Liquid chromatographic determination of geometrical retinol isomers and carotene in enteral feeding formulas.
J Chromatogr A
; 1021(1-2): 125-32, 2003 Dec 22.
Article
em En
| MEDLINE
| ID: mdl-14735981
The objective of the present study was to evaluate a practical method for separation and determination of geometrical retinol isomers and carotene in enteral feeding formulas and to analyze 17 samples of commercial formulas. By using a normal-phase HPLC column and a mobile phase consisting of 1-octanol in n-hexane, seven isomers of retinol were separated and identified from the standard solution after photolysis. For evaluation of Vitamin A activity in these formulas, simultaneous determination of total carotene was performed. The data about linearity, recovery, accuracy and precision showed the reliability of analytical procedures. In the unsaponifiable portion of samples of commercial formulas, six retinol isomers were identified: (E)-retinol; (Z)-13; (Z)-9; (Z,Z)-9,13; (Z,Z)-11,13 and (Z)-7-retinol. (Z)-13/(E)-retinol ratios ranged between 3 and 37%. The range of total Z/(E)-retinol isomers fell between 5 and 42%. Despite the high concentration of Z-isomers observed in various commercial enteral feeding formulas, none of the samples presented Vitamin A activity below 90% of that specified on the label.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Vitamina A
/
Carotenoides
/
Cromatografia Líquida de Alta Pressão
/
Nutrição Enteral
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Idioma:
En
Revista:
J Chromatogr A
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Holanda