Chemical Name: 2-(5-Bromo-2-pyridylazo)-5-[N-n-propyl-N-(3-sulfopropyl)amino]aniline, sodium salt
Appearance: reddish-orange or orange powder
Molar Absorptivity: ≥86,000 at 558 nm
Absorbance: ≥0.400 (around 458 nm)
MW: 478.34, C17H21BrN5NaO3S
Storage Condition : ambient temperature
Shipping Condition : ambient temperature
5-Br-PSAA is a water-soluble colorimetric reagent for Fe(II) and Co(III) detection. This reagent forms colored complexes with Fe, Ni, Cu, and Co, but not with Zn. The Fe(II) and Co(III) complexes are very stable, and even EDTA cannot remove metals from these complexes. However, Cu(II) and Ni(II) complexes are decomposed by EDTA, so 5-Br-PSAA can be used to determine Fe(II) in the presence of Cu(II) or Ni(II). The molar absorptivity of Fe(II) is reported to be 8.9x104 (λmax=558 nm). The 5-Br-PSAA assay is 4 times as sensitive as Bathophenanthroline assay. Dr. Sakai and others determined ppb levels of Pb (ε=98,400) using 5-Br-PSAA by flow injection analysis. Dr. Makino and others determined Cu(II) in 0.2 ml of serum by direct colorimetric detection (λmax=580 nm, ε=64,000).
1. D. Horiguchi, et al., Water-soluble Pyridylazo Reagents for the Spectrophotometric Determination of Metals Determination of Iron(II) with 2-(5-Bromo-2-pyridylazo)-5-(N-propyl-N-sulfopropylzmino)aniline. Anal Chim Acta. 1983;151:457-463.
2. T. Sakai, et al., Flow-injection Spectrophotometric Determination of Palladium in Catalysts and Dental Alloys with 2-(5-Bromo-2-Pyridylazo)-5-(NPropyl-N-Sulfopropylamino)Aniline. Anal Chim Acta. 1988;214:271-277.
3. T. Makino, A Sensitive, Direct Colorimetric Assay of Serum Copper Using 5-Br-PSAA. Clin Chim Acta. 1989;185:7-16.
4. S. W. Kang, et al., Simultaneous Spectrophotometric Determination of Iron and Copper in Serum with 2-(5-Bromo-2-pyridylazo)-5-(N-propyl-Nsulphopropylamino)aniline by Flow-injection Analysis. Anal Chim Acta. 1992;261:197-203.