Determination of Cobalamin in Chlorella Food by Cation Exchange Column and Graphite Furnace Atomic Absorption Spectrometry
Shiau-dune Yang, Yu-ju Feng and Weiguang Fu*
Analysis Research and Service Center, Food Industry Research and Development Institute, 331 Shi-Pin Rd., Hsinchu City 300, Taiwan, R.O.C.
(Received: June 28, 2005; Accepted: September 14, 2005)
ABSTRACT
A method for the rapid determination of cobalamin (Vitamin B12) in chlorella food was proposed. This method utilized a strong cation exchange column to remove free cobalt (II), and the cobalamins were quantitatively determined by measuring total cobalt in the column effluent with graphite furnace atomic absorption spectrometry (GFAAS). Under optimized conditions, the method detection limit was 24 μg /100 g. The method was validated by spiking cobalamin standards in different chlorella food, recoveries from spike preparations ranged from 98.3 to 99.5%, with coefficients of variation of 1.2~4.9%. The results show the suitability of the proposed method for determining vitamin B12 in chlorella food.
Key words: cobalamin, vitamin B12, chlorella food, graphite furnace atomic absorption spectrometry (GFAAS), method detection limit