Determinação de carotenoides provitamina a por cromatografia em coluna aberta e cromatografia liquida de alta eficiencia

AUTOR(ES)
DATA DE PUBLICAÇÃO

1990

RESUMO

The provitamin content of some food samples was determined by methods involving chromatography on a MgO: Hyflosupercel open colunm (OCC) and reversed phase high performance liquid chromatography, the quantitation being done by external standardization (HPLC-ES) or internal standardization (HPLC-IS) with Sudan. The results obtained with a- and b-carotene in carrots and Dende oil, b-carotene and b-criptoxanthin in papaya and b-carotene in tomato and kale agreed well, showing that anyone of the three techniques can be used, provided the analysis is done under optimum conditions, Good separation of the different provitamins in OCC depended on the analyst´s skill and visual acuit. HPLC-ES required a constant supply of provitamin standards i; thus the varying purity of commercially available standards and the high instability of these compounds posed grave problems. Due the stability of Sudan, HPLC-IS appeared to be the method of choice although passage of the extract through a MgO: Hyflosupercel minicolunm was needed prior to injection to separate chrorophylls and dihydroxy and trihydroxycarotenoids which would otherwise elute with Sudan. Nonconformity of the Sudan structure to those of the provitamins did not affect the quantitative results. The chromatographic separation and identity of lhe provitamins could be more easily established by using HPLC-IS, complemented with OCC.

ASSUNTO(S)

cromatografia liquida analise cromatografica

ACESSO AO ARTIGO

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