PREPARATION OF ACID – BASE INDICATORS USING Curcuma longa (TUMERIC) RHYZOMES

Abstract

Reagent indicators are substances mostly weak acids which by changing color, show whether solutions or substances are acidic or alkaline or/ and qualitatively identify analytes. They are usually imported into Nigeria hence expensive. Yellow turmeric papers are reddish-brown under alkaline conditions and reddish-brown turmeric papers are yellow under acidic conditions. Yellow and reddish-brown tumeric solutions were prepared. Respective pH of the turmeric solutions was 9.2 (for the reddish-brown turmeric solution and 4.3 (for the yellow turmeric solution). Reddish-brown and yellow turmeric papers were prepared; performances of the prepared turmeric papers were evaluated relative to standard litmus papers (SLP): yellow turmeric paper, 97.37 %; reddish-brown turmeric papers, 96.49 %. These indicators were packaged and labeled.