Patent ID: 7056744

Claim:
A method of determining the short-chain branching distribution in a hydrocarbon sample, comprising: a) obtaining vibrational spectra of at least two training samples having different, known degrees of short-chain branching; b) finding at least one parameter of the vibrational spectra that correlates with the known difference in the degree of short-chain branching between the at least two training samples; c) by chemometric analysis, defining a mathematical relationship between the value of the at least one parameter and the degree of short-chain branching in the training samples; d) providing a hydrocarbon test sample and isolating at least one fraction from the hydrocarbon test sample; e) determining the value of the at least one parameter for the at least one fraction; and f) applying the mathematical relationship to the parameter values for the at least one fraction, thereby determining the degree of short-chain branching in the at least one fraction.