ASTM D5453 for total sulfur in light hydrocarbons, motor fuels and motor oils
ASTM D5453 Standard Test Method for Determination of Total Sulfur in Light Hydrocarbons, Motor Fuels and Motor Oils by Ultraviolet Fluorescence
13. Report
13.1 For results equal to or greater than 10 mg/kg, report the sulfur result to the nearest mg/kg. For results less than 10 mg/kg, report the sulfur result to the nearest tenth of a mg/kg. State that the results were obtained according to Test Method D5453.
14. Quality Control
14.1 Confirm the performance of the instrument or the test procedure by analyzing a quality control (QC) sample (6.10) after each calibration and at least each day of use thereafter (see 10.5).
14.1.1 When QC/Quality Assurance (QA) protocols are already established in the testing facility, these can be used when they confirm the reliability of the test result.
14.1.2 When there is no QC/QA protocol established in the testing facility, Appendix X1 can be used as the QC/QA system.
15. Precision and Bias
15.1 The test method was examined in five separate interlaboratory studies. The precision of the test method, as obtained by statistical analysis of test results, is as follows (Note 11).
NOTE 11 - Volatile materials can cause a deterioration in precision when not handled with care (see Section 8 and 10.4).
15.1.1 Repeatability - The difference between two test results obtained by the same operator with the same apparatus under constant operating conditions on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the following values in only 1 case in 20, where x = the average of the two test results.
Less than 400 mg/kg: r = 0.1788X(0.75)
Greater than 400 mg/kg: r = 0.02902X
15.1.1.1 Research Report RR:D02-1547 (2000-2001) results:
Gasoline: r = 0.04356 (X + 14.844)
Diesel: r = 0.02777 (X + 28.158)
15.1.2 Reproducibility - The difference between two single and independent results obtained by different operators working in different laboratories on identical test material would, in the long run, in the normal and correct operation of the test method, exceed the following values in only 1 case in 20, where x = the average of the two test results.
Less than 400 mg/kg: R = 0.5797X(0.75)
Greater than 400 mg/kg: R = 0.1267X
15.1.2.1 Research Report RR:D02-1547 (2000-2001) results:
Gasoline: R = 0.3170 (X + 6.8847)
Diesel: R = 0.3659 (X + 2.1101)
15.2 Bias - The bias of this test method was determined in a 1992 research report, by analysis of standard reference materials (SRMs) containing known levels of sulfur in hydrocarbon. This report indicated that the results obtained on the SRMs were within the repeatability of the test method.
15.2.1 Three National Institute of Standards and Technology (NIST) Standard Reference Materials (SRM) were analyzed to determine the bias. These samples were gasoline SRMs 2298 (4.6 µg/g S) and 2299 (13.6 µg/g S), and diesel SRM 2723a (10 µg/g S). There was no significant bias for the diesel SRM, but there was a bias of -0.97 and -2.00 for gasoline SRMs 2298 and 2299, respectively.
15.3 Examples of the above precision estimates for samples containing less than 400 mg/kg are shown in Table 3.
16. Keywords
16.1 analysis; diesel; fluorescence; gasoline; jet fuel; kerosine; M-85; RFG; sulfur; ultraviolet
