【国外标准】 Standard Test Method for Purity of Hydrocarbons from Freezing Points (Withdrawn 2019)

4.1 The experimental procedures and physical constants provided by this test method, when used in conjunction with Test Method D1015, allow the determination of the purity of the material under test. A knowledge of the purity of these hydrocarbons is often needed to help control their manufacture and to determine their suitability for use as reagent chemicals or for conversion to other chemical intermediates or finished products.1.1 This test method covers the sampling and determination of purity of essentially pure compounds for which the freezing points for zero impurity and cryoscopic constants are given.2 The compounds to which the test method is applicable are: (Warning—Extremely flammable liquids and liquefied gases.)n-butane 1,3-butadieneisobutane isoprene(2-methyl-1,3-butadiene)n-pentane benzeneisopentane toluene (methylbenzene)n-hexane ethylbenzenen-heptane o-xylene (1,2-dimethylbenzene)n-octane m-xylene (1,3-dimethylbenzene)2,2,4-trimethylpentane p-xylene (1,4-dimethylbenzene)methylcyclohexane styrene (ethenylbenzene)isobutene  1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Sections 1, 6, 8, and 10 – 26.NOTE 1: This test method covers systems in which the impurities form with the major component a substantially ideal or sufficiently dilute solution, and also systems which deviate from the ideal laws, provided that, in the latter case, the lowering of the freezing point as a function of the concentration is known for each most probable impurity in the given substance.