text: Complexometric indicators are water-soluble organic molecules. Some examples are:
  * Calcein with EDTA for calcium
  * Patton-Reeder Indicator with EDTA for calcium with magnesium
  * Curcumin for boron, that forms Rosocyanine, although the red color change of curcumin also occurs for pH > 8.4
  * Eriochrome Black T for aluminium, cadmium, zinc, calcium and magnesium
  * Fast Sulphon Black with EDTA for copper
  * Hematoxylin for copper
  * Murexide for calcium and rare earths, but also for copper, nickel, cobalt, and thorium
  * Xylenol orange for gallium, indium and scandium