ASTM D4423 Standard Test Method for Determination of Carbonyls in C4 Hydrocarbons
5. Apparatus
5.1 Bunsen Valves - A device constructed so that when used with an Erlenmeyer flask, the sample vapors can exit the flask while protecting the flask's liquid contents. See Fig. 1 for details.
5.2 Cooling Coil - Prepare a cooling coil by winding about 10 cm to 15 cm of seamless copper tubing (about 6 mm diameter) on a short length of pipe (about 1.5 cm to 2.0 cm diameter), allowing sufficient length of tubing at the end of the coil to connect it to the sample source. Attach a valve at a point that would not extend more than 8 cm above the surface of the cooling bath liquid. To the valve, attach a 6 cm to 8 cm length piece of tubing bent downward so that the hydrocarbon liquid can be directed into the receiving container.
5.3 Dewar Flask - The Dewar flask must be of sufficient volume to completely immerse the main portion of the cooling coil except for the extremities necessary for receiving and delivering the sample through the coil.
5.4 Erlenmeyer Flasks, 250 mL capacity.
5.5 Volumetric Flasks, 1 L capacity. These flasks should be Class A glassware.
5.6 Graduated Cylinders - 100 mL capacity, glass cylinders, graduated in 1 mL or 2 mL divisions.
5.7 Microburets, 2.00 mL or 5.00 mL capacity. The microburets should be Class A glassware with 0.01 mL or 0.02 mL divisions or less. It is advisable to have the buret's tip end equipped with a syringe needle to dispense very small drops of titrant.
5.8 Sample Cylinders - These should be of sufficient volume to give the required amount of sample for testing. Stainless steel cylinders equipped with needle valves should be used. It is suggested that a 500 mL-capacity cylinder be the minimum size to be used for butadiene.
5.9 Thermometer - For observing temperatures below -45 °C. The Low Cloud and Pour Point Thermometer, conforming to the requirements for ASTM Thermometer 6C, as prescribed in Specification E1, is satisfactory. Thermometer 6C has a range from -80 °C to +20 °C. Temperature measuring devices that cover the temperature range of interest, such as the ASTM 1C thermometer, or liquid-in-glass thermometers, thermocouples, or platinum resistance thermometers that provide equivalent or better accuracy and precision may be used.
6. Reagents and Materials
6.1 Purity of Reagents - Reagent grade chemicals should be used in all tests. Unless otherwise indicated, it is intended that all reagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.
6.2 Purity of Water - Unless otherwise indicated, references to water shall be understood to mean Type II reagent water conforming to Specification D1193.
6.3 Alcoholic Hydrochloric Acid(0.05 N) - Dilute 4.2 mL of concentrated hydrochloric acid (Warning - Poison. Corrosive. May be fatal if swallowed. Liquid and vapor cause severe burns. Harmful if inhaled.) to volume with anhydrous methanol in a 1 L volumetric flask. Use the alcoholic 0.05 N potassium hydroxide solution to standardize the HCl solution.
6.4 Alcoholic Hydroxylamine Hydrochloride - Dissolve 35.0 g of hydroxylamine hydrochloride (Warning - May be irritating to skin, eyes, or mucous membranes. Harmful if inhaled.) in 3.5 L of anhydrous methanol. (Warning - Flammable. Vapor harmful. May be fatal or cause blindness if swallowed or inhaled. Cannot be made nonpoisonous.)
6.5 Alcoholic Potassium Hydroxide (0.05 N) - Dissolve 3.3 g of potassium hydroxide in anhydrous methanol. (Warning - Corrosive. Can cause severe burns or blindness. Evolution of heat produces a violent reaction or eruption upon too rapid mixture with water.) Make to volume with methanol in a 1 L volumetric flask. Standardize against a primary standard, potassium acid phthalate.
6.6 Dry Ice (Carbon Dioxide Solid) - (Warning - Extremely cold (-78.5 °C). Liberates heavy gas which may cause suffocation. Contact with skin causes burns or freezing, or both. Vapors may react violently with hot magnesium or aluminum alloys.)
6.7 Stoddard Solvent - Conforming to the specification listed in Specification D484. (Warning - Combustible. Vapor harmful.)
6.8 Thymol Blue Indicator - Dissolve 0.04 g of thymol blue in 100 mL of anhydrous methanol. (Warning - Flammable. Vapor harmful. May be fatal or cause blindness if swallowed or inhaled. Cannot be made nonpoisonous.)
