Melting temperature and heat of fusion of cytosine revealed from fast scanning calorimetry

Melting properties of peptides and their solubility in water. Part 1: dipeptides based on glycine or alanine

“…FSC has been successfully applied to accurate study of meting of amino acids glycine and L-alanine, 24 bio-polymers, [26][27][28] low molecular mass compounds 29 and nucleobases. 30,31 Further, for glycine and Lalanine we have shown that it is possible to predict the temperature-dependent solubility in water on the basis of the FSC-determined melting properties. 24 Within this work the temperature-dependent aqueous solubilities of glycyl-glycine (Gly-Gly), glycyl-L-alanine (Gly-Ala), Lalanyl-glycine (Ala-Gly), L-alanyl-L-alanine (Ala-Ala) and cyclo(Lalanyl-glycine) (cyclo(Ala-Gly)) were measured gravimetrically and photometrically.…”

“…The detailed description of the experimental method has been given previously. 24,27,28,30 The measurement procedure is divided into three measurement stages, as shown in the temperature-time prole in Fig. 1.…”

New experimental melting properties as access for predicting amino-acid solubility

“…The experimental data for L-alanine and glycine were measured using fast scanning calorimetry (FSC) which avoids thermal decomposition before and during melting, as has been successfully employed for melting of bio-polymers, 11,12 for low molecular mass compounds 13 and for the nucleobase cytosine. 14 In the present paper, the melting parameters of pure amino acids have been successfully measured. The melting temperatures for L-alanine and glycine are (608 AE 9) K and (569 AE 7) K respectively, while the enthalpies of fusion are (22 AE 5) kJ mol À1 and (21 AE 4) kJ mol À1 , respectively.…”

“…However, the surface-to-volume ratio increases for such small sample, and this would create signicant mass loss due to evaporation or sublimation at elevated temperatures. 14,17 This mass loss was partially suppressed by coating the sample with silicon oil. Fig.…”

Challenge and Solution of Characterizing Glass Transition Temperature for Conjugated Polymers by Differential Scanning Calorimetry

“…In addition, since P3(2EB)T is able to be quenched into fully amorphous state with Flash DSC, the effects of chain rigidity and crystallization can be deconvoluted. Based on the symmetric line analysis method, we estimated the sample mass of P3(2EB)T in Flash DSC measurement to be approximately 67 ng. Hence, the Δ c p ,am at T g for the fully amorphous P3(2EB)T is calculated to be approximately 0.14 J g −1 K −1 , two times smaller than PS and r‐ran P3HT (0.28–0.3 J g −1 K −1 ).…”