ASTM D6069 Test Method for Trace Nitrogen in Aromatic Hydrocarbons
ASTM D6069 Standard Test Method for Trace Nitrogen in Aromatic Hydrocarbons by Oxidative Combustion and Reduced Pressure Chemiluminescence Detection
15. Precision and Bias
15.1 Precision - The following criteria, conducted under the guidelines of Practice E 691, should be used to judge the acceptability (95 % probability) of the results obtained by this test method. The criteria were derived from a interlaboratory study between ten laboratories. Standards and samples were analyzed in duplicate on the same day by a single operator. Each analysis represented triplicate injections.
15.1.1 Repeatability - Results within laboratory results by the same operator with the same equipment over the shortest practicable period of time should not be considered suspect unless they differ by more than the amount shown in Table 1.
15.1.2 Reproducibility - Results submitted by two laboratories should not be considered suspect unless they differ by more than the amount shown in Table 1.
15.2 Bias - Systematic error that contributes to a difference between the mean and an accepted reference value. Since all organic solvents can contain nitrogen, an absolute statement of bias could not be determined from this study. Although, an estimate of bias was determined by spiking a single solvent (xylene) with three different concentrations of nitrogen. These three spiked samples were then analyzed as unknowns in the interlaboratory study (see Table 2).
16. Keywords
16.1 chemiluminescence; nitrogen
