Abstract: A method based on high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was developed for determination of VB12 in formula foods. The sample pretreatment was performed followed by purification using an HLB solid phase extraction column, and then the analyte was separated on a C18 reversed phase column by isocratic elution using a mobile phase consisting of methanol and 8 mmol/L ammonium acetate aqueous solution (19:81, V/V). VB12 was determined indirectly by measuring cobalt ions in samples by ICP-MS. The results showed that the analysis could be completed within 7 min, and the target compound exhibited a good peak shape. A good linearity was obtained in the range of 0.1–500 μg/L for VB12 with a correlation coefficient of 0.999. The limit of detection (LOD) was 0.02 μg/kg. The average recoveries of the method ranged from 81.3% to 103.6% with relative standard deviations of 0.4% to 4.6% for different food matrixes at three spiked levels (n = 6). The method is simple, fast and sensitive with strong resistance to matrix interference and wide dynamic range. It is applicable to various formula foods.

Key words: high performance liquid chromatography-inductively coupled plasma-mass spectrometry, formula food, VB12