EXTRACTION AND ISOLATION OF ASCORBIC ACID FROM AUSTRALIAN PINE (Casuarina equisetifolia) NEEDLES GROWN IN JOS AND ENVIRONS.

Abstract

Ascorbic acid was extracted and isolated from the aqueous extract of Casuarina equisetifolia (Australian pine needles) harvested from the main campus, university of Jos, Nigeria. The extraction was carried out via cold extraction (maceration) while the isolation was done using gravimetric analysis. The isolated sample was identified using UV-Vis, FTIR, GC-MS and H-NMR spectrophotometric analysis. Fresh needles (leaves) of Casuarina equiselifolia which contains 61.00±1.6 mg/100g of ascorbic acid was used for this research when compared with related species within same environment. The proximate composition is moisture content (10.27±0.48) %, crude protein (5.98±0.20) %, Crude fibre (22.89±0.35) %, crude fat (3.72±0.24) %, ash (2.34±0.07) %, carbohydrate (54.81±0.27) % and ascorbic acid (61.00±1.60) mg/100g. The molar concentration of ascorbic acid in the sample was (0.02075±0.001) moldm-3 while the weight percent of the lyophilized isolate is (68.04g/500g, 13.608%). The UV-Vis determination gives peaks at 240nm (weak band) and 300nm (λmax). The FTIR spectrophotometric determination gave some distinctive peaks. For this research, only the OHs, the lactone C=O (around 1750 cm-1) and C=C stretch (approximately 1680 cm-1) bands will be considered. The four O-H bands observed in the isolated ascorbic acid 1.0 can be assigned as follows: C(1) – OH (3524.13, O-H stretch, free hydroxyl (alcohol)), C(4) – OH (3404.48,O-H stretch, H bonded (alcohol)), C(3) OH (3303.21, O-H stretch, H bonded (alcohol)), C(2) – OH (3022.28, OH stretch (carboxylic acid)) and the lactone C=O (1751.98 cm-1) and C=C stretch (1654.63 cm-1) bands. The GC-MS indentified Ethane dioic, dimethyl ester (100%) which has a molecular formula C4H6O4 (m/z118.0880) with base peak at m/z 8.0, with the possible loss of C2H2O2 (Acetolactone), a transient species of mass spectrometer. The H-NMR in methanol and deuterated DMSO (Dimethyl sulphoxide) identified the presence of the most deshielded proton and the most acidic proton. There was partial decomposition from the confirmatory titrimetric analysis (56.88% ascorbic acid). The FTIR analysis confirms that the compound isolated is ascorbic acid and further confirmation derived from the UV-Vis. The result of this research should be adopted for the mass production of high quality ascorbic acid in Nigeria.