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Final Report: Report of the CCQM Pilot P26.1: Determination of Sulfur in Diesel Fuel



William R. Kelly, Robert D. Vocke Jr., Jacqueline L. Mann, Gregory C. Turk


The European Union and the United States have set new lower limits on sulfur in diesel transport fuel of 10 g/g and 15 g/g, respectively. Implementation of these regulations will require the production of high accuracy standards at these and lower levels by National Metrology Institute (NMI s). A CCQM-Pilot Comparison was organized by the Inorganic Analysis Working Group (IAWG) of CCQM to test the capabilities of NMIs to measure the sulfur content in diesel fuel at the 8 g/g (P26.1) level. In addition, a pilot study was performed concurrently on a Key Comparison (KC) sample at the 40 g/g level for laboratories preferring to participate in a pilot study rather than in the KC. Four NMI=s participated in both the Key Comparison and the Pilot Comparison: the Federal Institute for Materials Research and Testing (BAM), Institute for Reference Materials and Measurements (IRMM), Laboratory of the Government Chemist (LGC), and the National Institute of Standards and Technology (NIST). Three other laboratories agreed to participate, but only on the condition that they be permitted to analyze both materials as a Pilot Study. They were the National Center of Metrology of Mexico (CENAM), NIST, methodology. The agreement among these laboratories was good for the K35 sample as evidence by 1) the small values for both the degree of equivalence statements, Di, which is the absolute difference between a laboratory and the Key Comparison Reference Value (KCRV), and 2) their small associated uncertainties (U i). The four values determined by isotope dilution yielded Di values less than 0.8 g/g and u i values of 2.2 in one case and 1.4 in three cases. The same four participants had even better agreement for the designated P26.1 Pilot Study sample. The degree of equivalence statements, Di and U i were both less than 1 g/g. The three laboratories that used non-isotope dilution methods also exhibited good agreement with the reference values. At 8 g/g and 40 g/g sulfur levels the degree of equivalence, Di was less 1 g/g in 5 out of 6 cases.


diesel fuel, isotope dilution, key comparison, sulfur


Kelly, W. , Vocke, R. , Mann, J. and Turk, G. (2007), Final Report: Report of the CCQM Pilot P26.1: Determination of Sulfur in Diesel Fuel, Metrologia, [online], (Accessed April 13, 2024)
Created January 1, 2007, Updated March 15, 2017