Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Aniline (Benzenamine) 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 Aniline provides, in addition to common physical constants, a general description including typical appearance, applications, change in state (approximate), aqueous solubility, density, and pKa. The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Assay, Chlorobenzene, Color (APHA), Residue after Ignition, Hydrocarbons, and Nitrobenzene.
C6H5NH2
Formula Wt 93.13
CAS No. 62-53-3
Note: This reagent darkens to a reddish-brown color on storage.
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . . Density . . . . . . . . . . . . . . . . pKa . . . . . . . . . . . . . . . . . .
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oily liquid solvent boiling point, 184 °C 3.6 g in 100 mL at 20 °C 1.02 4.6
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥99.0% C6H5NH2
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4038 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Color (APHA) . . . . . . . Residue after ignition. . Chlorobenzene (C6H5Cl) Hydrocarbons . . . . . . . Nitrobenzene (C6H5NO2)
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Maximum Allowable 250 0.005% 0.01% Passes test Passes test
TESTS Assay and Chlorobenzene Analyze the sample by gas chromatography using the general parameters cited in [Part 2: Chromatography; Recommended Procedures; Gas Chromatography]. The following specific conditions are also required. Column . . . . . . . . . . . . . . . . . . . . . . . . . . Type I, methyl silicone Measure the area under all peaks and calculate the area percent for aniline and chlorobenzene.
Color (APHA) [Part 2: Measurement of Physical Properties; Color (APHA); Procedure for Color (APHA)].
Residue after Ignition [Part 2: Gravimetric Methods; Residue after Ignition]. In a preconditioned, tared crucible, evaporate 20 g (20 mL) to dryness in the hood, and ignite.
Hydrocarbons Mix 5 mL with 10 mL of hydrochloric acid. The solution should be clear after dilution with 15 mL of cold water.
Nitrobenzene
For the Determination of Nitrobenzene
S a m p l e S o l u t i o n A . Place 10 mL of methanol in a 25 mL glass-stoppered graduated cylinder. C o n t r o l S o l u t i o n B . Place 10 mL of methanol in a 25 mL glass-stoppered graduated cylinder, and add 1 mL of a methanol solution containing 0.10 mg of nitrobenzene per mL.
Immerse the cylinders in a beaker of water at or below room temperature, and add 10 mL of the aniline and 2.5 mL of hydrochloric acid to each. Mix well, and bring to room temperature. Transfer a portion of sample solution A to a polarographic cell, and deaerate with nitrogen or hydrogen. Record the polarogram from –0.2 to –0.7 V vs SCE with a current sensitivity of 0.02 µA/mm. Repeat this procedure with control solution B. The diffusion current in sample solution A should not exceed the difference in diffusion current between control solution B and sample solution A. (Limit about 0.001%.)
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4038 ACS Reagent Chemicals, Part 4
