Monograph pubs.acs.org/doi/book/10.1021/acsreagents
o-Tolidine Dihydrochloride (3,3′-Dimethyl-[1,1′-biphenyl]-4,4′-diamine Dihydrochloride) 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 o-Tolidine Dihydrochloride 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: Sensitivity to Chlorine, Solubility, and Residue after Ignition.
[-C6H3(CH3)-4-NH2]2 • 2HCl
Formula Wt 285.21
CAS No. 612-82-8
GENERAL DESCRIPTION Typical appearance . . . . . . . . . . . . . . . . . . . off-white solid Applications . . . . . . . . . . . . . . . . . . . . . . . . indicator
SPECIFICATIONS Sensitivity to chlorine . . . . . . . . . . . . . . . . . Passes test Solubility. . . . . . . . . . . . . . . . . . . . . . . . . . Passes test Maximum Allowable Residue after ignition. . . . . . . . . . . . . . . . . . 0.1%
© 2017 American Chemical Society
A
DOI:10.1021/acsreagents.4408 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
TESTS Sensitivity to Chlorine Dissolve 0.7 g in 50 mL of water. Add this solution, with constant stirring, to 50 mL of dilute hydrochloric acid (3:7). Add 1 mL of this solution to 20 mL of water containing 5 mL of chlorine ion (Cl) standard solution. A distinct yellow color is produced that, when measured in a 1 cm cell against the chlorine standard at 430 nm, has an absorbance of not less than 0.42. (Absorbance readings should be made within 10 min.) (Limit 0.1 ppm free chlorine.)
Solubility Dissolve 0.50 g in 50 mL of water. The resulting solution should be complete and colorless.
Residue after Ignition Place 1.0 g in a tared, preconditioned porcelain crucible, add 0.5 mL of sulfuric acid, and slowly ignite in a hood. Heat in a furnace at 600 ± 25 °C to constant weight.
© 2017 American Chemical Society
B
DOI:10.1021/acsreagents.4408 ACS Reagent Chemicals, Part 4
