Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Murexide (5,5′-Nitrilobarbituric Acid Monoammonium Salt)
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Part 4, Monographs for Reagent Chemicals: General Descriptions, Specifications, and Tests eISBN: 9780841230460 Tom Tyner Chair, ACS Committee on Analytical Reagents James Francis Secretary, ACS Committee on Analytical Reagents
ABSTRACT This monograph for Murexide provides, in addition to common physical constants, a general description including typical appearance, applications, and aqueous solubility. The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Suitability as a Complexometric Indicator.
C8H8N6O6 (anhydrous) Formula Wt 284.20 C8H8N6O6 • H2O (monohy- Formula Wt 302.22 drate)
CAS No. 3051-09-0 CAS No. 6032-80-0
Note: This material is available in anhydrous and monohydrate forms. The tests are identical for both forms.
GENERAL DESCRIPTION Typical appearance . . . . . . . . . . . . . . . . . . . purple-red solid with green metallic luster Applications . . . . . . . . . . . . . . . . . . . . . . . . indicator Aqueous solubility . . . . . . . . . . . . . . . . . . . . sparingly soluble in cold water; moreso in hot
SPECIFICATIONS Suitability as a complexometric indicator . . . . . Passes test
© 2017 American Chemical Society
A
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4234 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
TESTS Suitability as a Complexometric Indicator
Downloaded by CORNELL UNIV on May 19, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4234
Dissolve 0.1 g in 100 mL of water. Add 1 mL to 100 mL of water, then add 10 mL of pH 10 ammoniacal buffer solution, and divide into two equal portions, A and B. Titrate portion A with nickel ion (Ni) standard solution until the blue component of the color is discharged. The color of the solution should change from purple to red. Use portion B as a control. The purple color is restored by adding 0.1 mL of 0.1 M EDTA volumetric solution. Portion A should match portion B in appearance.
© 2017 American Chemical Society
B
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4234 ACS Reagent Chemicals, Part 4
