Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Isopentyl Alcohol (Isoamyl Alcohol; 3-Methyl-1-butanol) 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 Isopentyl Alcohol 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, Water, Titrable Acid, Residue after Evaporation, Acids, Esters, and Carbonyl Compounds.
(CH3)2CHCH2CH2OH
Formula Wt 88.15
CAS No. 123-51-3
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . . Density . . . . . . . . . . . . . . . .
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clear liquid organic solvent boiling point, 131 °C 2 g in 100 mL at 14 °C 0.81
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥98.5% C5H11OH Maximum Allowable Water (H2O) . . . . . . . . . . . . . . . . . . . . . . . . 0.5% Titrable acid . . . . . . . . . . . . . . . . . . . . . . . 0.002 meq/g Residue after evaporation . . . . . . . . . . . . . . . 0.003%
© 2017 American Chemical Society
A
DOI:10.1021/acsreagents.4180 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Acids and esters (as amyl acetate) . . . . . . . . . 0.2% Carbonyl compounds (as HCHO) . . . . . . . . . . . 0.1%
TESTS Assay 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 isopentyl alcohol content in area percent. Correct for water content.
Water [Part 2: Titrimetric Methods; Water by the Karl Fischer Method; Volumetric Procedure; Volumetric Procedure for Samples Using Karl Fischer Reagent, Method 1]. Use 25 mL (20 g) of the sample.
Titrable Acid To 20 g (25 mL) of sample in a glass-stoppered flask, add 0.15 mL of phenolphthalein indicator solution and shake for 1 min. No pink color should form. Titrate the solution with 0.01 N methanolic potassium hydroxide volumetric solution to a faint pink color that persists for at least 15 s. Not more than 4.0 mL of the methanolic potassium hydroxide should be consumed.
Residue after Evaporation [Part 2: Gravimetric Methods; Residue after Evaporation]. Evaporate 40 g (50 mL) to dryness in a tared, preconditioned dish on a steam bath, and dry the residue at 105 °C for 30 min.
Acids and Esters Dilute 100 mL of sample with 100 mL of anhydrous isopropyl alcohol, add 25.0 mL of 0.1 N methanolic potassium hydroxide volumetric solution, and heat gently under a reflux condenser for 10–15 min. Cool, and add 20 mL of carbon dioxide-free water through the reflux condenser. Detach the flask, add 0.15 mL of phenolphthalein indicator solution, and titrate the excess potassium hydroxide with 0.1 N hydrochloric acid to a colorless end point. The volume of 0.1 N potassium hydroxide consumed in the test should not be more than 12.3 mL greater than the volume consumed in a complete blank test.
Carbonyl Compounds Test solution preparation: Add 203 µL formaldehyde solution (37%), 150 µL acetaldehyde, 194 µL propionaldehyde, 199 µL acetone, 237 µL butyraldehyde, and 240 µL 2-butanone to 90 mL of the sample, and add more sample to make 100.0 mL. (Molar equivalents to 1000 µg/g formaldehyde added). Analyze the sample and the test solution by GC–MS according to the procedure in [Part 2: Chromatography; Gas Chromatography–Mass Spectrometry]. For the column in [Part 2: Chromatography; Gas Chromatography–Mass Spectrometry], set inlet temperature and pressure to 120 °C and 154 kPa. Inject 1 µL of sample with a 5:1 split ratio. Oven temperature profile: isothermal at 40 °C for 20 min, 5 °C/min to 90 °C, hold 1 min, 40 °C/min to 220 °C, hold 5.75 min. The area of each of the carbonyl peaks in the sample should be no greater than half that of the corresponding peak in the test solution.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4180 ACS Reagent Chemicals, Part 4
