ASTM D7621 Standard Test Method for Determination of Hydrogen Sulfide in Fuel Oils by Rapid Liquid Phase Extraction
13. Report
13.1 The test report shall contain at least the following information:
13.1.1 A reference to this standard and the procedure (A or B) followed,
13.1.2 All details necessary for complete identification of the product tested,
13.1.3 The result of the test (see Section 12),
13.1.4 Any deviations, by agreement or otherwise, from the procedures specified, and
13.1.5 The time and date of the test.
14. Precision and Bias
14.1 General:
14.1.1 Procedure A (Distillate and Residual Fuels) - The precision values given in 14.2 and 14.3 were derived from a 2012 Energy Institute ILS which used eight instruments and eight operators, at a single location, to test 12 samples in duplicate and in random order. The precision of the sample types covered the H2S levels of 0.60 mg/kg to 12.5 mg/kg.
14.1.2 Procedure B (Distillate Fuels) - The precision values for distillate fuels given in 14.2 and 14.3 were derived from a 2011 Energy Institute ILS which used 10 instruments and 10 operators, at a single location, to test 8 samples in duplicate and in random order. The precision of the sample types covered the H2S levels of 0.40 mg/kg to 9.70 mg/kg.
14.1.3 Procedure B (Residual Fuels) - The precision values for residual fuels and blend stocks given in 14.2 and 14.3 were derived from a 2009 Energy Institute ILS that used 7 instruments and seven operators, at a single location, to test 15 samples in duplicate and in random order. The precision of the sample types covered the H2S levels of 0.40 mg/kg to 15.3 mg/kg and viscosities up to 3000 mm2s(-1) at 50 ºC.
14.1.4 The minimum ranges for precision were derived from the pooled limit of quantitation.
NOTE 9 - As the precision was determined from results obtained at a single location the reproducibility may not be comparable when results obtained at different times and locations are compared, due to sampling, shipping, storage and environmental factors. In practice two results obtained from different locations would be acceptable if their difference did not exceed the published reproducibility.
14.1.5 The precision was obtained by statistical examination of the laboratory study test results according to ISO 4259 (Practice D6300) using ADJ6300 D2PP.
14.2 Repeatability - The difference between successive test results obtained by the same operator with the same apparatus under constant operating conditions on nominally identical test material would, in the normal and correct operation of the test method, exceed the value shown in Table 2 in only in one case in 20.
14.2.1 See Table X2.1 for tabular illustration.
14.3 Reproducibility - The difference between two test results independently obtained by different operators using different apparatus on nominally identical test material would, in the normal and correct operation of the test method, exceed the value shown in Table 3 in only in one case in 20.
14.3.1 See Table X2.2 for tabular illustration.
14.4 Bias - Since there is no accepted reference material suitable for determining bias, for the procedures in this method, for measuring hydrogen sulfide, bias has not been determined. Limited information on the degree of agreement with IP 399 for Procedure B residual fuels is available in the research report.
15. Keywords
15.1 blend stocks; bunkers; crude oil; H2S; hydrogen sulfide; liquid phase; marine; residual fuel oil
