4.1 In diesel fuel, the presence of alkyl nitrates such as amyl nitrate, hexyl nitrate, or octyl nitrate causes a higher residue value than observed in untreated fuel, which can lead to erroneous conclusions as to the coke forming propensity of the fuel. The presence of such alkyl nitrate in the fuel can be determined using this test method. This test method can be used to determine the amount of amyl nitrate that has been added to diesel fuels to improve cetane number. This test method is applicable as a basis for judging compliance with specifications covering amyl nitrate.

1.1 This test method covers the determination of 0.1 to 0.5 volume % amyl nitrate in diesel fuels.

Note 1: This test method has been used for the determination of hexyl nitrate in diesel fuels, but has not been cooperatively tested for such samples. For the determination of hexyl nitrate, use standards containing nitrate esters of primary hexanol. Use a density of 0.97 in calculating results.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.