Critical review of methods for the determination of purity by differential scanning calorimetry*
1976; Elsevier BV; Volume: 14; Issue: 1-2 Linguagem: Inglês
10.1016/0040-6031(76)80053-6
ISSN1872-762X
Autores Tópico(s)Crystallization and Solubility Studies
ResumoDuring the past few years several publications have appeared in the literature describing purity determinations by differential scanning calorimetry (DSC). Some controversies remain, however, such as the proper choice of limits for the slope determination in the plot of the sample temperature vs. the reciprocal of the fraction melted, and the applicable purity, range of the DSC method. Most authors have accepted a purity of 98% as the lowest workable level. This presentation will demonstrate the possible use of DSC techniques for lower purity measurements. Four systems for obtaining the impurity content were investigated, i.e., dynamic DSC with time-sharing and on-line computer data acquisition, stepwise DSC, and the two-peak method. The applicable purity ranges were found to depend on the instrumentation and data acquisition systems used.
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