Dados do Trabalho

Título

Development of a natural deep eutectic solvent (NADES) dispersive liquid–liquid microextraction for determination of herbicides in derived foods from sugarcane

Introdução

Brazil is the world's largest exporter of ethanol and sugar, products derived from sugar cane. Additionally, sugarcane is a key ingredient in various foods consumed nationwide, such as fresh sugarcane juice, known as garapa, is a popular energy drink extracted by crushing sugarcane, rapadura, a candy similar to brown sugar and sugarcane syrup, also known as melado. Weed control is absolutely essential, as production losses due to this issue can range from 74.1% to 90.5%, In Brazil diuron (DIU), ametrine (AME) and tebuthiuron (TBT) are make up 70% of all herbicides utilized in sugarcane cultivation. Therefore, this study focuses on developing a new, quick, simple, and eco-friendly dispersive liquid–liquid microextraction based on natural deep eutectic solvent (NADES-DLLME) for the preconcentration of AME, DIU and TBT. The developed method will be used to analyze foods derived from sugarcane.

Material e Métodos

Simultaneous extraction and pre-concentration experiments were carried out, with the sample having a concentration of 100 µg L-1 of each herbicide and 10% (m/v) of NaCl, 0,1 mol L-1 BR Buffer, the volume was adjusted to 40 mL with ultrapure water and maintained at pH 6,5, in a 40 mL microextraction centrifuge tube. The extraction was carried out using 100 µL of NADES composed of menthol and acetic acid (2:1 molar ratio), where vigorous agitation was carried out for 1 min and subsequent centrifugation at 3000 rpm for 1 min. Afterwards, approximately 20 µL of the supernatant was collected and diluted in a ratio of 2:1 (v/v) in 99% methanol and injected into the HPLC-DAD.

Resultados e Discussão

The parameters that most affected the extraction were the volume of NADES, the pH of the medium and the salting out effect. The method was applied with recoveries ranging from 94 to 108%, where samples of sugarcane juice were doped with concentrations of 50 - 250 ug L-1 and samples of rapadura and melado doped with 250 – 500 ug Kg-1.

Conclusão

The method developed for determining herbicides via HPLC-DAD boasts several benefits, such as high analytical sensitivity, simplicity, and the use of solvents that align with green chemistry principles. It is suitable for application to complex foods matrices.