ASTM D5808 Organic Chloride in Aromatic Hydrocarbons and Related Chemicals
ASTM D5808 Standard Test Method for Determining Organic Chloride in Aromatic Hydrocarbons and Related Chemicals by Microcoulometry
1. Scope
1.1 This test method covers the organic chlorides in aromatic hydrocarbons, their derivatives, and related chemicals.
1.2 This test method is applicable to samples with chloride concentrations from 1 to 25 mg/kg.
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 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.
1.5 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 7.3 and Section 9.
2. Referenced Documents
2.1 ASTM Standards:
D1193 Specification for Reagent Water
D3437 Practice for Sampling and Handling Liquid Cyclic Products
D5194 Test Method for Trace Chloride in Liquid Aromatic Hydrocarbons
E 29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E 691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
2.2 Other Document:
OSHA Regulations - 29CFR paragraphs 1910.1000 and 1910.1200
3. Terminology
3.1 Definitions:
3.1.1 dehydration tube - chamber containing concentrated sulfuric acid that scrubs the effluent gases from combustion to remove water vapor.
3.1.2 oxidative pyrolysis - a process in which a sample is combusted in an oxygen-rich atmosphere at high temperature to break down the components of the sample into elemental oxides.
3.1.3 recovery factor - an indication of the efficiency of the measurement computed by dividing the measured value of a standard by its theoretical value.
3.1.4 reference sensor pair - detects changes in silver ion concentration.
3.1.5 test titration - a process that allows the coulometer to set the endpoint and gain values to be used for sample analysis.
3.1.6 titration parameters - various instrumental conditions that can be changed for different types of analysis.
3.1.7 working electrode (generator electrode) - an electrode consisting of an anode and a cathode separated by a salt bridge; maintains a constant silver ion concentration.
