dc.creatorCARVALHO, PRN
dc.creatorCOLLINS, CH
dc.creatorRODRIGUEZAMAYA, DB
dc.date1992
dc.dateFEB
dc.date2014-12-16T11:32:50Z
dc.date2015-11-26T16:56:27Z
dc.date2014-12-16T11:32:50Z
dc.date2015-11-26T16:56:27Z
dc.date.accessioned2018-03-28T23:43:52Z
dc.date.available2018-03-28T23:43:52Z
dc.identifierChromatographia. Friedr Vieweg Sohn Verlag Gmbh, v. 33, n. 41732, n. 133, n. 137, 1992.
dc.identifier0009-5893
dc.identifierWOS:A1992HG58900006
dc.identifier10.1007/BF02275893
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/56280
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/56280
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/56280
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1277381
dc.descriptionThe provitamin A content of some food samples was determined by methods involving MgO:Hyflosupercel gravity-flow column chromatography (GFCC) and reversed phase high performance liquid chromatography (HPLC), the quantitation being done by external standardization (HPLC-ES) or internal standardization (HPLC-IS) with Sudan. The results obtained with alpha- and beta-carotene in carrots, beta-carotene and beta-cryptoxanthin in papaya and beta-carotene in tomato and kale agreed well, showing that any of the these techniques can be used, provided the analysis is done under optimum conditions. Good separation of the different provitamins using GFCC depends on the analyst's skill and visual acuity. HPLC-ES required a constant supply of provitamin standards, thus the varying purity of commercially available standards and the high instability of these compounds could pose grave problems. Due to the stability of Sudan, HPLC-IS appeared to be the method of choice although passage of the extract through a MgO: Hyflosupercel minicolumn was required prior to injection to separate chlorophylls, dihydroxy- and polyoxycarotenoids which would otherwise elute with Sudan. Nonconformity of the Sudan structure to those of the provitamins did not effect the quantitative results. The chromatographic separation, identity and quantification of the provitamins could be more easily established by using HPLC-IS, complemented with GFCC.
dc.description33
dc.description41732
dc.description133
dc.description137
dc.languageen
dc.publisherFriedr Vieweg Sohn Verlag Gmbh
dc.publisherWiesbaden 1
dc.publisherAlemanha
dc.relationChromatographia
dc.relationChromatographia
dc.rightsfechado
dc.sourceWeb of Science
dc.subjectCOLUMN LIQUID CHROMATOGRAPHY
dc.subjectGRAVITY-FLOW COLUMN CHROMATOGRAPHY
dc.subjectPROVITAMIN-A DETERMINATION
dc.subjectCarotenoids
dc.subjectFoods
dc.titleCOMPARISON OF PROVITAMIN-A DETERMINATION BY NORMAL-PHASE GRAVITY-FLOW COLUMN CHROMATOGRAPHY AND REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY
dc.typeArtículos de revistas


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