Acid Alizarin Black SN indicator (Mordant Black 25)

Product name:Acid Alizarin Black SN indicator (Mordant Black 25)

Product Description:The metallochromic properties of the closely related tris-hydroxy bis-azo dyestuffs Acid Alizarin Black-SN and-SE are examined. The former is shown to be a particularly excellent complexometric indicator for calcium in dilute solution and is also recommended for strontium, manganese, nickel, zinc, cadmium and thorium. Both indicators are shown to form 2:1 indicator-calcium chelates, on the basis of spectrophotometric evidence, and the unusual behaviour of the former indicator in strong calcium solutions is explained.