Application of elevated temperature-dispersive liquid-liquid microextraction for determination of organophosphorus pesticides residues in aqueous samples followed by gas chromatography-flame ionization detection

• An ET-DLLME method has been proposed for determination of OPPs in aqueous samples.
• It is simple and effective sample preparation technique for OPPs.
• EFs of the method were in the range of 1600–2075.

In the present study, an elevated temperature, dispersive, liquid-liquid microextraction/gas chromatography-flame ionization detection was investigated for the determination, pre-concentration, and extraction of six organophosphorus pesticides (malathion, phosalone, dichlorvos, diazinon, profenofos, and chlorpyrifos) residues in fruit juice and aqueous samples. A mixture of 1,2-dibromoethane (extraction solvent) and dimethyl sulfoxide (disperser solvent) was injected rapidly into the sample solution heated at an elevated temperature. Analytical parameters, including enrichment factors (1600–2075), linearity (r > 0.994), limits of detection (0.82–2.72 ng mL−1) and quantification (2.60–7.36 ng mL−1), relative standard deviations (<7%) and extraction recoveries (64–83%), showed the high efficiency of the method developed for analysis of the target analytes. The proposed procedure was used effectively to analyse selected analytes in river water and fruit juice, and diazinon was found at ng mL−1 concentrations in apple juice.