Rapid and Direct Microextraction of Pesticide Residues from Rice and Vegetable Samples by Supramolecular Solvent in Combination with Chemometrical Data Processing Setare Gorji 1 & Pourya Biparva 2 & Morteza Bahram 1 & Ghorbanali Nematzadeh 3 Received: 13 July 2018 /Accepted: 21 September 2018 # Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract In this work, a rapid, simple, and environmentally friendly method has been proposed for direct supramolecular microextraction of four organophosphate insecticides (ethion, phosalone, diazinon, chlorpyrifos) and an isothiazolidine acaricide (hexythiazox) in agricultural product samples prior to their determination by high-performance liquid chromatography-ultraviolet spectroscopy. These five target pesticides have been selected as models in combination with chemometrical optimization processing due to their high consumption in rice, cucumber, and tomato samples for pest control. Method is based on the extraction of pesticide residues from homogenized food sample in an aqueous media containing some tetrahydrofuran (THF) and decanoic acid (DeA). Effects of the experimental parameters, including THF volume, DeA content, salt concentration (as a measure of salting-out effect), and pH on extraction recoveries (ERs) and enrichment factors (EFs) were investigated and, then, the significant variables were optimized using central composite design (CCD) as chemometrical processing. At optimum conditions, this method has a linear response over the ranges of 0.10 to 1500 μg kg −1 for target analytes. Limits of detection (LOD) of this method were found to be in the range of 0.05 to 0.20 μg kg −1 . Also, relative standard deviation (RSD) of the method was in the range of 3.45 to 12.27% and the enrichment factors ranged from 102- to 178-fold. The method was applied successfully for analysis of the pesticides in agricul- tural product samples. Keywords Central composite design . Direct supramolecular microextraction . High-performance liquid chromatography-ultraviolet spectroscopy . Pesticide residue . Rice and vegetable samples Introduction Pesticides are used on a large scale for agricultural purposes (Dorr et al. 2007; Ritter et al. 2006) because of their powerful bioactivity (Al-Degs et al. 2009) and their susceptibility to insect and disease attacks (Ridgway et al. 2007). Application of pesticides in agriculture helps to obtain higher quality veg- etables and fruits by spending a lower cost. However, use of pesticides leaves some residues in food, which threaten over- all population health and the remained residual pesticides are of noticeable importance in food quality evaluation (Goto et al. 2003). Most pesticide residues occur in food as a result of the direct application of a pesticide to a crop or farm animal or the post-harvest treatments of food commodities, such as grains to prevent pest attack (Denis and Stephen 2004). In the world, alarming levels of pesticides have been reported in air, water, soil, as well as in foods and biological materials (Lambropoulou and Albanis 2007). Hence, there is an increas- ing demand for developing rapid, reliable, and inexpensive Highlights • A rapid, simple and environmental friendly method for preconcentration and separation of trace pesticide residues has been proposed. • Method is based on the extraction of pesticide residues from homogenized food samples by direct supramolecular solvent. • Several effective parameters on extraction of pesticides were studied and optimized using a chemometrical optimization processing. • RMSSs-HPLC/UV method is applied successfully to simultaneous extraction of five pesticides in tomato, rice, and cucumber samples. * Pourya Biparva p.biparva@sanru.ac.ir 1 Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran 2 Departement of Basic Sciences, Sari Agricultural Sciences and Natural Resources University, P.O. Box 578, Sari, Iran 3 Genetic and Agricultural Biotechnology Institute of Tabarestan, Sari University of Agricultural Sciences and Natural Resources, P.O. Box 578, Sari, Iran Food Analytical Methods https://doi.org/10.1007/s12161-018-1371-2