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