Tetrasodium EDTA is often preferred for the thermometric complexometric titration of metals because its solubility is much higher than the normally used dibasic salt Na2H2EDTA. The sample solution is buffered at pH ~10 using ammonia/ammonium chloride, and the exothermic reaction between the metal and amine buffer is used for endpoint determination. This Application Note explains how to use magnesium to standardize tetrasodium EDTA titrant.
