Arsenazo III test strip for rapid detection of hardness of water

252-254In this article development and optimization of visually evaluable dry-reagent test strip technique for qualitative and semi-quantitative estimation of hardness of water has been described. The hardness of water is based on its alkaline earth content i.e. calcium and magnesium ions and their salts. The estimation of hardness of water in industry as well as in private sector is essential. Presently, calorimetric assay and test kit methods are commonly used, however, they are expensive and require trained persons to perform the test. The dry reagent strip developed in the laboratory is quick, simple and economical. It is based on specific chromogen immobilized on to a pad which reacts with calcium present in water and thereby changes the colour of the strip from purple to blackish blue. The change in colour is visible with naked eyes and can be compared with the colour chart