【国外标准】 Standard Guide for Purity of Monomeric Plasticizers by Gas Chromatography

5.1 Infrared techniques frequently cannot detect low-level materials. Gas chromatographic methods possess higher sensitivity and are used to extend limits of detection.5.2 It is expected that this guide will be suitable for specifications, manufacturing control, and research and development. An area percent method of determining concentration of the components shall be used if the area percent of the plasticizer is 99.0 % or higher. However, if the area percent of the plasticizer is less than 99.0 % or if any question were to arise about the data, an internal standard shall be used.5.3 Impurities potentially found in monomeric plasticizers include alcohols, dibasic acids, and monoesters.1.1 This gas chromatographic guide covers a procedure for extending the range of purity determination of monomeric plasticizers beyond that now determined by other methods. Due to the need to volatilize the plasticizer, only monomeric plasticizers having definitive boiling points and a molecular weight less than 1000 Daltons, such as dioctyl phthalate, are applicable to this guide.1.2 The values in SI units are to be regarded as standard.1.3 The text of this guide references notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) are not to be considered as requirements of this guide.1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 9.NOTE 1: There is no known ISO equivalent to this standard.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.