Dissolvable Mg/Al layered double hydroxides and surfactant as an extractant for trace analysis of benzoylurea insecticides by high performance liquid chromatography.

A rapid and simple preconcentration method using dissolvable Mg/Al layered-double hydroxides (LDHs) and high performance liquid chromatography-photodiode array detection (HPLC-PDA) was developed for the analysis of benzoylurea insecticides (BUs) in water and honey samples. The proposed dissolvable LDHs for the extraction can be prepared in one step by the sequential addition of sodium hydroxide, magnesium chloride, aluminium chloride, and sodium dodecyl sulfate into the sample solution containing the target BUs. The co-precipitate phase was simply obtained after centrifugation, and the phase was then dissolved with formic acid before analysis by HPLC. The developed method provided an enrichment factor of 12.5-23.7. LODs were obtained in the range of 0.1-0.3 μg L-1 for deionized water, 0.2-2.0 μg L-1 for environmental waters, and 0.5-2.0 μg L-1 for the analyzed honey samples. Good recoveries ranging from 78.4 to 117.8% and 72.7 to 117.9% for water and honey samples, respectively, were obtained.