How one can test the strength of a sequestering or chelating agent?
We can test the strength of a chelating agent by a simple method! – (Volumetric Estimation of Sequesteriing Agents) Make a solution of Calcium Carbonate or Calcium Sulphate in distilled water. Say for example dissolve 500 mg of Analar grade Calcium Carbonate in pure distilled water of 1 liter. So you have prepared a known solution of 500 ppm of hardness. Ascertain the hardness by regular EDTA and Erchrome Black indicator method. Now take a 10ml micro-burette and fill it with the solution of Sequestering agent. Titrate and find out the end point. If 5 ml of a particular brand of sequestering agent is required to treat 1 liter of 500 ppm water, then the Chelating value (CV) of this sequestering agent is 1. If 1 ml if enough to reach end point the CV is 5. Normally the textile sequestering agents are supplied with CV of 1 to 3 and priced accordingly. Some more reference about Sequestering Agents: .Chelating agents are used to eliminate water hardness and heavy metals, such as iron and cop
