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Analytical Estimation of Water Contents, Specific Heat Capacity and Thermal Profiles Associated with Enzymatic Model Compound β-Cyclodextrin


Affiliations
1 School of Chemical Sciences, North Maharashtra University, Jalgaon 425 001, India
2 Department of Chemistry, Shivaji University, Kolhapur 416 004, India
 

Studies of water contents of solid β-cyclodextrin (β-CD) in crystallized and vacuum dried conditions are reported. Water contents were estimated using Karl–Fischer (KF) titration and thermo-gravimetric analysis (TGA) techniques. It was found that the water contents for crystallized and vacuum-dried samples were 6.93 and 0.86 moles of water per β-CD molecule respectively. TGA studies gave values of 6.83 and 0.52 moles of water per β-CD molecule respectively. The results agree with those reported from X-ray diffraction studies. Also, the molecular weight of the vacuum dried sample was determined using vapour pressure osmometry, which agrees well with the actual molecular weight of β-CD. The thermal profiles of α-cyclodextrin (α-CD) and β-CD are presented. The differential scanning calorimetry data was used to calculate specific heat at constant pressure (Cp) at different temperatures (338.15–468.15 K). These results are compared with similar data for α-CD and discussed in terms of motional contribution to Cp values and related conformational effects.

Keywords

Cyclodextrins, Differential Scanning Calorimetry, Specific Heat Capacity, Thermo-Gravimetric Analysis.
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  • Analytical Estimation of Water Contents, Specific Heat Capacity and Thermal Profiles Associated with Enzymatic Model Compound β-Cyclodextrin

Abstract Views: 388  |  PDF Views: 113

Authors

Gaurav R. Gupta
School of Chemical Sciences, North Maharashtra University, Jalgaon 425 001, India
Pankaj D. Patil
School of Chemical Sciences, North Maharashtra University, Jalgaon 425 001, India
Vasim R. Shaikh
School of Chemical Sciences, North Maharashtra University, Jalgaon 425 001, India
Rahul R. Kolhapurkar
Department of Chemistry, Shivaji University, Kolhapur 416 004, India
Dilip H. Dagade
Department of Chemistry, Shivaji University, Kolhapur 416 004, India
Kesharsingh J. Patil
School of Chemical Sciences, North Maharashtra University, Jalgaon 425 001, India

Abstract


Studies of water contents of solid β-cyclodextrin (β-CD) in crystallized and vacuum dried conditions are reported. Water contents were estimated using Karl–Fischer (KF) titration and thermo-gravimetric analysis (TGA) techniques. It was found that the water contents for crystallized and vacuum-dried samples were 6.93 and 0.86 moles of water per β-CD molecule respectively. TGA studies gave values of 6.83 and 0.52 moles of water per β-CD molecule respectively. The results agree with those reported from X-ray diffraction studies. Also, the molecular weight of the vacuum dried sample was determined using vapour pressure osmometry, which agrees well with the actual molecular weight of β-CD. The thermal profiles of α-cyclodextrin (α-CD) and β-CD are presented. The differential scanning calorimetry data was used to calculate specific heat at constant pressure (Cp) at different temperatures (338.15–468.15 K). These results are compared with similar data for α-CD and discussed in terms of motional contribution to Cp values and related conformational effects.

Keywords


Cyclodextrins, Differential Scanning Calorimetry, Specific Heat Capacity, Thermo-Gravimetric Analysis.

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DOI: https://doi.org/10.18520/cs%2Fv114%2Fi12%2F2525-2529