Application: Alkaline earth metals detection, colorimetric

 
MSDS
ChemicalName: 2,7-Bis(4-chloro-2-phosphonophenylazo)-1,8-dihydroxy-3,6-naphthalenedisulfonic acid
CAS:
1914-99-4

Appearance: Reddish brown or black purple crystalline powder
Absorbance (0.018 mmol/l): ≥0.530 (around 550  E570 nm)
MW: 757.37
, C22H16Cl2N4O14P2S2

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

Product Description
Chlorophosphonazo-III is a colorimetric reagent for thorium, uranium, lanthanoids, actinoids, and alkaline earth metals. This reagent is readily soluble in water and is violet at pH 4 or lower, blue in NaOH solution, and brilliant green in acids such as H2SO4, HCl and diluted HNO3 (it decomposes in concentrated HNO3). Its proton dissociation constants are reported to be -1.1, -1.1, 0.6, 0.8, 1.5, 2.5, 5.47, 7.20, 12.15 and 15.13 (μ=0.1, 20ºC). Chlorophosphonazo-III is used as a selective colorimetric reagent for calcium in a mixed Ca/Mg sample in the pH range of 2-3. It is also a useful indicator for the precipitation titration of SO42- using Ba2+ as a standard solution.

Chemical Structure


References
1. L. R. Snyder, et al., Characterization and Routine Determination of Nonbasic Nitrogen Types in Cracked Gas Oils by Linear Elution Adsorption Chromatography. Anal Chem. 1964;36:767-773.
2. J. W. Ferguson, et al., Simultaneous Spectrophotometric Determination of Calcium and Magnesium with Chlorophosphonazo-III. Anal Chem. 1964;36:796-799.
3. D. S. Howell, et al., Ultramicro Spectrophotometric Determination of Calcium in Biologic Fluids. Anal Chem. 1966;38:434-438.
4. T. Yamamoto, Extraction-photometric Determination of Uranium(IV) with Chlorophosphonazo-III. Anal Chim Acta. 1973;65:329-334.
5. M. Zenki, et al., Repetitive Determination of Calcium Ion and Regeneration of a Chromogenic Reagent Using Chlorophosphonazo III and an Ion Exchanger in a Circulatory Flow Injection System. Anal Sci. 2002;18:1137-1140.
Table 1 Metal Detection Conditions Using Chlorophosphonazo-III


Code# Unit Size Ships in* Price Quantity
C010-10
100 mg
8-14 business days $40.00
C010-12
1 g
8-14 business days $234.00

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