Performance of octadecylsilylated monolithic silica capillary columns of 530 μm inner diameter in HPLC

Abstract

Monolithic silica capillary columns were successfully prepared in a fused silica capillary of 530 microm inner diameter and evaluated in HPLC after octadecylsilylation (ODS). Their efficiency and permeability were compared with those of columns pakked with 5-microm and 3-microm ODS-silica particles. The monolithic silica columns having different domain sizes (combined size of through-pore and skeleton) showed 2.5-4.0-times higher permeability (K= 5.2-8.4 x 10(-14) m2) than capillary columns packed with 3-mm particles, while giving similar column efficiency. The monolithic silica capillary columns gave a plate height of about 11-13 microm, or 11 200-13 400 theoretical plates/150 mm column length, in 80% methanol at a linear mobile phase velocity of 1.0 mm/s. The monolithic column having a smaller domain size showed higher column efficiency and higher pressure drop, although the monolithic column with a larger domain size showed better overall column performance, or smaller separation impedance (E value). The larger-diameter (530 microm id) monolithic silica capillary column afforded a good peak shape in gradient elution of proteins at a flow rate of up to 100 microL/min and an injection volume of up to 10 microL.

Developments in ion chromatography using monolithic columns

“…Regardless of the monolithic media used, monoliths show better mass transfer at higher flow rates than particulate columns, while maintaining high efficiency [40]. Additionally, monoliths do not produce, at high flow rates, as large back pressures as typically seen with particle-based systems [41]. Being able to use faster flow rates with only small losses in efficiency could allow monoliths to be used for "fast IC" which has the potential benefits of fast method development and high sample throughput [11].…”

Recent development of monolithic materials as matrices in microcolumn separation systems

“…Motokawa et al [62] prepared silica-based monolithic RP-HPLC columns of 530 lm id. The column efficiency and permeability were compared with those of columns packed with ODS-silica particles and it was found that the domain sizes of the former differed from those of the latter, but the column efficiency was similar to that of a column packed with 3-lm particles.…”

Advances in monolithic silica columns for high-performance liquid chromatography

“…Ishizuka et al determined that efficiency of the columns increases with a decrease in the internal diameter of the column and made a column with an internal diameter of 75 μm Motokawa et al 2002). Later, columns with a higher internal diameter of 200 and 530 μm were made (Hara, Kobayashi, Ikegami, Nakanishi, and Tanaka, 2006;Motokawa, Ohira, Minakuchi, Nakanishi, and Tanaka, 2006).…”