【国外标准】 Standard Test Method for Determining Chloride in Aromatic Hydrocarbons and Related Chemicals by Microcoulometry

5.1 Organic as well as inorganic chlorine compounds can prove harmful to equipment and reactions in processes involving hydrocarbons.5.2 Maximum chloride levels are often specified for process streams and for hydrocarbon products.5.3 Organic chloride species are potentially damaging to refinery processes. Hydrochloric acid can be produced in hydrotreating or reforming reactors and this acid accumulates in condensing regions of the refinery.1.1 This test method covers the determination of organic chloride in aromatic hydrocarbons, their derivatives, and related chemicals.1.2 This test method is applicable to samples with chloride concentrations to 25 mg/kg. The limit of detection (LOD) is 0.2 mg/kg and the limit of quantitation (LOQ) is 0.7 mg/kg. With careful analytical technique or the measurement of replicates, or both, this method can be used to successfully analyze concentrations below the LOD.NOTE 1: The maximum is the highest concentration from the interlaboratory study and the LOD and LOQ were calculated from Performance Testing Program (PTP) data. See Table 1.1.3 This test method is preferred over Test Method D5194 for products, such as styrene, that are polymerized by the sodium biphenyl reagent.1.4 In determining the conformance of the test results using this method to applicable specifications, results shall be rounded off in accordance with the rounding-off method of Practice E29.1.5 Organic chloride values of samples containing inorganic chlorides will be biased high due to partial recovery of inorganic species during combustion. Interference from inorganic species can be reduced by water washing the sample before analysis. This does not apply to water soluble samples.1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.7 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. For specific hazard statements, see 7.3 and Section 9.1.8 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.