All Outputs (50)

Comparison of peak shape in hydrophilic interaction chromatography using acidic salt buffers and simple acid solutions (2014)
Journal Article
Heaton, J. C., Russell, J. J., Underwood, T., Boughtflower, R., & McCalley, D. V. (2014). Comparison of peak shape in hydrophilic interaction chromatography using acidic salt buffers and simple acid solutions. Journal of Chromatography A, 1347, 39-48. https://doi.org/10.1016/j.chroma.2014.04.026

The retention and peak shape of neutral, basic and acidic solutes was studied on hydrophilic interaction chromatography (HILIC) stationary phases that showed both strong and weak ionic retention characteristics, using aqueous-acetonitrile mobile phas... Read More about Comparison of peak shape in hydrophilic interaction chromatography using acidic salt buffers and simple acid solutions.

Comparison of the kinetic performance and retentivity of sub-2μm core-shell, hybrid and conventional bare silica phases in hydrophilic interaction chromatography (2014)
Journal Article
Heaton, J. C., & McCalley, D. V. (2014). Comparison of the kinetic performance and retentivity of sub-2μm core-shell, hybrid and conventional bare silica phases in hydrophilic interaction chromatography. Journal of Chromatography A, 1371, 106-116. https://doi.org/10.1016/j.chroma.2014.10.013

© 2014 Elsevier B.V. The separation performance and retention properties of four sub-2μm underivatised silica materials were evaluated in the hydrophilic interaction chromatography (HILIC) mode. These included an organic/inorganic hybrid silica, conv... Read More about Comparison of the kinetic performance and retentivity of sub-2μm core-shell, hybrid and conventional bare silica phases in hydrophilic interaction chromatography.

Practical observations on the performance of bare silica in hydrophilic interaction compared with C18 reversed-phase liquid chromatography (2013)
Journal Article
Heaton, J. C., Wang, X., Barber, W. E., Buckenmaier, S. M., & McCalley, D. V. (2014). Practical observations on the performance of bare silica in hydrophilic interaction compared with C18 reversed-phase liquid chromatography. Journal of Chromatography A, 1328, 7-15. https://doi.org/10.1016/j.chroma.2013.12.058

The kinetic performance of a bare silica and C18 phase prepared from the same sub-2. μm and 3.5. μm base materials were compared in the HILIC and RP mode using both charged and neutral solutes. The HILIC column was characterised using the neutral sol... Read More about Practical observations on the performance of bare silica in hydrophilic interaction compared with C18 reversed-phase liquid chromatography.

Influence of phase type and solute structure on changes in retention with pressure in reversed-phase high performance liquid chromatography (2013)
Journal Article
Fallas, M. M., Tanaka, N., Buckenmaier, S. M., & McCalley, D. V. (2013). Influence of phase type and solute structure on changes in retention with pressure in reversed-phase high performance liquid chromatography. Journal of Chromatography A, 1297, 37-45. https://doi.org/10.1016/j.chroma.2013.04.006

The influence of pressure on the retention of several types of solute, including acids, bases and neutrals, was studied by the use of restriction capillaries added to the end of various monomeric and polymeric octadecylsilyl-modified 5. μm particle s... Read More about Influence of phase type and solute structure on changes in retention with pressure in reversed-phase high performance liquid chromatography.

Practical investigation of the factors that affect the selectivity in hydrophilic interaction chromatography (2013)
Journal Article
Kumar, A., Heaton, J. C., & McCalley, D. V. (2013). Practical investigation of the factors that affect the selectivity in hydrophilic interaction chromatography. Journal of Chromatography A, 1276, 33-46. https://doi.org/10.1016/j.chroma.2012.12.037

Retention data for a series of 29 compounds comprising acids, bases and neutrals were obtained on six different hydrophilic interaction (HILIC) columns including bare silica, zwitterionic and those bonded with neutral bonded ligands. The principal ai... Read More about Practical investigation of the factors that affect the selectivity in hydrophilic interaction chromatography.

The effect of pressure and mobile phase velocity on the retention properties of small analytes and large biomolecules in ultra-high pressure liquid chromatography (2012)
Journal Article
Fekete, S., Veuthey, J. L., McCalley, D. V., & Guillarme, D. (2012). The effect of pressure and mobile phase velocity on the retention properties of small analytes and large biomolecules in ultra-high pressure liquid chromatography. Journal of Chromatography A, 1270, 127-138. https://doi.org/10.1016/j.chroma.2012.10.056

A possible complication of ultra-high pressure liquid chromatography (UHPLC) is related to the effect of pressure and mobile phase velocity on the retention properties of the analytes. In the present work, numerous model compounds have been selected... Read More about The effect of pressure and mobile phase velocity on the retention properties of small analytes and large biomolecules in ultra-high pressure liquid chromatography.

