6533b854fe1ef96bd12ae756

RESEARCH PRODUCT

Study on the efficiency of assembled packed microbore columns in HPLC

subject

description

Stainless steel columns (internally mirror-finished, 125 or 250nm in length, of bore 1.0 or 1.6mm) were slurry-packed with 5µm and 4µm reversed phase silicas (Hypersil ODS, LiChrosorb RP-8 and RP-18 and Superspher RP-8. The HPLC equipment consisted of a pump LC5A (Shimadzu) or a pump 2150 (LKB Instruments), a rheodyne valve 7413 with loops of 0.5, 1.0 and 5.0mm3 and a Jasco-Uvidec 100-II UV detector, variously with one of three specially constructed cells of 0.2, 0.4 and 1.3mm3 volume. Columns were assembled using two types of coupling device employing a stainless steel capillary of 0.12mm bore. The effect of sample volume, design of coupling device in assembled column, detector cell volume and geometry on column plate count was examined to optimize the conditions and the instrument compartments. The highest efficiency for the assembled columns was achieved by use of the 0.2mm3 detector cell, a low dead volume coupling device and a 0.5µl sample volume. Sets of 5 assembled columns gave reduced plate height values between 2–3 at a reduced velocity 2<v<3, indicating that extra-column effects were negligibly small; the performance was identical to that of conventional analytical columns.