Field method for estimation of fluoride in drinking groundwater by photometric measurement of spot on aluminium quinalizarin reagent paper

Abstract

A simple field method for determination of fluoride in drinking water using handmade fluoride reagent paper impregnated by aluminium quinalizarin complex was developed. Fluoride reacts with the impregnated reagent paper to release the free ligand with new colour, orange different from that of the complex. The change in the colour, which is proportional to the amount of fluoride, was measured by the Arsenator. The functionality of the Arsenator which is based on a photometric measurement of spot on the reagent paper is expanded to analyse fluoride. The method allows a reliable determination of fluoride in the range 0.0–2.0 mg L−1. Further spectrophotometric determinations of fluoride showed that Beer’s law is obeyed in the range of 0.3–5.0 mg L−1 at 553 nm. Sensitivity, detection limit, quantitation limit, and the percentage recovery of 1.5 mg L−1 fluoride were found to be 0.117 μg mL−1, 0.1 mg L−1, 0.3 mg L−1, and 101.2 respectively.

Keywords

• Fluoride analysis
• Field method
• Drinking water
• Aluminium quinalizarin complex
• Impregnated paper
• Arsenator