BUTYLENE ANALYSIS BY GC: ASTM D4424
EXPLANATION
This test method can be used to determine butylenes stream composition for custody transfer payments. It can also provide data necessary to evaluate processing requirements in an operating plant. The method covers the gas chromatographic analysis of commercial butylenes, butylenes concentrates, and butane-butylene mixtures. It does not cover high purity butene-1 or high purity isobutene streams, or both. However, it is possible that one or more columns listed in the method may be capable of the separation necessary for high-purity analyses.
This test method covers the following components at about 0.05 % or greater: propane, propylene, isobutene, n-butene, isobutene, trans-butene-2, cis-butene-2, 1,3-butadiene, iso-pentane, and n-pentane. It is not intended for trace hydrocarbon analysis.
TEST SUMMARY
The sample is separated in a gas chromatograph system using a packed chromatographic column with either helium or hydrogen as the carrier gas. The separated components of the sample are detected either by a thermal conductivity detector or by a flame ionization detector. Calibration data are obtained by using either relative response factors or by using a standard calibration blend.
TEST PRECISION
The test method precision has not yet been developed. Bias cannot be determined since no accepted standard reference material is available for this method.
