scope:

This method is for determining basic organic nitrogen in petroleum distillates using potentiometric titration. This method may be applied to both clear and colored samples. The range of quantitation for petroleum distillates is from 0.0005 to 1.0 mass-% nitrogen, while for viscous materials, such as heavy oils, the range is 0.001 to 5.00 mass-% nitrogen. This method may give erroneous results for materials containing bases other than nitrogen compounds (e.g., caustic-washed distillates containing sodium soaps, or crude oil containing inorganic bases).

Clear or very lightly colored samples may be analyzed down to a lower limit of quantitation of 0.5 mass-ppm (0.00005 mass-%) using the color indicator titration technique described in the Appendix.