A comparison of the performance of calorimeters

O'Neill, M; Gaisford, Simon; Beezer, Anthony E.; Skaria, Cyrus V.; Sears, Patrick

doi:10.1007/s10973-005-7488-8

Cited by 15 publications

(2 citation statements)

References 14 publications

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“…In the following study, our goal was to determine if intrinsic differences such as cell geometry, cell volume, and stirring mode between two calorimeters (TAM III and VP‐ITC) have an impact on experimental results. Insights into the comparison of various commercially available calorimeters and the involved statistical treatment are given in the previous study . For comparison, TAM III data for the measurements at 308 K is taken from .…”

Section: Resultsmentioning

confidence: 99%

Hydrophobic interaction chromatography of proteins: Studies of unfolding upon adsorption by isothermal titration calorimetry

Rodler

Beyer

Ueberbacher

et al. 2018

J of Separation Science

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Heat of adsorption is an excellent measure for adsorption strength and, therefore, very useful to study the influence of salt and temperature in hydrophobic interaction chromatography. The adsorption of bovine serum albumin and β‐lactoglobulin to Toyopearl Butyl‐650 M was studied with isothermal titration calorimetry to follow the unfolding of proteins on hydrophobic surfaces. Isothermal titration calorimetry is established as an experimental method to track conformational changes of proteins on stationary phases. Experiments were carried out at two different salt concentrations and five different temperatures. Protein unfolding, as indicated by large changes of molar enthalpy of adsorption Δh ads, was observed to be dependent on temperature and salt concentration. Δh ads were significantly higher for bovine serum albumin and ranged from 578 (288 K) to 811 (308 K) kJ/mol for 1.2 mol/kg ammonium sulfate. Δh ads for β‐lactoglobulin ranged from 129 kJ/mol (288 K) to 186 kJ/mol (308 K). For both proteins, Δh ads increased with increasing temperature. The influence of salt concentration on Δh ads was also more pronounced for bovine serum albumin than for β‐lactoglobulin. The comparison of retention analysis evaluated by the van't Hoff algorithm shows that beyond adsorption other processes occur simultaneously. Further interpretation such as unfolding upon adsorption needs other in situ techniques.

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Section: Resultsmentioning

confidence: 99%

Hydrophobic interaction chromatography of proteins: Studies of unfolding upon adsorption by isothermal titration calorimetry

Rodler

Beyer

Ueberbacher

et al. 2018

J of Separation Science

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“…The colorimetric molybdate method is inappropriate for the mixing process of potassium silicate solution with silica sol under stirring. However, isothermal heat conduction microcalorimetry is a powerful tool to investigate complex systems; [7][8][9] this technique exhibits numerous applications, [10][11][12][13][14] but has not yet been used in silica polymerization reactions. In this paper, according to the equation, A＋B→C, using accessible data of power (Φ) and heat output (q), the change in enthalpy during the chemical reaction of the silica sol (A) and potassium silicate (B) was first calculated.…”

Section: Introductionmentioning

confidence: 99%

Combination of Silica Sol and Potassium Silicate via Isothermal Heat Conduction Microcalorimetry

et al. 2011

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Isothermal heat conduction microcalorimetry was utilized as a novel characterization method to investigate the polymerization processes of silica with both thermodynamic and kinetic parameters when the combination of silica sol and potassium silicate was stirred at temperatures of 25.0, 35.0, and 45.0 ℃. The silica polymerization was characterized by the greater enthalpy change at each higher temperature and by the reaction orders of the silica sol and potassium silicate, which varied rapidly, instantaneously, and constantly from low to high all the time, up and down in an alternate manner. When the reaction order of the silica sol and potassium silicate was 3.0, the maximum rate constant occurred at 25.0 ℃ (k＝1.22×10-4 mol -2 •dm 6 •s -1 ). The two temperature regions (25.0-35.0 ℃ region with a faster rate and 35.0-45.0 ℃ region with a lower rate) reflected a two-stage oligomerization of silica monomers with different oligomers formed in a two-step anionic mechanism. The measurements of particle size and pH value showed that the colloidal particles in the mixed silica sol and potassium silicate first dissolved, then "active" silica in the potassium silicate redeposited to make a distinct particle size distribution (Z-average size, 33.0-14.9 nm at 25.0 ℃) influenced both by pH value (9.82-11.97 at 25.0 ℃) and the mass fraction (53, 65, 75, and 85 mass/%) of the silica sol in the mixture. The processes of combination of the silica sol and potassium silicate did not result from acid-base neutralization reactions but from a complex polymerization of the "active" silica components which relate to silica monomers oligomerization with heat evolved (the total enthalpy changes, 1.6234-3.3882 J).

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Thermodynamics of Water Interaction with Human Stratum Corneum I: Measurement by Isothermal Calorimetry

Yadav

Pinto

Kasting

2007

Journal of Pharmaceutical Sciences

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A comparison of the performance of calorimeters

Cited by 15 publications

References 14 publications

Hydrophobic interaction chromatography of proteins: Studies of unfolding upon adsorption by isothermal titration calorimetry

Hydrophobic interaction chromatography of proteins: Studies of unfolding upon adsorption by isothermal titration calorimetry

Combination of Silica Sol and Potassium Silicate via Isothermal Heat Conduction Microcalorimetry

Thermodynamics of Water Interaction with Human Stratum Corneum I: Measurement by Isothermal Calorimetry

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