A comparison of overload behaviour for some sub 2μm totally porous and sub 3μm shell particle columns with ionised solutes (2012)
Journal Article
Buckenmaier, S. M. C., Fallas, M. M., & McCalley, D. V. (2012). A comparison of overload behaviour for some sub 2μm totally porous and sub 3μm shell particle columns with ionised solutes. Journal of Chromatography A, 1235, 49-59. https://doi.org/10.1016/j.chroma.2012.02.027

The overloading performance of some 2.7 μm shell and sub 2 μm totally porous columns, including one pair manufactured from similar materials with similar bonding chemistries, was compared using strongly acidic and basic probe compounds. In general, t... Read More about A comparison of overload behaviour for some sub 2μm totally porous and sub 3μm shell particle columns with ionised solutes.

Contributions to reversed-phase column selectivity. II. Cation exchange (2011)
Journal Article
Marchand, D. H., Carr, P. W., McCalley, D. V., Neue, U. D., Dolan, J. W., & Snyder, L. R. (2011). Contributions to reversed-phase column selectivity. II. Cation exchange. Journal of Chromatography A, 1218(40), 7110-7129. https://doi.org/10.1016/j.chroma.2011.07.085

The contribution of cation exchange to solute retention for type-B alkylsilica columns (made from high-purity silica) has been examined in terms of the hydrophobic-subtraction (H-S) model of reversed-phase column selectivity. The relative importance... Read More about Contributions to reversed-phase column selectivity. II. Cation exchange.

Determination of catecholamines in urine using hydrophilic interaction chromatography with electrochemical detection (2011)
Journal Article
Kumar, A., Hart, J. P., & McCalley, D. V. (2011). Determination of catecholamines in urine using hydrophilic interaction chromatography with electrochemical detection. Journal of Chromatography A, 1218(25), 3854-3861. https://doi.org/10.1016/j.chroma.2011.04.034

The determination of catecholamines in urine was investigated using hydrophilic interaction chromatography (HILIC) as an alternative to the commonly used reversed-phase (RP) method. A number of different approaches were explored, including per-aqueou... Read More about Determination of catecholamines in urine using hydrophilic interaction chromatography with electrochemical detection.

Some practical comparisons of the efficiency and overloading behaviour of sub-2μm porous and sub-3μm shell particles in reversed-phase liquid chromatography (2011)
Journal Article
Mccalley, D. V. (2011). Some practical comparisons of the efficiency and overloading behaviour of sub-2μm porous and sub-3μm shell particles in reversed-phase liquid chromatography. Journal of Chromatography A, 1218(20), 2887-2897. https://doi.org/10.1016/j.chroma.2011.02.068

At their optimum flow, sub-3 μm superficially porous or " shell" particles demonstrate similar efficiency to sub-2 μm totally porous particles. The performance of 0.21. cm i.d shell columns is however inferior to those of 0.46. cm i.d., presumably du... Read More about Some practical comparisons of the efficiency and overloading behaviour of sub-2μm porous and sub-3μm shell particles in reversed-phase liquid chromatography.

A systematic investigation of the effect of sample diluent on peak shape in hydrophilic interaction liquid chromatography (2010)
Journal Article
Ruta, J., Rudaz, S., McCalley, D. V., Veuthey, J. L., & Guillarme, D. (2010). A systematic investigation of the effect of sample diluent on peak shape in hydrophilic interaction liquid chromatography. Journal of Chromatography A, 1217(52), 8230-8240. https://doi.org/10.1016/j.chroma.2010.10.106

The aim of this study was to evaluate the importance of sample diluents to improve peak shapes in hydrophilic interaction liquid chromatography (HILIC), using low molecular weight (

Instrumental considerations for the effective operation of short, highly efficient fused-core columns. Investigation of performance at high flow rates and elevated temperatures (2010)
Journal Article
McCalley, D. V. (2010). Instrumental considerations for the effective operation of short, highly efficient fused-core columns. Investigation of performance at high flow rates and elevated temperatures. Journal of Chromatography A, 1217(27), 4561-4567. https://doi.org/10.1016/j.chroma.2010.04.070

Fused core or superficially porous columns offer the advantages of higher efficiency compared with totally porous columns of the same particle size, but similar operating pressures. However, their performance may be adversely affected by extra-column... Read More about Instrumental considerations for the effective operation of short, highly efficient fused-core columns. Investigation of performance at high flow rates and elevated temperatures.

Study of the selectivity, retention mechanisms and performance of alternative silica-based stationary phases for separation of ionised solutes in hydrophilic interaction chromatography (2010)
Journal Article
McCalley, D. V. (2010). Study of the selectivity, retention mechanisms and performance of alternative silica-based stationary phases for separation of ionised solutes in hydrophilic interaction chromatography. Journal of Chromatography A, 1217(20), 3408-3417. https://doi.org/10.1016/j.chroma.2010.03.011

The separation of a mixture of neutral, strongly acidic and strongly basic compounds was studied in hydrophilic interaction chromatography using a bare silica phase, and bonded silica phases with diol, zwitterionic, amide and hydrophilic/hydrophobic... Read More about Study of the selectivity, retention mechanisms and performance of alternative silica-based stationary phases for separation of ionised solutes in hydrophilic interaction chromatography.

