Studies on the long-term thermal stability of particulate and monolithic poly(styrene-divinylbenzene) capillaries in reversed-phase liquid chromatography

Abstract

In the present study, the long-term high-temperature (>80 degrees C) and temperature programming stability of fused silica capillaries packed with 5 microm PLRP-S 300 A and monolithic PS-DVB capillaries (both 180 microm id x 6 cm) under reversed-phase conditions has been examined. In isothermal mode, the columns were defined as temperature-stable when a less than 10% change in apparent retention factors (k) and a less than 20% change in "retention time/peak width"-factors (n) of the probe solutes (proteins) were observed after passing 7,500 void volumes of effluent through the columns (about 100 h operation). According to these criteria, the PLRP-S and monolithic capillaries were defined temperature-stable at 100 and 130 degrees C, respectively. Furthermore, when continuously running temperature programs between 50 degrees C and the upper temperature limit determined in isothermal mode, virtually no change in k or n were observed on neither of the columns after running more than 35,000 void volumes or 1,600 temperature programs. Additionally, temperature-programmed reversed-phase separations of proteins on both types of capillaries are demonstrated and discussed.

Stability and repeatability of capillary columns based on porous monoliths of poly(butyl methacrylate-co-ethylene dimethacrylate)

“…To date, and despite the enormous significance for users, only a few studies related to the stability and repeatability of monolithic columns are found in the literature [18,25,26]. The most comprehensive study was published in 2002 by Kele and Guiochon [27].…”

High temperature liquid chromatography with monolithic capillary columns and pure watereluent

“…2 for the first time. This also represents a significant improvement on previous work using polymer monoliths with hydroorganic eluent which used a maximum temperature of only 140 C. 12 The long term stability of the capillary columns used in this study was investigated by subjecting the column to approximately 1000 column volumes ($30 hours) of continuous operation at 220 C. Comparison of chromatograms obtained before and after the 1000 column volumes of continuous operation (Fig. 2) highlights the stability and maintained performance of the column under high temperature conditions.…”