ASTM D5769 Standard Test Method for Determination of Benzene, Toluene, and Total Aromatics in Finished Gasolines by Gas Chromatography/Mass Spectrometry
14. Precision and Bias
14.1 Precision - The precision of this test method as determined by a statistical examination of interlaboratory results is as follows:
14.1.1 Repeatability - The difference between successive results obtained by the same operator with the same apparatus under constant operating conditions on identical test materials would, in the long run, in the normal and correct operation of the test method, exceed the following values only in one case in twenty:
where X is the volume percent of the component.
14.1.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical test materials would, in the long run, in the normal and correct operation of the test method, exceed the following values only in one case in twenty:
where X is the volume percent of the component.
Table 8 summarizes the repeatability and reproducibility as a function of concentration volume %.
14.2 Bias - Since there is no certified reference material suitable for determining the bias for the procedures in this test method, bias cannot be determined.
15. Keywords
15.1 aromatics; benzene; gas chromatography; gasolines; GC/MS; mass spectrometry; toluene