Further investigations of the effect of pressure on retention in ultra-high-pressure liquid chromatography (2010)
Journal Article
Fallas, M. M., Neue, U. D., Hadley, M. R., & McCalley, D. V. (2010). Further investigations of the effect of pressure on retention in ultra-high-pressure liquid chromatography. Journal of Chromatography A, 1217(3), 276-284. https://doi.org/10.1016/j.chroma.2009.11.041

In this study, we investigated further the large increases in retention with pressure that we observed previously in RP-LC especially for ionised solutes. These findings were initially confirmed on a conventional silica C18 column, which gave extreme... Read More about Further investigations of the effect of pressure on retention in ultra-high-pressure liquid chromatography.

Practical assessment of frictional heating effects and thermostat design on the performance of conventional (3 μm and 5 μm) columns in reversed-phase high-performance liquid chromatography (2009)
Journal Article
Fallas, M. M., Hadley, M. R., & McCalley, D. V. (2009). Practical assessment of frictional heating effects and thermostat design on the performance of conventional (3 μm and 5 μm) columns in reversed-phase high-performance liquid chromatography. Journal of Chromatography A, 1216(18), 3961-3969. https://doi.org/10.1016/j.chroma.2009.03.007

A practical investigation of frictional heating effects in conventional C18 columns was undertaken, to investigate whether problems found for sub-2 μm columns were also present for those of particle size 3 μm and 5 μm and different internal diameter.... Read More about Practical assessment of frictional heating effects and thermostat design on the performance of conventional (3 μm and 5 μm) columns in reversed-phase high-performance liquid chromatography.

A new approach to the determination of column overload characteristics in reversed-phase liquid chromatography (2009)
Journal Article
Dai, J., Carr, P. W., & McCalley, D. V. (2009). A new approach to the determination of column overload characteristics in reversed-phase liquid chromatography. Journal of Chromatography A, 1216(12), 2474-2482. https://doi.org/10.1016/j.chroma.2009.01.036

Column overloading is very common during the separations of basic analytes in analytical scale reversed-phase liquid chromatography (RPLC). Due to the complex interactions of ionic analytes with stationary and mobile phases, only a very small amount... Read More about A new approach to the determination of column overload characteristics in reversed-phase liquid chromatography.

Investigation of the effect of pressure on retention of small molecules using reversed-phase ultra-high-pressure liquid chromatography (2008)
Journal Article
Fallas, M. M., Neue, U. D., Hadley, M. R., & McCalley, D. V. (2008). Investigation of the effect of pressure on retention of small molecules using reversed-phase ultra-high-pressure liquid chromatography. Journal of Chromatography A, 1209(1-2), 195-205. https://doi.org/10.1016/j.chroma.2008.09.021

The effect of inlet pressure on the retention of a series of low molecular weight acids, bases and neutrals, was investigated at constant temperature in reversed-phase liquid chromatography using a commercial ultra-high-pressure system (Waters UPLC i... Read More about Investigation of the effect of pressure on retention of small molecules using reversed-phase ultra-high-pressure liquid chromatography.

Evaluation of the properties of a superficially porous silica stationary phase in hydrophilic interaction chromatography (2008)
Journal Article
McCalley, D. V. (2008). Evaluation of the properties of a superficially porous silica stationary phase in hydrophilic interaction chromatography. Journal of Chromatography A, 1193(1-2), 85-91. https://doi.org/10.1016/j.chroma.2008.04.007

The sample capacity, column efficiency (and its variation with flow) of a superficially porous unbonded silica phase (Halo) was investigated using hydrophilic interaction chromatography (HILIC), particularly for separation of basic compounds. Sample... Read More about Evaluation of the properties of a superficially porous silica stationary phase in hydrophilic interaction chromatography.

Estimation of the extent of the water-rich layer associated with the silica surface in hydrophilic interaction chromatography (2008)
Journal Article
McCalley, D. V., & Neue, U. D. (2008). Estimation of the extent of the water-rich layer associated with the silica surface in hydrophilic interaction chromatography. Journal of Chromatography A, 1192(2), 225-229. https://doi.org/10.1016/j.chroma.2008.03.049

The possible presence of a mobile phase layer rich in water on the surface of silica columns used under conditions typical in hydrophilic interaction chromatography was investigated by the injection of a small hydrophobic solute (benzene) using aceto... Read More about Estimation of the extent of the water-rich layer associated with the silica surface in hydrophilic interaction chromatography.

Analysis of basic compounds by reversed-phase high-performance liquid chromatography using hybrid inorganic/organic phases at high pH (2008)
Journal Article
Davies, N. H., Euerby, M. R., & McCalley, D. V. (2008). Analysis of basic compounds by reversed-phase high-performance liquid chromatography using hybrid inorganic/organic phases at high pH. Journal of Chromatography A, 1178(1-2), 71-78. https://doi.org/10.1016/j.chroma.2007.11.040

The retention and mass overload of five bases and a quaternary ammonium compound were studied on a bridged ethyl hybrid inorganic/organic phase (XBridge C18) over a pH range 2.7-12.0 using acetonitrile-phosphate and carbonate buffers. Some comparison... Read More about Analysis of basic compounds by reversed-phase high-performance liquid chromatography using hybrid inorganic/organic phases at high pH.