ASTM D 2622-05 «Standard test method for sulfur in petroleum products by wave length dispersive X-ray fluorescence spectrometry».
This test method covers the determination of total sulfur in petroleum and petroleum products that are single-phase and either liquid at ambient conditions, liquefiable with moderate heat, or soluble in hydrocarbon solvents. These materials can include diesel fuel, jet fuel, kerosene, other distillate oil, naphtha, residual oil, lubricating base oil, hydraulic oil, crude oil, unleaded gasoline.
Sulfur determination in petroleum and petroleum products ASTM D 2622-05
No sample preparation for analysis is required.
The sample in a sample cup is exposed to primary X-ray tube emission in spectrometer. Countrate of S-Kα emission is measured. Sulfur content is determined with calibration curve for the given concentration range.
Compared with the other test methods of sulfur determination this one has high precision, minimal sample preparation, high speed of analysis in a wide sulfur concentration range.
The sample in a sample cup is exposed to primary X-ray tube emission in spectrometer. Countrate of S-Kα emission is measured. Sulfur content is determined with calibration curve for the given concentration range.
Compared with the other test methods of sulfur determination this one has high precision, minimal sample preparation, high speed of analysis in a wide sulfur concentration range.
The test method describes sulfur determination in the range from 0,0003% up to 5,3% (m/m).
The precision of the test method was determined by statistical analysis of results obtained in three separate interlaboratory studies.
The first interlaboratory study (Case I) covered distillates, kerosines, residual oils, and crude oils.
The second interlaboratory study (Case II) covered a set of 21 gasolines. Neither M-85 nor M-100 was included.
The third interlaboratory study (Case III) involved 16 samples each of low level sulfur gasoline and diesel sample types analyzed by 28 laboratories.
Sulfur concentration range of the test samples and precision are given in tables 1 and 2.
Repeatability
The difference between successive test results obtained by the same operator with the same apparatus under constant operation conditions on identical test material would, in the long run, in normal and correct operation of the test method exceed the following values only on case in twenty.
Table 1
Where Х – sulfur concentration, mass % .
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 normal and correct operation of the test method exceed the following values in one case in twenty.
Table 2
where X is sulfur concentration, mass %.
The precision of the test method was determined by statistical analysis of results obtained in three separate interlaboratory studies.
The first interlaboratory study (Case I) covered distillates, kerosines, residual oils, and crude oils.
The second interlaboratory study (Case II) covered a set of 21 gasolines. Neither M-85 nor M-100 was included.
The third interlaboratory study (Case III) involved 16 samples each of low level sulfur gasoline and diesel sample types analyzed by 28 laboratories.
Sulfur concentration range of the test samples and precision are given in tables 1 and 2.
Repeatability
The difference between successive test results obtained by the same operator with the same apparatus under constant operation conditions on identical test material would, in the long run, in normal and correct operation of the test method exceed the following values only on case in twenty.
Table 1
| Case | Concentration range, mass % | Repeatability |
| I | 0,006 - 5,3 | 0,02651 Х0,9 |
| II | 0,0003 - 0,093 | 0,00736(Х + 0,0002)0,4 |
| III | 0,0024 - 0,0080 | 0,02438(Х + 0,012469) |
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 normal and correct operation of the test method exceed the following values in one case in twenty.
Table 2
| Case | Concentration range, mass % | Reproducibility |
| I | 0,006 - 5,3 | 0,0913 Х0,9 |
| II | 0,0003 - 0,093 | 0,0105(X + 0,0002)0,4 |
| III | 0,0024 - 0,0080 | 0,04795(Х + 0,012469) |