Determination of nitrobenzenes and nitrochlorobenzenes in water samples using dispersive liquid-liquid microextraction and gas chromatography-mass spectrometry

Abstract

A rapid and sensitive method was developed for the determination of eight nitrobenzenes and four nitrochlorobenzenes in water. The method is based on dispersive liquid-liquid microextraction (DLLME) followed by gas chromatography-mass spectrometry (GC-MS). The key factors influencing the extraction efficiencies, including the nature and volume of the extraction and dispersion solvent and the ratios of the extraction solvent and dispersion solvent were examined and optimized. Under the optimized conditions, the method yields a linear correlation at a concentration range of 0.5 μg L⁻¹–500.0 μg L⁻¹ for all the target analytes with correlation coefficients (R²) of 0.9915 to 1.0000, and relative standard deviations (RSD, n = 6) of between 4.9% and 8.2%, depending on the compound analysed. In addition, good pre-concentration factors of 243 to 525 for each specific compound were achieved. These results suggest that the method presented herein is a rapid and powerful microextraction technique that is useful for the detection of these organic pollutants in water samples and is suitable for emergency monitoring.