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Professor David McCalley's Outputs (54)

Investigation of the effect of pressure on retention of small molecules using reversed-phase ultra-high-pressure liquid chromatography (2008)
Journal Article

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

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

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

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.

Is hydrophilic interaction chromatography with silica columns a viable alternative to reversed-phase liquid chromatography for the analysis of ionisable compounds? (2007)
Journal Article

The separation of acidic, neutral and particularly basic solutes was investigated using a bare silica column, mostly under hydrophilic interaction chromatography (HILIC) conditions with water concentrations >2.5% and with >70% acetonitrile (ACN). Pro... Read More about Is hydrophilic interaction chromatography with silica columns a viable alternative to reversed-phase liquid chromatography for the analysis of ionisable compounds?.

A study of retention and overloading of basic compounds with mixed-mode reversed-phase/cation-exchange columns in high performance liquid chromatography (2007)
Journal Article

The retention and overload of bases were studied on two new mixed-mode, silica based phases possessing ionic carboxylate functionalities of different acidity embedded within a hydrophobic ligand (SiELC Primesep™). At low pH, good peak shapes were obt... Read More about A study of retention and overloading of basic compounds with mixed-mode reversed-phase/cation-exchange columns in high performance liquid chromatography.

Study of overload for basic compounds in reversed-phase high performance liquid chromatography as a function of mobile phase pH (2006)
Journal Article

The retention and overloading properties for eight basic solutes and two quaternary ammonium compounds were studied over the pH range 2.7-10.0 using phosphate and carbonate buffers. At low pH, a hybrid inorganic-organic silica-ODS phase (XTerra RP-18... Read More about Study of overload for basic compounds in reversed-phase high performance liquid chromatography as a function of mobile phase pH.

Study of overloading of basic drugs and peptides in reversed-phase high-performance liquid chromatography using pH adjustment of weak acid mobile phases suitable for mass spectrometry (2005)
Journal Article

Serious losses in column efficiency for ionised basic drugs and peptides occur due to overloading of C18 phases when weak acid mobile phases of low ionic strength suitable for mass spectrometric detection are used. Measurable changes in retention tim... Read More about Study of overloading of basic drugs and peptides in reversed-phase high-performance liquid chromatography using pH adjustment of weak acid mobile phases suitable for mass spectrometry.

Rationalization of retention and overloading behavior of basic compounds in reversed-phase HPLC using low ionic strength buffers suitable for mass spectrometric detection (2003)
Journal Article

The retention and overloading behavior of some basic (and acidic) compounds has been studied on different RP-HPLC columns in buffers of varying ionic strength. Anomalous retention patterns of acids and bases were found on one phase in low-pH, volatil... Read More about Rationalization of retention and overloading behavior of basic compounds in reversed-phase HPLC using low ionic strength buffers suitable for mass spectrometric detection.

Overloading study of bases using polymeric RP-HPLC columns as an aid to rationalization of overloading on silica-ODS phases (2002)
Journal Article

The separation of ionized bases by reversed-phase liquid chromatography with alkyl silica columns often leads to severely tailed bands that are highly detrimental. Band shape and its dependence on sample mass are notably different when mobile-phase p... Read More about Overloading study of bases using polymeric RP-HPLC columns as an aid to rationalization of overloading on silica-ODS phases.