ASTM D1839 Standard Test Method for Amyl Nitrate in Diesel Fuels
3. Summary of Test Method
3.1 This test method is based on the simultaneous hydrolysis of the ester in 62.5 % sulfuric acid and nitration of m-xylenol by the nitric acid liberated. The nitroxylenol is distilled from the reaction mixture and reacted with sodium hydroxide to form the yellow sodium salt. Residual diesel fuel is removed by ether extraction. The color is measured spectrophotometrically at 452 nm, and the concentration of amyl nitrate is determined by reference to a standard curve.
4. Significance and Use
4.1 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.
5. Interferences
5.1 Nitrate esters, inorganic nitrate ions, and nitrogen oxides will interfere to give high results.
