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Item # Unit Size
1 g
10 g

For Research Use Only Products

Application: Metal indicator, heavy metal ion detection
Chemical Name: 1-(2-Pyridylazo)-2-naphthol
CAS: 85-85-8

Appearance: Yellowish or reddish orange crystalline powder
Absorbance (0.040 mmol/l): ≥0.600 (around 470 nm)
MW: 249.27, C15H11N3O

Storage Condition: ambient temperature, protect from metal
Shipping Condition: ambient temperature

Product Description
PAN is a metal indicator and colorimetric reagent for heavy metal and rare earth metal ions. This reagent is slightly soluble in acidic solutions and soluble in alkaline solutions. Its proton dissociation constants are reported to be pKa1=2.9 and pKa2=11.6 (μ=0.1, NaClO4, at room temperature). The aqueous solution is yellow at pH<12 and red at pH>12. The distribution constants, logKD, of chloroform/water and carbon tetrachloride/water are reported to be 5.4 and 4.0, respectively.

Chemical Structure

Chelate titration: Bi, Cd, Ce, Cu, Ga, In, TI, UO2(II), Zn
Solvent extraction colorimetru: Ag, Bi, Cd, Co, Cr, Cu, Fe, Ga, Hf, Hg, In, Ir, Mn, Nb, Ni, Os, Pd, Pt, Rh, Ru, Sb, Ti, Tl, UO2(II), VO(II), Zn, Zr, rare earth metals
1) S. Shibata, Solvent Extraction Behavior of Some Metal-1-(2-Pyridylazo)-2-naphthol Chelates. Anal Chim Acta. 1960;23:367-369.
Table 1 Characteristics of PAN Metal Complex

* M=metal ion, L=PAN

Table 2 Photometric Detection Conditions Using PAN