15 Chromogen/Metal Indicator



Metal Indicator

  • Product code
    M011  Murexide
  • CAS No.
  • Chemical name
    Purpuric acid, ammonium salt
  • MW
Unit size Price Item Code
5 g M011-10
25 g M011-12

Product Description of Murexide and MX

MX is a 1:250 mixture of Murexide and potassium sulfate. Murexide is a metal indicator for Ca, Co, Cu, Ni, Th, and rare earth metals; it is also a colorimetric reagent for calcium and rare earth metals. Murexide is slightly soluble in water, alcohol, and ether. Murexide is unstable in aqueous solution. Its proton dissociation constants are reported to be pKa1=0, pKa2=9.2 and pKa3=10.5. The solution is yellow in strong acidic conditions, reddish-purple in weak acidic conditions, and bluepurple in alkaline conditions. Detection conditions for calcium are pH 11.3, maximum wavelength 506 nm and detection range 0.2-1.2 ppm.

Chemical Structure


Open References

1) H. Gordon and G. Norwitz, "Spectrophotometric Determination of Calcium in Zirconium Powder by Use of Murexide", Talanta, 1972, 19, 7. 
2) K. S. Balaji, S. D. Kumar and P. Gupta-Bhaya, "Stability Constants of Calcium and Lanthanide Ions with Murexide", Anal. Chem.1978, 50, 1972.

Handling and storage condition

Appearance: Reddish to dark reddish purple powder
Solubility in water: To pass test (clear, reddish purple)
Absorbance: ≧ 0.200 (around 525 nm)
Sensitivity: To pass test
Sulfated ash: ≦ 0.20 %
IR spectrum: Authentic
Handling and storage condition
Ambient temperature

Product Classification

Product Classification

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