Determination of Iodide in Beer using Monolithic Silica Disk Packed Spin Column and Reversed-phase Liquid Chromatography/Electrochemical Detection

A method for determining the concentration of iodide in beer using high-performance liquid chromatography/electrochemical detection was developed. Simple sample pretreatment of beer was performed using a monolithic silica disk-packed spin column, with a recovery rate of 84.9%. Separation of iodide ions from other endogenous compounds was carried out using a mobile phase of 10 mM sodium phosphate buffer containing 8 mM hexadecyltrimethylammonium chloride on an ODS column, followed by electrochemical detection with a diamond electrode. The detection limit for iodide ion was 0.02 nM, and the calibration curve was linear in the range of 0.05–10 μM (R2 = 0.9991). I applied this method to the determination of iodide in beer. The iodide concentrations in beer were 68±10.2 nM (mean±S.D., n=4).