Significance and Use
Accurate gas chromatographic determination of trace levels of thiophene in benzene involves special analytical problems because of the difficulties of trace level analysis. These problems arise from the low concentration levels that need to be measured, the type of column and detector needed for analysis, and the potential interference from the benzene matrix.
This test method was found applicable for determining thiophene in refined benzene conforming to the specifications described in Specifications D2359, D4734, and D5871 and may be applicable toward other grades of benzene if the user has taken the necessary precautions as described in the text.
This test method was developed as an alternative technique to Test Methods D1685 and D4735.
1.1 This test method covers the determination of thiophene in refined benzene using gas chromatography and sulfur selective detection. The test method is applicable to the determination of thiophene at levels of 0.02 to 2.18 mg thiophene per kg in benzene (mg/kg) on the AED, 0.03 to 1.87 mg/kg on the PFPD, and 0.03 to 2.11 mg/kg on the SCD. The range of the test method may be extended by modifying the sample injection volume, split ratios, calibration range, or sample dilution with thiophene-free solvent.
1.2 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.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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 and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 7.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D1193 Specification for Reagent Water
D1685 Test Method for Traces of Thiophene in Benzene by Spectrophotometry
D2359 Specification for Refined Benzene-535
D3437 Practice for Sampling and Handling Liquid Cyclic Products
D4734 Specification for Refined Benzene-545
D4735 Test Method for Determination of Trace Thiophene in Refined Benzene by Gas Chromatography
D5871 Specification for Benzene for Cyclohexane Feedstock
D6809 Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E1510 Practice for Installing Fused Silica Open Tubular Capillary Columns in Gas Chromatographs
atomic emission detector; benzene; chemiluminescence detector; gas chromatography; pulsed flame photometric detector; sulfur; thiophene; Gas chromatography (GC); Refined benzene; Sulfur selective detection; Thiophene content;
ICS Number Code 75.160.20 (Liquid fuels)
ASTM International is a member of CrossRef.
Citing ASTM Standards
[Back to Top]