Alkanol-based supramolecular solvent microextraction of organophosphorus pesticides and their determination using high-performance liquid chromatography

A sensitive method for extraction and determination of three organophosphorus pesticides (chlorpyrifos, diazinon, phosalone) using a supramolecular solvent (SUPRAS) made of inverted hexagonal aggregates of alkanol and high-performance liquid chromatography with ultraviolet detection (HPLC–UV) was developed. The studied factors were alkanol amount, THF percentage (v/v), pH and vortex time. According to the full factorial design results, the effective parameters were alkanol amount, THF percentage (v/v) and pH. Then, a CCF was applied to obtain optimal conditions. The optimized conditions were obtained at 100 mg of alkanol, 5% of THF and pH 3.9. The limits of detection of pesticides were 0.5–1.3 ng/mL. The linearity was 1.6–500.0 ng/mL for different pesticides. Relative standard deviations for intra- and inter-day extraction of pesticides were 3.3–5.0 and 5.1–6.3, respectively, for five measurements. The method was also successfully applied for the determination of the pesticides in fruit juice and tap water samples.