Today one often finds hydrocarbon mixtures described by the detailed carbon type analysis that is possible from 13C NMR.
Many petroleum related products are being described in this way in patents leading to a novel way of describing a material and restricting others from using those same materials in products of their own. See Exxon, Mobil, and Chevron patents such as:
6,090,989 ; 6,210,559 ; 6,059,955 ; 6,846,778 ; 20050077208 ; and 20050077209
In this PDF file we have shown some of the details present in a 13C NMR spectrum on petroleum products such a base oils, gas oils, diesels, etc.
There are some issues with the assignements of many of these patents … for more details on how NMR might be of use in the patent process contact John Edwards