As mentioned previously, calconcarboxylic acid (or Patton-Reeder Indicator) is used for the determination of calcium ion concentration by complexometric titration.
Calconcarboxylic acid is a useful indicator for calcium titrations with EDTA in the presence of magnesium. It is also required for the staining of proteins in gels. Calconcarboxylic acid is also known as Patton-Reeder indicator and is used in the determination of calcium at pH 12.
PATTON AND REEDERS REAGENT AR