Determination of benzimidazole pesticide residues in soil by ultrasound-assisted supramolecular solvent microextraction

The objective of this study was to develop a simple, rapid, and efficient pretreatment method using a supramolecular solvent as the extractant combined with high-performance liquid chromatography-ultraviolet to detect benzimidazole residues in environmental soil. The supramolecular solvent was composed of long-chain alcohols, tetrahydrofuran, and water in proportion, showing excellent solubility and polarity range, so a supramolecular solvent microextraction method was established. The optimum method was identified by optimizing the types of long-chain alcohols, the alcohol/tetrahydrofuran ratio, the pH, the amount of extractant, and the extraction time. The detection limits were 12.1-39.9 mu g/kg with a relative standard deviation between 1.2% and 3.2% (n = 6). The recoveries ranged between 56.6% and 86.1%, and the linear relationship was good. The correlation coefficient (r(2)) was 0.9843 - 0.9998. This method was then used to measure five benzimidazoles (thiabendazole, albendazole sulfone, ophendazole, albendazole, and fendazole) in soil samples.