129887 20241125101134.0 doi 10.1007/s00764-023-00256-x sideral 136193 ART-2023-136193 eng Jarne, Carmen Universidad de Zaragoza (orcid)0000-0002-8701-9745 Gradient high-performance thin-layer chromatography for characterizing complex hydrocarbon-containing products 2023 Access copy available to the general public Unrestricted Classic saturates, aromatics, resins, and asphaltenes (SARA) analysis has long enabled the chromatographic separation of complex hydrocarbon-containing products into these four families. This simplification often does not provide sufficient or correct information on the relationship between the composition of the products and the process variables studied. The obtention of profiles by gradient automated multiple development (AMD) is an interesting alternative to obtain extended SARA separations with increasing level of complexity for heavy petroleum products that adequately represent the entirety of the sample. An optimized 20-step gradient based on tetrahydrofuran (THF)‒dichloromethane‒n-heptane over a total migration distance of 83 mm is proposed here to characterize all types of heavy oil products. The combination of ultraviolet (UV)–densitometry (at 201, 228, and 273 nm), fluorescence detection by intensity changes using berberine cation, together with on-plate recording of UV spectra of separated peaks and the comparison with those of standards, allow for a deep characterization of chemical families. In the apolar zone of the chromatogram saturates, naphthenes, naphteno-aromatics, alkyl-aromatics, and aromatics with different degrees of condensation are detected. The use of THF, both in the plate precleaning stage and in the first stages of the gradient, is responsible for the satisfactory resolution of the resins in the polar zone. AMD chromatographic zones can be related to peaks from hydrocarbon groups in classical SARA. The application of this gradient to different types of products allowed for the relation of the profiles of bitumen to their origin, differentiation of the resin part trapped in asphaltenes, control performance of deasphalting in hydrorefining products, and the control of the composition of base oils. info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ 1.1 2023 CHEMISTRY, ANALYTICAL 89 / 106 = 0.84 2023 Q4 T3 0.352 2023 Analytical Chemistry 2023 Q3 Clinical Biochemistry 2023 Q3 Biochemistry 2023 Q3 2.2 2023 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Cebolla, Vicente L. Membrado, Luis Escuín, José M. (orcid)0000-0002-5645-6723 Vela, Jesús Universidad de Zaragoza (orcid)0000-0002-4887-1652 2009 750 Universidad de Zaragoza Dpto. Química Analítica Área Química Analítica 36 (2023), 335–349 JPC, J. planar chromatogr. mod. TLC JPC-JOURNAL OF PLANAR CHROMATOGRAPHY-MODERN TLC 0933-4173 2638865 http://zaguan.unizar.es/record/129887/files/texto_completo.pdf Versión publicada 2506247 http://zaguan.unizar.es/record/129887/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:129887 articulos driver 2024-11-22-12:00:02 ARTICLE