| 摘要 |
<p>Chelant residual or deficiency in water containing divalent calcium and magnesium hardness ions with or without heavy metal ions is determined photometrically by adding to the water a solution comprising the salt of a hardness ion and a second chelating agent, said agent having a higher affinity for heavy metals than the chelant to be measured, and then adding a solution of Calmagite dye, and then reading the change in absorbance of the dye solution with the photometer.</p> |
