 s) and two-directional (274 s) of f-line developments were accomplished. On-line separation and detection com bined with off-line sample application and fully on-line processing (includ ing on-line sample application, separation, and detection) were fulfilled w ith a TLC plate for xanthine separation. Semipreparative isolation of xanth ines was achieved through a fully on-line OPLC operating mode and scaled-up chromatography.