Chemical Modification of Nanosilica Toward Dispersive Solid Phase Extraction of Trace Triazine Herbicides from Environmental Water Samples

An easy and fast pathway in preparation of organo-functionalized silica in nanosize range withphenyl-terminated group via co-condensation method is reported. Fourier transform infrared(FTIR) spectra confirmed the grafting process and scanning electron microscopy (SEM) imagecorroborated formation of nanosized material. Applicability of phenyl-modified nanosilica wasexamined as a sorbent in dispersive solid phase extraction (DSPE)of triazine herbicides. Theeffect of the different parameters affecting DSPE efficiency, such as sample pH, extraction time was studied. The amount of enrichment factors for triazines using proposed method were found in the range of 31-43. Calibration curves of triazines showed linearity in the range of 0.5-200,1.0-200, 1.5-200 and 2.0-1000 µg L-1 for analytes. In addition, the detection limits for theanalytes were in the range of 0.2-0.6 µg L-1. The values of relative standard deviation (RSD%)for n=3 at the concentration level of 10 µg L-1 were obtained lower than 3.5% for all analytes.The proposed method was also applied to the extraction of triazine herbicides from environmental samples and satisfactory relative recoveries were obtained.