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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., Buckenmaier, S. 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
McCalley, D. V., 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.

Performance of silica monoliths for basic compounds. Silanol activity (2011)
Book Chapter
McCalley, D. V. (2011). Performance of silica monoliths for basic compounds. Silanol activity. In K. K. Unger, N. Tanaka, & E. Mactejevas (Eds.), Monolithic silicas in separation science, 173-188. Wiley VCH

The large majority of pharmaceuticals, and in addition many compounds of biomedical significance, contain ionisable basic groups. This chapter considers the analysis of these important compounds on silica monolith columns.

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.

The challenges of the analysis of basic compounds by high performance liquid chromatography: Some possible approaches for improved separations (2010)
Journal Article
McCalley, D. V. (2010). The challenges of the analysis of basic compounds by high performance liquid chromatography: Some possible approaches for improved separations. Journal of Chromatography A, 1217(6), 858-880. https://doi.org/10.1016/j.chroma.2009.11.068

This review considers some of the difficulties encountered with the analysis of ionised bases using reversed-phase chromatography, such as detrimental interaction with column silanol groups, and overloading which both lead to poor peak shapes. Method... Read More about The challenges of the analysis of basic compounds by high performance liquid chromatography: Some possible approaches for improved separations.

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.