Optimization and application of ultrasound-assisted sugar based deep eutectic solvent dispersive liquid-liquid microextraction for the determination and extraction of aflatoxin M1 in milk samples

This study presents an ultrasound-assisted sugar based deep eutectic solvent dispersive liquid-liquid micro-extraction procedure (UA sugar-DES DLLME) for the extraction of aflatoxin M-1 (AFM(1)) in milk samples prior to its determination by UV-VIS spectrophotometer. Also, in this approach, different sugar based deep eutectic solvents were prepared and their ability in extraction and separation of the AFM(1) from the samples were investigated. The UA sugar-DES DLLME procedure consists of three steps. In the first step, pyrogallol and sugar based-DES solutions were added to the sample solution at pH 3.8. In the second step, ultrasound was applied to the solution obtained and the AFM(1) were extracted into the UA sugar based-DES phase. In the final step, the resulting mixture was centrifuged and the sediment phase was separated from the mixture. After the micro-extraction, the sediment phase was analyzed at 279 nm by UV-VIS spectrophotometer. In order to obtain reli-able, accurate and precise analytical results, the effective microextraction parameters were investigated and optimized using response surface methodology. Under optimum conditions, detection limit, extraction recovery, and enrichment factor were 6.1 ng L-1, 91 +/- 3-107 +/- 6%, and 328, respectively. Intraday and inter-day studies were performed at concentrations of 50, 100 and 200 ng L-1 of the AFM(1) for the precision of the UA sugar-DES DLLME procedure. The intraday and inter-day precision results ranged from 3.3 to 5.1% and 4.1-6.2%, respectively. Also, it was successfully used for determination of the selected milks.