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

MARÍA FLORENCIA JOFRÉ; MARÍA FERNANDA SILVA; ANA C. COHEN; FEDERICO GÓMEZ

Mendoza

Simposio; 24thLatin-American Symposium on Biotechnology, Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis and Microchip Technology; 2018

LACE 2018

The many functions of melatonin (MT) and its major role in the protection of plants underdifferent stress conditions has inspired new investigations using beneficial bacteria,collectively referred as Plant Growth Promoting Rhizobacterias (PGPRs), as another possiblesource of MT. In this work, a robust, reliable, low-cost, quick and simple method based onNatural Deep Eutectic Solvents (NADES) modified capillary zone electrophoresis (CZE) forthe extraction, preconcentration and simultaneous determination of melatonin, tryptophan andserotonin in plant material and bacterial cultures is proposed. Extraction of indole compoundsfrom plant tissues was enhanced by ultrasound and solid phase extraction, which was carriedout 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), 2% ofNADES 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. Underthe optimal conditions, a successful application on Arabidopsis tissue and bacterial cultureconfirmed the validity of this method as a tool to contribute to the elucidation of the biologicalrole of melatonin in plants and microorganism.