Abstract

Maynard O. Galingana and  Voltaire G. Organo*

DOI : http://dx.doi.org/10.13005/ojc/320308

A simple, “green” and colorimetric  approach in differentiating various anions is presented. Acidified ethanolic extracts from flowers of Anthurium andreanum undergo color changes in the presence of HSO₄^-, CH₃COO^-, C₆H₅COO^-, HCO₃^-, CO₃^2-, HPO₄^2- and PO₄^3- anions in aqueous solutions. Anionic acid-base conjugate pairs such as HCO₃^- and CO₃^2-, HSO₄^- and SO₄^2-, and phosphates H₂PO₄^-, HPO₄^2-, and PO₄^3- can also be discriminated from each other.  Visible spectroscopic analysis indicates possible structural changes in pigments due to pH change of solution as a consequence of the basic property of anions.

colorimetric;Anthurium andreanum extracts;anion recognition;flower pigments

[ View HTML Full Text]