UNIGE document Scientific Article
previous document  unige:1710  next document
add to browser collection
Title

Some solutions to obtain very efficient separations in isocratic and gradient modes using small particles size and ultra-high pressure

Authors
Published in Journal of Chromatography. A. 2009, vol. 1216, p. 32332-3243
Abstract The UHPLC strategy which combines sub-2 μm porous particles and ultra-high pressure (>1000 bar) was investigated considering very high resolution criteria in both isocratic and gradient modes, with mobile phase temperatures between 30 and 90 °C. In isocratic mode, experimental conditions to reach the maximal efficiency were determined using the kinetic plot representation for ΔPmax = 1000 bar. It has been first confirmed that the molecular weight of the compounds (MW) was a critical parameter which should be considered in the construction of such curves. With a MW around 1000 g mol−1, efficiencies as high as 300,000 plates could be theoretically attained using UHPLC at 30 °C. By limiting the column length to 450 mm, the maximal plate count was around 100,000. In gradient mode, the longest column does not provide the maximal peak capacity for a given analysis time in UHPLC. This was attributed to the fact that peak capacity is not only related to the plate number but also to column dead time. Therefore, a compromise should be found and a 150 mm column should be preferentially selected for gradient lengths up to 60 min at 30 °C, while the columns coupled in series (3× 150 mm) were attractive only for tgrad > 250 min. Compared to 30 °C, peak capacities were increased by about 20–30% for a constant gradient length at 90 °C and gradient time decreased by 2-fold for an identical peak capacity.
Keywords UPLCUHPLCHTLCTemperatureGradientPeak capacityVery high resolution
Identifiers
Full text
Structures
Citation
(ISO format)
GUILLARME, Davy et al. Some solutions to obtain very efficient separations in isocratic and gradient modes using small particles size and ultra-high pressure. In: Journal of Chromatography. A, 2009, vol. 1216, p. 32332-3243. https://archive-ouverte.unige.ch/unige:1710

230 hits

1 download

Update

Deposited on : 2009-05-26

Export document
Format :
Citation style :