Differential scanning calorimetry method for purity determination: A case study on polycyclic aromatic hydrocarbons and chloramphenicol

• Published in: Thermochimica acta 2011-09, Vol.524 (1), p.1-6
• Main Authors: Kestens, V., Zeleny, R., Auclair, G., Held, A., Roebben, G., Linsinger, T.P.J.
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Arrays; benzo(a)pyrene; Biological and medical sciences; case studies; Certified reference material; Chemical and thermal methods; Chemistry; Chloramphenicol; Chromatographic methods and physical methods associated with chromatography; Chromatography; Differential scanning calorimetry; Diodes; Exact sciences and technology; gas chromatography; Homogeneity; Liquid chromatography; mass spectrometry; Mathematical analysis; Medical sciences; nuclear magnetic resonance spectroscopy; Pharmacology. Drug treatments; Polycyclic aromatic hydrocarbons; Purity
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/j.tca.2011.06.002

► Purity assessment of polycyclic aromatic hydrocarbons and chloramphenicol by DSC. ► DSC results compared with traditional purity methods. ► Different methods give different results, multiple method approach recommended. ► DSC sensitive to impurities that have similar structures as main component. In this study the validity and suitability of differential scanning calorimetry (DSC) to determine the purity of selected polycyclic aromatic hydrocarbons and chloramphenicol has been investigated. The study materials were two candidate certified reference materials (CRMs), 6-methylchrysene and benzo[ a]pyrene, and two different batches of commercially available highly pure chloramphenicol. The DSC results were compared with those obtained by other methods, namely gas and liquid chromatography with mass spectrometric detection, liquid chromatography with diode array detection, and quantitative nuclear magnetic resonance. The purity results obtained by these different analytical methods confirm the well-known challenges of comparing results of different method-defined measurands. In comparison with other methods, DSC has a much narrower working range. This limits the applicability of DSC as purity determination method, for instance during the assignment of the purity value of a CRM. Nevertheless, this study showed that DSC can be a powerful technique to detect impurities that are structurally very similar to the main purity component. From this point of view, and because of its good repeatability, DSC can be considered as a valuable technique to investigate the homogeneity and stability of candidate purity CRMs.