ASTM D4423 Standard Test Method for Determination of Carbonyls in C4 Hydrocarbons
7. Preparation of Apparatus
7.1 Dry Ice-Stoddard Solvent Bath - Add a sufficient quantity of Stoddard solvent into the Dewar flask to ensure that the cooling coil will be submerged in the liquid plus dry ice (solid CO2). (Warning - See 6.6 and 6.7.) Carefully add sufficient dry ice to the Stoddard solvent to obtain a temperature of at least -50 °C. (Warning - Great care must be taken during this step. Do not add the dry ice all at once, but in small pieces, especially at the beginning. Wear protective gloves and adequate eye protection to prevent any contact with the extremely cold materials.) Attach the sample cylinder containing the butadiene (Warning - Extremely flammable gas under pressure. May form explosive peroxides upon exposure to air. Harmful if inhaled. Irritating to eyes, skin, and mucous membranes.) to the cooling coil and immerse the coil into the liquid. Support the sample cylinder in a cylinder rack or using a ring stand and appropriate clamps. Be sure the coil is positioned so that the delivery tip is free to dispense liquid butadiene into the Erlenmeyer flasks. After each use, be sure to clean the coil's interior with methanol. DO NOT USE ACETONE.
