There is no designated method or equivalent methods for sulfur. We now have a performance based system where labs have to meet precision and accuracy criteria for whatever method they choose to use. A number of methods should be able to be used to meet the precision and accuracy criteria, but this will be done on a lab-specific basis.
Question and Answer was originally posted at Questions and Answers on the Clean Diesel Fuel Rules (PDF)(135 pp, 888 K, EPA420-B-06-010, July 2006, About PDF)