Appearance Light grey powder
PH 3.8(yellow-green)~5.4(blue)
Maximal absorbing waelength,nm
λ1(Ph3.8)
λ2(Ph5.4)
440~445
615~618
Quality absorption coefficient,L/cm.g
α1(λ1,Ph3.8, dry base)
α1(λ1,Ph3.8, dry base)
24-28
53-58
Ethanol solution testing Pass
Residue on iginition 0.25% max
Loss on drying 3.0% max