Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Diethanolamine (2,2′-Iminodiethanol) 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 Diethanolamine provides, in addition to common physical constants, a general description including typical appearance, applications, change in state (approximate), aqueous solubility, and density. The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Assay, 2-Aminoethanol, Triethanolamine, Apparent Equivalent Weight, Color (APHA), Residue after Ignition, and Water.
(HOCH2CH2)2NH
Formula Wt 105.14
CAS No. 111-42-2
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . . Density . . . . . . . . . . . . . . . .
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clear, viscous liquid buffer formulation boiling point, 268–269 °C miscible 1.09
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥98.5% (HOCH2CH2)2NH Apparent equivalent weight. . . . . . . . . . . . . . 104.0–106.0 Maximum Allowable Color (APHA) . . . . . . . . . . . . . . . . . . . . . . . 15 Residue after ignition. . . . . . . . . . . . . . . . . . 0.005% 2-Aminoethanol . . . . . . . . . . . . . . . . . . . . . 1.0% Triethanolamine . . . . . . . . . . . . . . . . . . . . . 1.0% Water (H2O) . . . . . . . . . . . . . . . . . . . . . . . . 0.15%
© 2017 American Chemical Society
A
DOI:10.1021/acsreagents.4118 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
TESTS Assay, 2-Aminoethanol, and Triethanolamine 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 Make a 10% (w/w) mixture of the sample with ethyl alcohol. Measure the area under all peaks, and calculate the diethanolamine, 2-aminoethanol, and triethanolamine content in area percent. Correct for water content and ethyl alcohol.
Apparent Equivalent Weight To 50 mL of water in a 250 mL conical flask, add 0.3 mL of mixed indicator solution (described below), and neutralize by adding 0.1 N hydrochloric acid just to disappearance of the green color. From a suitable weighing pipette, introduce 1.8–2.0 g of sample, weighing to within 0.5 mg. Mix and titrate with standard 0.5 N hydrochloric acid to disappearance of the green color.
For the Determination of Apparent Equivalent Weight
M i x e d I n d i c a t o r S o l u t i o n . Prepare separate solutions of bromocresol green and methyl red in methanol (0.1 g/100 mL). When needed, mix freshly each day 5 parts of the bromocresol green solution with 1 part of the methyl red solution.
Color (APHA) [Part 2: Measurement of Physical Properties; Color (APHA); Procedure for Color (APHA)].
Residue after Ignition [Part 2: Gravimetric Methods; Residue after Ignition]. Evaporate 50.0 g (45 mL) to dryness in a tared, preconditioned dish. Add 0.10 mL of sulfuric acid, again evaporate to dryness, and finally ignite at 600 ± 25 °C.
Water [Part 2: Titrimetric Methods; Water by the Karl Fischer Method; Coulometric Procedure; Coulometric Procedure for Samples Using Karl Fischer Reagent, Method 2]. Use 0.1 g of the sample.
© 2017 American Chemical Society
B
DOI:10.1021/acsreagents.4118 ACS Reagent Chemicals, Part 4
