The simultaneous determination of vitamins A, E and β-carotene in bovine milk by high performance liquid chromatography-ion trap mass spectrometry (HPLC-MS~n)

摘要

Bovine milk is considered to be a good dietary source of vitamins A, E and p-carotene. This paper describes a robust method for the simultaneous determination of these compounds using high perfor-mance liquid chromatography-ion trap mass spectrometry (HPLC-MS~n) as the determinative step. The compounds were separated with a 5 u.m Polaris 2.1 × 150 mm C18-A column and an aqueous-methanol mobile phase and the levels determined using the MS~2 fragments (vitamin A, m/z 213 and m/z 199, vita-min E m/z 165 and p-carotene m/z 413). The HPLC-MS~n was operated in the positive ion APC1 mode. The method was validated using repeatability studies, duplicate analyses, recovery experiments, proficiency study data and comparison with previously validated high performance liquid chromatographic ultravi-olet/visible (HPLC-UV/Vis) and fluorescence (HPLC-Fl) procedures used in our laboratory. Expanded measurement uncertainties were similar for HPLC-MS~n, HPLC-UV/Vis and HPLC-F1, e.g. vitamin A 45 ug/100 ml, HPLC-MS~n ±8%, HPLC-UV ±9%; vitamin E 150 μg/100 ml, HPLC-MS~n ±11%, HPLC-F1 ±9%; p-carotene 12 μg/100 ml, HPLC-MS~n ±18%, HPLC-Vis ±21%.