Use of packed-fiber solid-phase extraction for sample clean-up and preconcentration of vitamin B_(12) before determination

A rapid and simple preconcentration step applying packed-fiber solid-phase extraction columns has been investigated to vitamin B₁₂. The extraction performance of the new method was investigated preliminarily on vitamin functional drink. The analysis used a reversed-phase C₁₈ column, with a photo-diode array detector at 220 nm. The samples were preconcentrated with packed-fiber solid-phase extraction columns. Good linearity was observed in vitamin functional drink. The repeatability of extraction performance, expressed as relative standard deviations, was from 3.5% to 4.3%. The limit of detection (LOD) is 5 ng mL⁻¹ (S/N = 3). Finally, the method had been applied for the determination of vitamin B₁₂ in vitamin functional drink.