Biochemical Characterisation of the Leaf of Morinda Lucida: Prospects for Environmentally-Friendly Steel-Rebar Corrosion-Protection in Aggressive Medium

This paper employs atomic absorption spectroscopy (AAS), Fourier transform infrared spectroscopy (FTIR) and phytochemical screening methods for biochemical characterisation of the inorganic and organic constituents of the leaf of Morinda lucida. AAS results showed that this well-known medicinal-plant is high in iron (Fe = 5143.54 µg/g), low in cadmium (Cd = 2.9506 µg/g) and does not contain chromium (Cr). Also, Euclidean hit-list from the FT-IR instrument suggests Morinda lucida leaf-extract contains S-, N-, Br- and O- containing heteroatoms. The phytochemical analyses indicated presence of tannins, phlobatannins, saponins, flavonoids and terpenoids. These results bare prospects on suitability of leaf-extract from Morinda lucida for environmentally-friendly steel-rebar corrosion-protection in aggressive medium. Preliminary tests based on this showed that use of 0.083 wt% cement of Morinda lucida retarded steel-rebar total-corrosion and eventually reduced corrosion rate as admixture in duplicated 3.5% NaCl-immersed concretes, relative to control samples in the same medium.