Natural Deep Eutectic Solvents (NADES) modified Capillary Zone Electrophoresis for the determination of melatonin and its precursors.

JOFRÉ, M. FLORENCIA; SILVA, M. FERNANDA; COHEN, ANA CARMEN; GOMEZ, FEDERICO

Mendoza

Simposio; LACE- 24th Latin American Symposium; 2018

IBAM-CONICET

The many functions of melatonin (MT) and its major role in the protection of plants under different stress conditions has inspired new investigations using beneficial bacteria, collectively referred as Plant Growth Promoting Rhizobacterias (PGPRs), as another possible source of MT. In this work, a robust, reliable, low-cost, quick and simple method based on Natural Deep Eutectic Solvents (NADES) modified Capillary Zone Electrophoresis for the extraction, preconcentration and simultaneous determination of melatonin, tryptophan and serotonin in plant material and bacterial cultures is proposed. Extraction of indole compounds from plant tissues was enhanced by ultrasound and solid phase extraction, which was carried out with miniaturized C8 SPE homemade cartridges. The use of NADES modified CZE, enabled us to reach adequate selectivity. A BGE of 10 mM sodium tetraborate (pH 9.2), 1% of NADES made of Lactic acid, glucose and H2O, allowed baseline separation in less than 15 min. The proposed methodology provided limits of detection (LODs) down to low ppb levels. Under the optimal conditions, a successful application on Arabidopsis tissue and bacterial culture confirmed the validity of this method as a tool to contribute to the elucidation of the biological role of melatonin in plants and microorganism.