A Simple Determination of Thiamine in Rice (Oryza Sativa L) by High-Performance Liquid Chromatography with Post-Column Derivatization

Abstract We report a rapid high-performance liquid chromatographic method for the determination of thiamine in rice with fluorimetric post-column derivatization. The analysis system consisted of a combination of both thiamine extraction with a mixture of 0.1 M hydrochloric acid-40% methanol (0.1 M HCI-40% MeOH) solution from rice flour, and chromatographic separation and determination. To extract thiamine, the rice flour was refluxed for 30 min at 60 °C with 0.1 M HCl-40% HCI. The separation systems constituted of a Sorbax TMS column, column oven (55°C), elution system containing a mixture of 0.01 M sodium dihydrogen phosphate and 0.5 M sodium perchlorate solution, a mixing coil for chemical reaction and a spectrofluorimetric detector. The thiamine derivative compound was detected at 375 nm for excitation and 435 nm for emission. The recovery of thiamine was 94 -101%. The contents of thiamine in rice of six cultivars produced in Japan were determined by the above-mentioned HPLC method and AOAC method. The...