SHORT COMMUNICATION Microextraction of Rosmarinic Acid Using CMK-3 Nanoporous Carbon in a Packed Syringe Akram Rahimi • Payman Hashemi • Alireza Badiei • Mehdi Safdarian • Marzieh Rashidipour Received: 11 October 2012 / Revised: 13 April 2013 / Accepted: 17 April 2013 / Published online: 26 April 2013 Ó Springer-Verlag Berlin Heidelberg 2013 Abstract CMK-3 nanoporous carbon was prepared and used as an efficient sorbent for microextraction in packed syringe of rosmarinic acid in Rosmarinus officinalis L. (rosemary). In the proposed method, only 2 mg of the nanoporous material, inserted between a syringe’s barrel and needle, was sufficient for the extraction with minimum consumption of organic solvents. Sample preparation was performed on the packed bed using a laboratory-made pro- grammable apparatus. The apparatus was designed and used for automation of the conditioning, sampling, washing and elution steps of the method, and increasing the reproduc- ibility of the experiments. For optimization of the experi- mental parameters, a central composite design method was used. Under the optimized conditions (i.e., number of adsorption cycles 14 times, number of elution cycles ten times and volume of elution 100 lL), an extraction recovery of 90 (±4.5) % was obtained for rosmarinic acid. The same packing bed could be used for at least 80 extractions without significant changes in its properties. The efficiency of the nanoporous sorbent was found to be superior to that of activated carbon, by a factor of about 17. The proposed method was successfully applied to the extraction of three rosemary samples before analysis by HPLC. Keywords High performance liquid chromatography Á Microextraction in packed syringe Á CMK-3 nanoporous carbon Á Rosmarinic acid Introduction Sample preparation is of critical importance for the anal- ysis, especially for samples with a complex matrix. The purpose of this step is to remove interfering materials and enrichment of the analytes. Among commonly used sample preparation methods, liquid–liquid extraction is time-con- suming and require the use of organic solvents, which are dangerous for health and the environment. Solid phase extraction (SPE) also requires relatively large quantities of sample and solvents or solvent mixtures [1–4]. Solid phase microextraction (SPME), due to its simple, solventless and flexible properties, has gained a widespread acceptance in many areas as an alternative to the conventional sampling techniques [5–7]. The major disadvantages of SPME in quantitative analysis are low recovery and high sensitivity to the nature of sample matrix. Microextraction in packed syringe (MEPS) was first described by Abdel-Rehim [8], as a new development in the field of sample preparation. MEPS is in fact a miniaturization of the conventional SPE that may be directly coupled to GC or LC [9–11]. In the MEPS technique, the packing is inserted directly into the barrel of a syringe or between the syringe barrel and the injection needle, not into a separate column [12]. Many sorbent materials, such as silica-based, strong cation exchangers, restricted access materials, carbon, polysty- rene–divinyl benzene copolymer, and molecular imprinted polymers can be used in this method [13]. MEPS will reduce sample preparation time and organic solvent con- sumption. MEPS is fast and may be easily automated, thus, A. Rahimi Á P. Hashemi (&) Á M. Safdarian Department of Chemistry, Faculty of Science, Lorestan University, Khoramabad, Iran e-mail: payman_hashemi@yahoo.com A. Badiei School of Chemistry, College of Science, University of Tehran, Tehran, Iran M. Rashidipour Razi Herbal Medicines Research Center, Lorestan University (Medical Sciences), Khoramabad, Iran 123 Chromatographia (2013) 76:857–860 DOI 10.1007/s10337-013-2471-1