Application of supramolecular solvent-based dispersive liquid–liquid microextraction for trace monitoring of lead in food samples

Abstract

In this study, an efficient sample treatment method based on supramolecular solvent-based dispersive liquid–liquid microextraction (SM-DLLME) was applied for trace monitoring of lead by flow injection flame atomic absorption spectrometry. A supramolecular solvent comprising reverse micelles of 1-decanol in tetrahydrofuran (THF) was created by injection of these solvents into the aqueous sample solution. After injection of 1-decanol : THF mixtures into the sample solution, nanomicelles were produced in an ultrasonic bath and the lead–dithizone complex was extracted to the supramolecular phase at optimized pH. The solution was centrifuged and the metal complex formed was extracted into the supramolecular solvent phase. The detection limit for lead ions was 0.4 μg L⁻¹ under the optimized separation conditions. The relative standard deviations for six extraction analysis of 3, 10 and 100 μg L⁻¹ of lead ions were 4.8%, 4.5% and 4.1%. Finally, SM-DLLME was successfully applied for trace monitoring of lead ions in agricultural and food samples.