Reagent extracted from purple sweet potato was used to enable detection of Cu2+ in water by the naked-eye. The optimum conditions for this were determined by adding 10 mL of reagent to a mixture of 500 mL of buffer pH 7 (0.01 M) and a 200 mL water sample. The lowest concentration of Cu2+ able to be detected by the naked-eye was 3x10-4 M without any interfering effects. This method was validated by comparing Cu2+ concentration detected with the AAS technique. The results show that Cu2+ concentrations obtained from both techniques were similar.
Keywords: Purple sweet potato, Copper (II), Anthocyanin, Cyanidin, Naked-eye detection
Mikac-Dević, D. (1969). Micromethod for copper determination in serum and urine with 1,5-diphenylcarbohydrazide. Clinica Chimica Acta, 26(1), 127-130.
Khaodee, W., Aeungmaitrepirom, W., & Tuntulani, T. (2014). Effectively Simultaneous Naked-Eye Detection of Cu(II), Pb(II), Al(III) and Fe(III) Using Cyanidin Extracted from Red Cabbage as Chelating Agent. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 126, 98-104.
Kidmose, U., Edelenbos, M., Nørbæk, R., & Christensen, L. P. (2002). Colour stability in vegetables. In D. B. MacDougall (Ed.), Colour in food: Improving quality (pp. 179-232). Boca Raton: CRC Press.
Moncada, M. C., Moura, S., Melo, M. J., Roque, A., Lodeiro, C., & Pina, F. (2003). Complexation of aluminum(III) by anthocyanins and synthetic flavylium salts: A source for blue and purple color. Inorganica Chimica Acta, 356, 51-61.
Rein, M. (2005). Copigmentation reactions and color stability of berry anthocyanins. Helsinki, Russia: University of Helsinki.
Steed, L. E., & Truong, V.D. (2008). Anthocyanin Content, Antioxidant Activity and Selected Physical Properties of Flowable Purple-Fleshed Sweet Potato Purees. Journal of Food Science, 5, S215–S221
Ukwueze, N. N., Nwadinigwe, C. A., Okoye, C. O. B., & Okoye, F. B. C. (2009). Potentials of 3, 3’, 4’, 5, 7-pentahydroxyflavylium of Hibiscus rosa-sinensis L. (Malvaceae) flowers as ligand in the quantitative determination of Pb, Cd and Cr. International Journal of Physical Sciences, 4, 58-62.
Yoshida, K., Kitahara, S., Ito, D., & Kondo, T. (2006). Ferric ions involved in the flower color development of the Himalayan blue poppy, Meconopsis grandis. Phytochemistry, 67, 992-998.
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