Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Dioxane (1,4-Dioxane) 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 Dioxane 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, Freezing Point, Color (APHA), Peroxide, Residue after Evaporation, Titrable Acid, Carbonyl Compounds, Water. Special caution is advised for the handling or testing of this substance.
C4H8O2
Formula Wt 88.11
CAS No. 123-91-1
C a u t i o n : Dioxane tends to form explosive peroxides, especially when anhydrous. It should not be allowed to evaporate to dryness unless the absence of peroxides has been shown.
Note: Dioxane usually contains a stabilizer. If a stabilizer is present, its identity and quantity must be stated on the label.
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . . Density . . . . . . . . . . . . . . . . pKa . . . . . . . . . . . . . . . . . .
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© 2017 American Chemical Society
clear liquid organic solvent boiling point, 100–102 °C miscible 1.03 –2.9
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DOI:10.1021/acsreagents.4125 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥99.0% C4H8O2 Freezing point . . . . . . . . . . . . . . . . . . . . . . Not below 11.0 °C Maximum Allowable Color (APHA) . . . . . . . . . . . . . . . . . . . . . . . 20 Peroxide (as H2O2). . . . . . . . . . . . . . . . . . . . 0.005% Residue after evaporation . . . . . . . . . . . . . . . 0.005% Titrable acid . . . . . . . . . . . . . . . . . . . . . . . 0.0016 meq/g Carbonyl (as HCHO) . . . . . . . . . . . . . . . . . . . 0.01% Water (H2O) . . . . . . . . . . . . . . . . . . . . . . . . 0.05%
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 dioxane content in area percent. Correct for water content.
Freezing Point A p p a r a t u s . For the sample container, use a test tube (25 mm × 100 mm) supported by a cork in a water-tight glass cylinder (50 mm × 110 mm). Mount the cylinder in a water bath that provides at least a 37 mm layer of water surrounding the sides and bottom of the cylinder. Center an accurate thermometer with 0.1 °C subdivisions in the test tube, and mount a thermometer with 1 °C subdivisions in the water bath. Use a wire about 30 cm long with a loop at the bottom as the stirrer. Pour sufficient sample into the test tube to make a 50 mm column. Assemble the apparatus with the bulb of the 0.1 °C thermometer immersed halfway between the top and bottom of the sample in the test tube. Fill the water bath with a mixture of ice and water to within 12 mm of the top, and adjust the temperature to 0 °C by the addition of more ice, if necessary. Stir the sample continuously during the test by moving the wire loop up and down throughout the entire depth of the sample at a regular rate of 20 cycles per min. Record the reading of the 0.1 °C thermometer every 30 s. Anticipate that the temperature will fall gradually at first, then become constant for 1–2 min at the freezing point, and finally fall gradually again. The freezing point is the average of 4 consecutive readings that lie within a range of 0.2 °C.
Color (APHA) [Part 2: Measurement of Physical Properties; Color (APHA); Procedure for Color (APHA)].
Peroxide Dilute 10 mL of the dioxane with water to 50 mL, and use 5.0 mL of the solution (1.0 g sample). For the standard, dilute a solution containing 0.05 mg of hydrogen peroxide standard with water to 5.0 mL. Add 5.0 mL of titanium tetrachloride reagent solution to each, and mix. After standing for 5 ± 1 min, any yellow color in the solution of the sample should not exceed that in the standard. The color intensities may be determined with a spectrophotometer in 1 cm cells at a wavelength of 410 nm.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4125 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
C a u t i o n : If peroxide is present, do not perform the test for residue after evaporation.
Residue after Evaporation [Part 2: Gravimetric Methods; Residue after Evaporation]. Evaporate 20.0 g (19.0 mL) to dryness in a tared, preconditioned platinum dish on a hot plate (~100 °C), and dry the residue at 105 °C for 30 min.
Titrable Acid Mix 31.0 g (30 mL) with 30 mL of carbon dioxide-free water, and titrate with 0.01 N sodium hydroxide, using phenolphthalein as the indicator. Not more than 5.0 mL of the titrant is required.
Carbonyl Compounds Test solution preparation: Add 26 µL formaldehyde solution (37%), 19 µL acetaldehyde, 25 µL acetone, 24.5 µL propionaldehyde, 30 µL butyraldehyde, and 30.2 µL 2-butanone to 100 mL of the 1,4-dioxane sample. (Molar equivalents to 100 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 6 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.
Water [Part 2: Titrimetric Methods; Water by the Karl Fischer Method; Coulometric Procedure; Coulometric Procedure for Samples Using Karl Fischer Reagent, Method 2]. Use 100 µL (103 mg) of the sample.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4125 ACS Reagent Chemicals, Part 4
