【国外标准】 Standard Test Methods for Determination of Dimer in Acrylic Acid (Withdrawn 2011)

These test methods provide a measurement of the dimer content of acrylic acid. The results of this measurement can be used for specification purposes but must be on an as-shipped basis since the dimer content will vary with the age and the storage temperature of the acrylic acid.1.1 Test Method A—Describes a chemical (titrametric) procedure for the determination of acrylic acid dimer in acrylic acid. This procedure may be applicable to other unsaturated organic acids.1.2 Test Method B—Describes a gas chromatographic procedure for the determination of acrylic acid dimer in acrylic acid. Other impurities may also be determined simultaneously.1.3 The following applies to all specified limits in this standard; for purposes of determining conformance with this standard, an observed value or a calculated value shall be rounded off "to the nearest unit" in the last right-hand digit used in expressing the specification limit, in accordance with the rounding-off method of Practice E 29.1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.5 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 Section 8.