UV/visible Spectroscopic Studies and Analytical Evaluation of Dicliptera verticillate Leaves Extracts as Eco-friendly Indicator for Acid-Base Titration

Abstract

Synthetic indicators usually employed in acid-base titration to determine the end point is expensive and non-biodegradable. Hence there is need to develop an eco-friendly and cost effective acid-base indicator from plant origin to serve as efficient alternative for the synthetic indicators. This research work focused on the development of easily available, cost effective and eco-friendly indicator from Dicliptera verticillate leaves extracts for acid-base titration. UV/visible spectrometer was used to analyzed the ethanol extract (EE), ethanol extract in basic medium (EEB), ethanol extract in acidic medium (EEA), hot water extract (HWE), Hot water extract in basic medium (HWEB) and hot water extract in acidic medium (HWEA) to determine the wavelength of maximum absorption (λmax), and the absorbance of the extracts in different media in order to evaluate the chromophoric properties of the plant extracts phytochemicals before and after titrations. Titrimetric analysis was carried out in the reactions of strong acid/strong base (HCl/NaOH), strong acid/weak base (HCl/NH4OH), weak acid/strong base (CH3COOH /NaOH) and weak acid/weak base (CH3COOH/NH4OH). The results revealed that both extracts exhibit hypsochromic shift (shift to a shorter wavelength) with corresponding hypochromic effect (decreased in the absorption intensity) in both acidic and basic media. The titrimetric results revealed that the plant extracts give the end point comparable to that of the synthetic indicators such as methyl orange and phenolphthalein. Hence ethanol and hot water extracts of Dicliptera Verticillate can be utilized as suitable alternative indicators for acid - based titrations, since it is biodegradable and cost effective.