ORIGINAL PAPER Determination of methylcyclopentadienyl-manganese tricarbonyl in gasoline and water via ionic-liquid headspace single drop microextraction and electrothermal atomic absorption spectrometry Mashaallah Rahmani & Massoud Kaykhaii Received: 1 April 2011 /Accepted: 20 June 2011 /Published online: 30 June 2011 # Springer-Verlag 2011 Abstract We report on a rapid and effective method for the determination of methylcyclopentadienyl-manganese tricar- bonyl (MMT) in water and gasoline samples. It is based on single drop microextraction using a 2.5 μL drop of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate. The influence of ionic liquid, volume of the micro-drop, extraction time, ionic strength and volume of sample were investigated. MMT was then quantified by electrothermal atomic absorption spectrometry. The method has a wide linear range (R 2 =0.991), a detection limit (3σ) of 10.0 ng L -1 , a standard deviation of 4.8% (for n =5), an enrichment factor of 124, and gives relative recoveries of 81.2–101.0%. It was successfully applied to the determina- tion of MMT in water and gasoline samples. Keywords Ionic Liquid (IL) . Headspace single drop microextraction (HS-SDME) . Methylcyclopentadienyl- manganese tricarbonyl (MMT) . Electrothermal atomic absorption spectrometry (ET-AAS) . Gasoline analysis Introduction Increasing attention has been given in recent years to the use of manganese additives for improving combustion processes of various fuel oils. Organometallic compounds such as methylcyclopentadienyl-manganese tricarbonyl (MMT: CH 3 C 5 -H 4 Mn(CO) 3 ), the additive AK-33X, have found application in unleaded gasoline fuels and in the formulation of heating oils as an antiknock agent and octane improver. The combustion of MMT leads to the emission of oxides of manganese to the atmosphere. Levels of 5 μg Mn L -1 have been reported to lead to chronic manganese poisoning and leading to severe injury to kidneys, liver, lungs and the central nervous system [1–3]. MMT has been found in air and roadside dirt. Its health concerns have been raised recently because the use of MMT in gasoline is expected to increase in the future [4]. On the other hand, the control of the methylcyclopentadienyl manganese tricarbonyl concentration is important in the control of the anti-knock property of gasoline. Considerable literature exists about the determination of organomanganese compound analysis in gasoline but, because of the high concentration levels of these samples, no preconcentration steps are included in the analytical procedures. Nevertheless, when the organomanga- nese compounds need to be quantified in samples expected to content low concentration levels, preconcentration steps must be included [5]. The rapid and solvent-free preconcentration technique of single-drop microextraction (SDME) is an interesting alterna- tive to classical techniques, and has been applied for the analysis of various analytes in different samples [6–9]. The inorganic applications of this technique for sample prepara- tion was appeared in 2003 [10]. SDME is a simple, inexpensive, fast, effective and virtually solvent-free sample pretreatment technique. However, because of the vaporiza- tion, the extracting droplets may be lost from the needle tip of the microsyringe during extraction, therefore it is not very robust, moreover, still there is a need for examining a range of organic solvents for finding the best acceptor phase. Ionic liquids (ILs) are solvents consisting of organic cations and various anions. Compared with conventional solvents, ILs possess many unique properties such as M. Rahmani : M. Kaykhaii (*) Department of Chemistry, Faculty of Sciences, University of Sistan and Baluchestan, Zahedan 98135–674, Iran e-mail: kaykhaii@hamoon.usb.ac.ir Microchim Acta (2011) 174:413–419 DOI 10.1007/s00604-011-0648-6