Eryngium planum, is distributed worldwide in temperate climates and widely found in Iran [1]. There are many flavonoids present in Eryngium planum in low concentrations, which remain unidentified [2]. Therefore, an efficient, simple and inexpensive sample preparation technique with high preconcentration factor is necessary in flavonoid analysis. Several analytical techniques have been used for determining the amount of flavonoids in different matrices such as GC-MS, HPLC, EC and Voltametery [3]. Nevertheless, due to the complexity of sample matrices, the preconcentration steps are necessary. Along all of the extraction methods, solid phase microextraction is a high-performance, powerful, rapid and inexpensive microextraction used for analytes extraction and preconcentration from aqueous samples. Flavonoids were extracted in a two-step procedure. First, 0.10g of dried and powdered Eryngium planum was extracted with 10 mL of hydroalcholic solvent in an ultrasonic bath for 20 min. Under the optimum conditions, the values of intra and inter day RSD were in the range of 3.48–5.63% and 6.55–09.07%, respectively. The limits of detection (LODs) ranged between 0.5 and 7.0 ngmL-1. Extraction recoveries and enrichment factors were in the range of 96– 98℅ and 179–324, respectively. The method was successfully applied for the preconcentration and determination of seven flavonoids in leaves of Eryngium planum. samples. The main advantages of this method are its simplicity of operation, low cost, high recovery and high enrichment factor due to the use of non-toxic surfactant solution instead of the toxic organic extraction solvents.
