Packaging and storage—
Preserve in tight containers, remote from heat, sparks, and open flames.
Identification—
The IR absorption spectrum of a thin film of it between potassium bromide plates or zinc selenide cells exhibits a broad, strong band at 2.7 µm to 3.2 µm, a strong maximum at about 3.4 µm, a medium strong maximum at about 3.5 µm, a weak region of absorption between 6.6 µm and 7.6 µm, and a very strong maximum at about 9.7 µm.
Acidity—
Mix 25 mL of water with 10 mL of alcohol and 0.5 mL of
phenolphthalein TS, and add 0.02 N sodium hydroxide until a slight pink color persists after shaking for 30 seconds. Taking precautions to avoid absorption of carbon dioxide, add 19 mL (15 g) of Methyl Alcohol, mix, and titrate with 0.020 N sodium hydroxide: not more than 0.45 mL is required to produce a pink color.
Alkalinity (as ammonia)—
Mix 28.6 mL (22.6 g) of it with 25 mL of water, add 1 drop of
methyl red TS, and titrate with 0.020 N sulfuric acid: not more than 0.20 mL is required to produce a pink color (3 ppm).
Readily carbonizable substances 
271
—
Cool 5 mL of
sulfuric acid TS, contained in a small conical flask, to 10
, and add 5 mL of Methyl Alcohol dropwise with constant mixing, maintaining the temperature below 20
throughout the test: no discoloration develops.
Nonvolatile residue—
Evaporate 250 mL of it in a 600-mL beaker on a steam bath, in a well-ventilated hood, until the volume is reduced to about 100 mL. Cool, transfer a portion of the liquid to a suitable, tared 50-mL platinum dish on a steam bath, evaporate, repeat the process until all of the liquid has been transferred, and evaporate to dryness. Dry at 105
for 30 minutes, cool, and weigh: the weight of the residue does not exceed 2 mg, corresponding to not more than 0.001% (w/w).
Acetone and aldehydes (as acetone)—
Standard preparation—
Dilute 1.9 mL (1.5 g) of acetone with water to 1000 mL, then dilute 1.0 mL of this solution with water to 100 mL, and mix. Dilute 2 mL of the resulting solution with water to 5 mL, and mix. The
Standard preparation contains 30 µg of acetone, and is freshly prepared.
Test preparation—
Dilute 1.25 mL (1 g) of it with water to 5 mL, and mix.
Procedure—
Adjust and maintain each solution at 20
. Add 5 mL of alkaline mercuric-potassium iodide TS to the
Standard preparation and to the
Test preparation, and mix: any turbidity produced in the
Test preparation is not greater than that produced in the
Standard preparation (0.003%).
Readily oxidizable substances—
Cool 20 mL of it to 15
, add 0.1 mL of 0.1 N potassium permanganate, and allow to stand at 15
: the pink color does not completely disappear within 5 minutes.
Assay—
Under typical conditions, the instrument is equipped with a flame-ionization detector and a 3-mm × 2-m stainless steel column packed with 50- to 80-mesh S4. The temperatures of the column, the injection port, and the detector are maintained at 140
, 220
, and 250
, respectively; and dry nitrogen is used as the carrier gas, at a flow rate of 20 mL per minute. Inject about 1 µL of Methyl Alcohol, and determine the peak responses by a convenient means. The retention time of methyl alcohol is about 2.5 minutes and that of acetone is about 7 minutes. Calculate the percentage of CH
4O in the Methyl Alcohol by dividing the response due to the methyl alcohol by the sum of the responses for all the peaks, and multiplying by 100.
;)
