Abstract
A simple and efficient dispersive liquid-liquid microextraction technique (DLLME) was developed by using a mixture of two solvents: 40 μL of tetrachlorethylene (extraction solvent) and 1.0 mL of methanol (disperser solvent), which was rapidly injected with a syringe into 10 mL of water sample. Some important parameters affecting the extraction efficiency, such as type and volume of solvents, water sample volume, extraction time, temperature, pH adjustment and salt addition effect were investigated. Simultaneous determination of 34 commonly used pesticides was performed by using gas chromatography coupled with mass spectrometry (GC-MS). The procedure has been validated in order to obtain the highest efficiency at the lowest concentration levels of analytes to fulfill the requirements of regulations on maximum residue limits. Under the optimum conditions, the linearity range was within 0.0096–100 μg L−1. The limits of detection (LODs) of the developed DLLME-GC-MS methodology for all investigated pesticides were in the range of 0.0032 (endrin)–0.0174 (diazinon) μg L−1 and limits of quantification (LOQs) from 0.0096 to 0.052 μg L−1. At lower concentration of 1 μg L−1 for each pesticide, recoveries ranged between 84% (tebufenpyrad) and 108% (deltamethrin) with relative standard deviations (RSDs) (n = 7) from 1.1% (metconazole) to 11% (parathion-mehtyl). This methodology was successfully applied to check contamination of environmental samples. The procedure has proved to be selective, sensitive and precise for the simultaneous determination of various pesticides. The optimized analytical method is very simple and rapid (less than 5 min).Graphical abstractAnalytical procedure for testing water samples consists of dispersive liquid-liquid microextraction (DLLME) and gas chromatography coupled with mass spectrometry (GC-MS).
Highlights
Pesticides are a numerous and diverse group of chemical compounds
The biggest challenge was the optimization step of the analytical procedure, in order to obtain the highest efficiency at the lowest concentration levels of analytes to fulfill the requirements of regulations on maximum residue limits
The obtained results may be the basis for improvement or upgrading of water treatment technologies, wastewater treatment and proper waste management. These values exceed the maximum permissible content of pesticides in waters established by the European Union, which is 0.1 μg L−1 for individual compounds [9,10,11]
Summary
Pesticides are a numerous and diverse group of chemical compounds. Nowadays, they are applied in many spheres of life, in agriculture [1, 2]. The range of applications is continually expanding; their consumption is ever increasing and more of them are getting into the environment [2,3,4]. The presence of pesticides, those highly soluble and polar, in different type of environmental samples has been reported [5,6,7]. One of the basic ways of limiting the adverse effects of pesticides on human health is the continuous monitoring of these compounds [1]. The numerous regulations that have come into force, on both national and EU level, concerning
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
