A. C. Sahayam
Bhabha Atomic Research Centre, Hyderabad
Title: Determination of cobalt compounds in functional drinks and nutritive supplements using HPLC-ICP-MS
Biography
Biography: A. C. Sahayam
Abstract
Speciation analysis of cobalt in nutritive supplements has been carried out using HPLC and ICP-MS equipped with a membrane desolvation sample introduction system as detector. In this study, cobalt containing compounds, namely Co(II), cyanocobalamin (CN-Cbl), hydroxylcobalamin (OH-Cb1), 5’-deoxyladenosylcobalamin (Ado-Cbl) and methylcobalamin (Me-Cbl), were well separated by reversed phase HPLC with a microbore C8-HPLC column as the stationary phase. Gradient elution using ammonium acetate and acetonitrile at pH 4 allowed the chromatographic separation of all species, including strongly adsorbed Ado-Cbl and Me-Cbl, in less than 14 minutes. Detection limit was in the range of 0.007-0.031 ng Co mL-1 for various Co species. We determined the concentrations of cobalt containing compounds in selected nutritive supplements and two functional drinks. Over 91% of the total cobalt species was extracted using a 0.5% v/v HNO3 solution in a microwave field at 70oC within a period of 10 min; and the spike recovery was in the range of 94-101% for various species. The HPLC-ICP-MS results showed a satisfactory agreement with the total cobalt concentrations obtained by ICP-MS analysis of functional drinks and dissolved nutritive supplements samples.