Determination of rutin and quercetin in processed foods by fast semi-micro high performance liquid chromatography

A simple and widely applicable method for the simultaneous determination of rutin and quercetin in processed foods by fast semi-micro high performance liquid chromatography was developed. The sample was refluxed with methanol on a hot water bath at 90°C and cleaned up by use of a Sep-pak C18 cartridge. The extract was chromatographed on a semi-micro column (2.1mm i. d×80mm) packed with Capcell Pak C18-SG120 (particle size 3μm) with a mobile phase of methanol-water-0.5M oxalic acid (13:36:1). Detection was achieved with a UV monitor set at 350nm. The separation was attained in 18min without gradient elution. The recoveries from buckwheat flour, soba-boro (confectionery), chocolate, soft drinks, and ham fortified with the standard mixture at levels of 2.0 to 100μg/g were 83.9-99.4% (C. V. 0.8-7.3%) for rutin and 84.7-93.8% (C. V. 1.5-5.8%) for quercetin. The detection limit was 0.05μg/g for each compound.