Green analytical method based on salt assisted graphene oxide dispersive solid phase extraction of symmetrical triazine herbicides in environmental water samples for liquid chromatographic determination

Graphene oxide (GO) was used as sorbent in dispersive solid phase extraction (DSPE) to enrich and extract some triazine herbicides from environmental water samples. It can form dispersed colloids in aqueous phase and provides rich functional groups for the formation of hydrogen bonding or pi-pi electrostatic interaction with benzene ring organic compounds containing oxygen and nitrogen functional groups. GO was synthesised by modified Hummers method and characterised with Fourier transform infrared (FT-IR) spectroscopy. As complete collection of GO after adsorption process is difficult task, in this established salt-assisted (SA)-GO-DSPE method, it was found to be aggregated and centrifuged in the presence of NaCl. The optimum value for main parameters that influenced extraction efficiency were investigated. Under the optimised conditions, low limits of detection (LODs) (0.12-0.80 ng mL (-1)), limits of quantification (LOQ) (0.4-2.68 ng mL (-1)), and good extraction recoveries (69.06-95.53%) were obtained for simultaneous extraction of simazine (SIZ), atrazine (ATZ), propazine (PRZ)) and prometryn (PRN). The relative standard deviations (RSD) of intraday (n = 6) and interday (n = 9) precisions were 2.54 to 5.84% and 4.38 to 8.56%, respectively. At the end, the applicability of the method was evaluated and target analytes were not detected in real samples. The proposed method is environment friendly and promising for trace analysis of pesticides including the target herbicides in environmental water samples.