Characterization of adsorbents from plant source (water leaf (Talinum Triangulare), bitter leaf (Vernonia Amygdalina) and vetiver grass (Vetiveria Zizanioides) using infrared spectrometric tecnnique

摘要

Powdered samples of Bitter leaf (PBL), Water leaf (PWL) and Vetiver grass (PVG) were analyzed with the use of Nicolet IS5 Fourier Transform Spectrometer to identify the functional groups present in these plants. Results obtained showed the presence of alcohol (OH-), alkane (C-C) and alkene (C=C) in all three plants as indicated by the peaks at wavelength ranges of 3600 - 3200cm-1, 2935 - 2915cm-1 and 1680- 1620cm-1 respectively. Tertiary alcohol and phenol were also present in all three plants as indicated in the wavelength ranges of 1420 - 1330cm-1 and 1390 - 1310cm-1 respectively. Carbonyl (C=O) and Nitro (N=O) functional groups were exclusively found in Bitter leaf at wavelength ranges of 1740 - 1715cm-1 and 1550 - 1500 cm-1 respectively while wavelength ranges of 1190 - 1130cm-1 and 1090 - 1020cm-1 indicates the presence of secondary and primary amines exclusively present in Bitter leaf and Vetiver grass. Functional groups such as sulfoxide (S=O) and iodo compounds (C-I) as indicated at wavelength ranges of 1070 - 1030cm-1 and 600 - 500cm-1 were present in Vetiver grass. The higher the molecular polarizability of the plants which is a function of the polar functional groups present, the higher the adsorption capacity of the plant. The presence of carbonyl functional groups in Bitter leaf will give it an advantage in terms of adsorption capacity compared to Water leaf and Vetiver grass because carbonyl functional groups are highly polarized due to their ability to form hydrogen bond as well as the presence of high dipole moments orchestrated by two electronegative atoms.