(koe loe' dee on).
» Collodion contains not less than 5.0 percent, by weight, of pyroxylin.
Add the Alcohol and the Ether to the Pyroxylin contained in a suitable container, and insert the stopper into the container well. Shake the mixture occasionally until the Pyroxylin is dissolved.
[CautionCollodion is highly flammable. ]
Packaging and storage Preserve in tight containers, at a temperature not exceeding 30, remote from fire.
Labeling The label bears a caution statement to the effect that Collodion is highly flammable.
A: When exposed to air in a thin layer, it leaves a transparent, tenacious film. The film of pyroxylin so obtained burns rapidly, with a yellow flame.
B: When mixed with an equal volume of water, it yields a viscid, stringy mass of pyroxylin.
Specific gravity 841: between 0.765 and 0.775.
Acidity Add 5 mL of it to 5 mL of water: the liquid separated from the pyroxylin is not acid to litmus.
Alcohol content 611
Internal standard solution Place 20 mL of acetone in a glass-stoppered, 100-mL graduated cylinder, dilute with 1,2-dichloroethane to 100 mL, and mix.
Standard solutions Pipet 10-, 20-, and 30-mL portions of dehydrated alcohol into separate 100-mL volumetric flasks, dilute with 1,2-dichloroethane to volume, and mix.
Standard preparations Pipet 10 mL of each Standard solution into separate glass-stoppered, 50-mL graduated cylinders. To each add 15 mL of 1,2-dichloroethane, 10 mL of hexane, and 10.0 mL of Internal standard solution, and mix.
Test preparation Pipet 10 mL of Collodion into a glass-stoppered, 50-mL graduated cylinder containing 15 mL of 1,2-dichloroethane, 10 mL of hexane, and 10.0 mL of Internal standard solution, mix, and allow the precipitate to settle.
Chromatographic system Under typical conditions, the instrument is equipped with a thermal conductivity detector, and it contains a 1.8-m × 3.5-mm glass column containing packing S3; the injection port, the detector, and the column temperatures are maintained at 200, 250, and 150, respectively; and helium is used as the carrier gas, at a flow rate of about 50 mL per minute.
Procedure Inject a suitable volume (about 4 µL) of each Standard preparation and of the Test preparation into a suitable gas chromatograph, and record the chromatograms (so as to obtain about 25% of maximum recorder response for the least concentrated solution). Calculate the relative response factor, F, for each Standard solution taken by the formula:
F = CS / RSin which CS is the concentration of C2H5OH in the Standard solution, in percentage (V/V); and RS is the area-ratio of alcohol to acetone observed for the respective Standard preparation. Calculate the percentage of alcohol, CU, in the test specimen taken by the formula:
CU = FaRUin which Fa is the average of the individual F values; and RU is the area-ratio of alcohol to acetone observed for the Test preparation. The content of C2H5OH is between 22.0% and 26.0%.
Assay Pour quickly about 10 mL of Collodion into a tared flask, insert the stopper, weigh the assay charge accurately, remove the stopper, warm on a steam bath, and add 10 mL of water dropwise, with constant stirring. Evaporate the mixture on a steam bath, and dry the residue at 105 for 4 hours. The weight of the pyroxylin so obtained corresponds to not less than 5.0%, by weight, of the assay charge.