Implementing a superhydrophobic substrate in immersed solvent-supported microextraction as a novel strategy for determination of organic pollutants in water samples.

In this research, a new approach for extraction and determination of polycyclic aromatic hydrocarbons from sea and rain water samples was developed by implementing a superhydrophobic substrate and consuming the least amount of solvent. This version of solvent-supported microextraction enabled us to perform the procedure in the immersion mode with the slightest troubles arising from water leakage into the gas chromatography. The superhydrophobic property leads to the fixation of extracting solvent on the substrate surface during water sampling. To prepare a superhydrophobic substrate, a piece of melamine foam was coated by tannic acid and silica nanoparticles using methyltrimethoxysilane and tetramethyl orthosilicate. The morphology of the prepared foams was studied by scanning electron microscopy. The developed solvent-supported microextraction method in combination with gas chromatography-mass spectrometry was applied to the isolation and determination of some typical polycyclic aromatic hydrocarbons from aquatic media. Influential parameters such as substrate nature, extractive solvent, eluting solvent and its quantity and extraction time were investigated. The limits of detection and quantification of the method under the optimized conditions were 0.01-0.11 µg L-1 and 0.03-1.01 µg L-1 , respectively. The relative standard deviations at the concentration level of 20 µg L-1 were between 3% and 14% (n = 3). The linearity of calibration curves ranged from 0.03 to 60 µg L-1 . The implementation of the solvent-supported method to the analysis of real water samples was quite successful and the relative recoveries were between 88% and 107%.