Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Hydroxynaphthol Blue (1-(2-Naphtholazo-3,6-disulfonic acid)-2-naphthol-4-sulfonic Acid, Disodium Salt) 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 Hydroxynaphthol Blue provides, in addition to common physical constants, a general description including typical appearance and applications. The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Suitability for Calcium Determination.
C20H12N2O11S3Na2
Formula Wt 598.49
CAS No. 165660-27-5
Note: This reagent is deposited on crystals of sodium chloride. The small blue crystals are freely water-soluble. In the pH range between 12 and 13, the solution of the indicator is reddish pink in the presence of calcium ion and deep blue in the presence of excess (ethylenedinitrilo)tetraacetate.
GENERAL DESCRIPTION Typical appearance . . . . . . . . . . . . . . . . . . . dark blue solid Applications . . . . . . . . . . . . . . . . . . . . . . . . determination of calcium
SPECIFICATIONS Suitability for calcium determination . . . . . . . . Passes test
© 2017 American Chemical Society
A
DOI:10.1021/acsreagents.4171 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
TEST Suitability for Calcium Determination Dissolve 0.3 g in 100 mL of water, add 10 mL of 1 N sodium hydroxide volumetric solution and 1.0 mL of calcium chloride solution (1 g in 200 mL), and dilute with water to 165 mL. The solution should be reddish pink. Add 1.0 mL of 0.05 M (ethylenedinitrilo)tetraacetic acid, disodium salt. The solution should be deep blue.
© 2017 American Chemical Society
B
DOI:10.1021/acsreagents.4171 ACS Reagent Chemicals, Part 4
