ORIGINAL PAPER Determination of selected pesticides in environmental water by employing liquid-phase microextraction and liquid chromatography–tandem mass spectrometry Tatjana Trtić-Petrović & Jelena Ðorđević & Nikolina Dujaković & Ksenija Kumrić & Tatjana Vasiljević & Mila Laušević Received: 29 January 2010 / Revised: 1 April 2010 / Accepted: 6 April 2010 / Published online: 5 May 2010 # Springer-Verlag 2010 Abstract An optimised extraction and cleanup method for the analysis of pesticide in natural water samples is presented. Sixteen pesticides of different polarity and from the different chemical classes (organophosphates, triazines, benzimidazoles, carbamates, carbamides, neonicotinoides, methylureas, phenylureas and benzohydrazides), most frequently used in Serbia, were selected for the analysis. Liquid-phase microextraction in a single hollow fibre (HF- LPME) has been applied for sample preparation. The concentrations of pesticides were determined using HPLC- MS/MS method with electrospray ionisation. The extraction behaviour and selection of the experimental conditions was predicted based on log D and pK a values of targeted pesticides, which were calculated applying the computer software ACD/Labs PhysChem Suite v12. The influence of the donor pH and concentration of pesticides, organic phase composition as well as the extraction time on the extraction efficiency was investigated. Optimum extraction conditions were evaluated with respect to the investigated parameters of the extraction. The extraction method was validated for 10 out of 16 studied pesticides. Linear range of the pesticides was 0.1–5 μg L -1 with the correlation coefficient from 0.991 to 0.9998, and the relative standard deviation for three standard measurements was between 0.2 and 11.8%. The limits of detections ranged from 0.026 to 0.237 μg L -1 and the limits of quantifications from 0.094 to 0.793 μg L -1 . The optimised two-phase HF-LPME method was successfully applied for determination of moderately polar as well low-polar pesticides in the environmental water samples. Keywords HPLC-MS/MS . Liquid-phase microextraction . Pesticides . Sample preparation Introduction The term pesticide is used broadly for chemicals, synthetic or natural, that are used for the control of insects, fungi, bacteria, weeds, nematodes, rodents and other pests [1]. Agricultural production currently, and increasingly, depends on the use of pesticides. These compounds and the products of their degradation or metabolism may spread through the environ- ment and frequently contaminate surface and ground waters, soil, agricultural products and food. Determination of pesticides in the environmental samples is of great interest because of their toxicity, carcinogenicity, or endocrine disrupting effects [2]. The analysis of pesticides poses special problems since the pesticides belong to different chemical groups, have a wide range of polarity and acidic characteristics, their concentration in environmental samples is very low and the matrix is complex. Thus, the interest in the field of pesticides analysis is focusing on improving methodologies, with regard to how rapidly, accurately, and sensitively the pesticides can be determined [3]. Sample preparation is among the most important steps in any analytical process. The macromolecules and other Presented at the 6th Instrumental Methods of Analysis Conference (IMA 2009) held in Athens, Greece from 4th–8th October 2009. T. Trtić-Petrović (*) : J. Ðorđević : K. Kumrić Vinča Institute of Nuclear Sciences, Laboratory of Physics, P.O. Box 522, 11001 Belgrade, Serbia e-mail: ttrtic@vinca.rs N. Dujaković : T. Vasiljević : M. Laušević Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia Anal Bioanal Chem (2010) 397:2233–2243 DOI 10.1007/s00216-010-3725-5