A procedure for quantitative 13c-n.m.r. application to the characterisation of the naphtha fraction of petroleum crude

A method for optimising the conditions for the quantitative ¹³C-n.m.r. measurement is suggested and has been applied to the compositional studies of naphtha fractions (50–100°C and 100–150°C) of Darius crude oil. The novelty of the method is that we can pre-estimate the pulse repetition time for unknown samples. It has been shown that the various compositional parameters thus obtained are in satisfactory agreement with those obtained from the elemental analysis, fluorescent indicator adsorption (FIA) and ¹H-n.m.r. spectrometry.