Determination of luteolin and apigenin in celery using ultrasonic-assisted extraction based on aqueous solution of ionic liquid coupled with HPLC quantification

BACKGROUND: Ionic liquids are a class of organic salts with melting points equal to or below 100 degrees C, and their use in sample preparation has shown its promise, for example, in alleviation of environmental pollution and improvement of selectivity and extraction of certain interesting compounds. RESULTS: Optimal conditions were obtained by using 1.0 mol L-1 1-butyl-3-methylimidazolium methylsulfate ([Bmim][MS]) aqueous solution at pH 1.0 as the extraction solvent. An ultrasonic power of 200 W was chosen to ensure complete dispersion of [Bmim][MS] into celery in 90 min and the solid : liquid ratio was 1 : 10. CONCLUSION: The proposed ultrasonic assistant extraction approach, based on ionic liquid aqueous solution, exhibited satisfactory results, with recovery values ranging from 72.7% to 89.5%. Under optimal conditions, compared with conventional solvent extraction amounts of luteolin and apigenin were more than doubled. (C) 2011 Society of Chemical Industry