Liquid chromatographic determination of Vitamin D3 in infant formulas and fortified milk Original Research Article

An isocratic reverse-phase liquid chromatographic (LC) method with electrochemical (EC) detection has been developed and validated for determining Vitamin D3 in fortified milk and infant formulas. LC–EC determination provides linear responses in the range from 0.03 to 0.7 μg Vitamin D3/ml, with inter- and intra-day variations (R.S.D.%) of 4.1 and 4.4, respectively, and detection and quantification limits of 0.012 ng in assay (48 ng/100 g of sample) and 0.039 ng in assay (156 ng/100 g of sample), respectively. Application of the method to a set of infant formulas and fortified milk confirmed its usefulness.