Development of a natural dispersive liquid–liquid micro-back-extraction technology based on hydrophobic deep eutectic solvent for the enrichment and determination of heavy metals in soy sauce

This work develops a novel microextraction-back-extraction technique for detecting Pb and Cd in soy sauce. This method employs acidic hydrogen peroxide to dissociate Pb/Cd-DDTP complexes and transfer the analytes into the aqueous phase for GFAAS.