The effects of experimental parameters and calibration on MTDSC data

Characterization of the thermal properties of microcrystalline cellulose by modulated temperature differential scanning calorimetry

“…Therefore, nonhermatically sealed pans with a pinhole in the lid were used; for the non-anhydrous samples, these pans showed a continuous loss of water. This experimental protocol is in agreement with studies done by McPhillips et al 16,17 The sample size used was between 0.015 and 0.020 g; in this range, no in¯uence of sample size was observed.…”

The Role of Configurational Entropy in Amorphous Systems

“…The instrument was calibrated in the modulated mode for heat capacity using sapphire. A modified procedure of calibration was used according to Hill et al [40]. The suitability of the calibration and the experimental conditions were checked by comparison to the literature values of dry crystalline sucrose [41].…”

Physical Stability of Amorphous Pharmaceuticals: Importance of Configurational Thermodynamic Quantities and Molecular Mobility

“…Modulated temperature DSC is an excellent technique for rapidly measuring heat capacities of small samples. However, several experimental conditions including modulation parameters, pan‐type, purge gas, and calibration procedure must be considered to avoid erroneous results 21. Helium is usually preferred, because of its greater thermal conductivity and consequently its ability to permit aggressive temperature modulation;21–23 however, the high thermal conductivity of helium causes the cell constant to be very sensitive to changes in gas flow rate.…”

“…However, several experimental conditions including modulation parameters, pan‐type, purge gas, and calibration procedure must be considered to avoid erroneous results 21. Helium is usually preferred, because of its greater thermal conductivity and consequently its ability to permit aggressive temperature modulation;21–23 however, the high thermal conductivity of helium causes the cell constant to be very sensitive to changes in gas flow rate. Because the flow rate cannot be controlled adequately with standard flow meters, and because aggressive modulation was not required for the heat capacity measurements, nitrogen (50 mL/min) was found to be superior to helium as a purge gas.…”