Chiang Mai Journal of Science

In this work, a method of gas chromatography-mass spectrometry (GC-MS) has been developed for quantitation and identification of iodine (fortified as iodide) content in seasoning powder of instant noodle. Iodide was oxidized to iodine by 2-iodosobenzoate. The generated iodine then derivatized with N,N-dimethylaniline in a phosphate buffer, following by extraction the derivative, 4-iodo- N,N-dimethylaniline, with hexane for further separation and detection by GC-MS. Under the optimal condition, a satisfied validation of data was achieved for linearity, accuracy and precision. A calibration curve (10 – 250 mg I L^-1) was obtained from a plot between the area ratio of the derivative to the internal standard, diphenylamine, and the iodide concentration. The coefficient of determination was 0.999. The limit of detection was found to be 3 mg I L^-1. The recoveries were obtained in the range of 97% to 101%. This method can be effectively applied to determine fortified iodide in the various flavors of seasoning powder of instant noodle.