Simultaneous extraction of permethrin diastereomers and deltamethrin in environmental water samples based on aperture regulated magnetic mesoporous silica

Abstract

The aperture of KIT-6 can influence the recoveries of magnetic solid phase extraction. In this context, aperture regulated magnetic KIT-6 was prepared and characterized to improve the performance in the detection of deltamethrin and permethrin diastereomers. The novel Fe₃O₄@SiO₂@KIT-6/130 °C nanocomposite was selected for the extraction of pyrethroid insecticides including deltamethrin, cis-permethrin and trans-permethrin. The variables influencing the extraction process such as the material dosage, adsorption time, pH, salinity of the solution, desorption solvent and enrichment factor were evaluated. The method has the advantages of low LODs, a wide linear range, good reproducibility and acceptable recoveries. Under the optimal conditions, the recoveries are between 88.5% and 95.4%. The adsorption process corresponds well with pseudo-second order kinetics and Langmuir adsorption isotherms. The process is spontaneous and exothermic on the basis of thermodynamic records. Magnetic solid phase extraction coupled with high performance liquid chromatography based on the Fe₃O₄@SiO₂@KIT-6/130 °C nanocomposite offers an easy and sensitive way to detect trace pyrethroid insecticides in environmental water samples.