15 Chromogen/Metal Indicator

Calcein Blue

Calcein Blue

Metal Indicator

  • Product code
    C002  Calcein Blue
  • CAS No.
  • Chemical name
  • MW
Unit size Price Item Code
1 g $85.00 C002-08
1 g
Quantity may be adjusted within the cart.

Product Description

Calcein Blue is a fluorescent metal indicator in EDTA titration. It is highly soluble in alkaline solutions, but slightly soluble in water. Its proton dissociation constants are reported to be pKa1=2.45, pKa2=7.24 and pKa3=11.3. Calcein Blue solution emits bright blue fluorescence (λem=445 nm) at pH 4-11, but no fluorescence at pH 12 or higher. The blue fluorescence of the Calcein Blue solution at pH 4-11 is quenched by metal ions such as Co, Cu, Mn, Ni, and Pb. However, Calcein Blue forms a highly fluorescent complex with alkaline earth metals at pH 12 or higher. Since the endpoint of the chelate titration is clear by UV irradiation at 200-370 nm in a dark room, highly stained samples can be used. Calcein Blue is also suitable to determine Fe and Zr ions. Calcein Blue-Zn chelate can detect 10 ppb of F-. Calcein Blue aqueous solution emits laser at 449-490 nm. 


Chemical Structure


Open References

1. D. H. Willkins, Calcein Blue – A New Metalfluorechromic Indicator for Chelatometric Titrations. Talanta. 1960;4:182-184.
2. J. H. Eggers, Umbellikomplexon Und Xanthokomplexonein Beitrag zur Kenntnnis Komplexometrischer Fluoreszensindikatoren. Talanta. 1960;4:38-43.
3. H. N. Elsheimer, Complexometric Determination of Gallium with Calcein Blue as Indicator. Talanta. 1967;14:97-102.
4. M. A. Salam Khan, et al., A Structural Study of the Methyleneiminodiacetic Acid Derivatives of Some 7-Hydroxycoumarins. Anal Chim Acta. 1968;43:153-156.
5. R. V. Hems, et al., Spectrofluorimetric Determination of Submicrogram Amounts of Zirconium with Calcein Blue. Anal Chem. 1970;42:784-787.
6. T. L. Har, et al., Spectrofluorimetric Determination of Traces of Fluoride Ion by Ternary Complex Formation with Zirconium and Calcein Blue. Anal Chem. 1971;43:136-139.
7. T. Imasaka, et al., Characteristics of Coordination Compounds of Calcein Blue for a Tunable Oraganic Liquid Laser. Bull Chem Soc Jpn. 1976;49:2687-2695.
8. K. A. Matsoukas, et al., Spectrofluorimetric Determination of Magnesium in Blood Serum with Calcein Blue. Anal Chim Acta. 1989;227:211-218. 

Handling and storage condition

Appearance: White to pale yellow powder
Solubility in NaOH solution: To pass test (clear, colorless or yellow)
Sensitivity: To pass test
Sulfated ash: ≦ 0.50 %
IR spectrum: Authentic
Handling and storage condition
Ambient temperature

Product Classification

Product Classification

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