Air-assisted liquid–liquid microextraction for simultaneous derivatization, extraction, and preconcentration of some phenolic compounds

Abstract

In this study, an air-assisted liquid–liquid microextraction (AALLME) method has been developed for simultaneous derivatization, extraction, and preconcentration of some phenolic pollutants in aqueous samples before their determination by gas chromatography-flame ionization detection (GC-FID). In order to improve the chromatographic behavior of phenolic compounds, the analytes were derivatized with butyl chloroformate (BCF) and extracted simultaneously into 1,1,1-trichlorethane. The effects of different parameters influencing the extraction efficiency including extraction solvent type and its volume, ionic strength, volume of derivatization agent, and extraction numbers were investigated and optimized for the simultaneous derivatization/microextraction procedure. Under the optimum extraction conditions, the method showed wide linear ranges (LRs) between 1–2000 μg L⁻¹. The other analytical parameters were obtained in the following ranges: enrichment factors (EFs) 2020–2761, enhancement factors (EnFs) 2225–3807, extraction recoveries (ERs) 65–88%, and limits of detection (LODs) 0.1–0.4 μg L⁻¹. Relative standard deviations (RSDs) for the extraction of 100 and 200 μg L⁻¹ of each selected phenol (n = 6) were obtained in the ranges of 2–4% and 1–4%, respectively. Finally, the target phenols were determined in different samples such as tap water, river water, petrochemical wastewater, refinery wastewater, and municipality wastewater by the proposed AALLME-GC-FID method.