Method for predicting chemical or physical properties of complex mixtures

Claim 1

A method for predicting physical, perceptual, performance or chemical properties of a complex hydrocarbon mixture which comprises: (a) selecting at least one property of the hydrocarbon mixture; (b) selecting reference samples, said reference samples containing characteristic compound types present in the complex hydrocarbon mixture and which have known values of the property or properties selected in step (a); (c) producing a training set by the steps of: (1) injecting each reference sample into a gas chromatograph which is interfaced to a mass spectrometer thereby causing at least a partial separation of the hydrocarbon mixture into constituent chemical components; (2) introducing the constituent chemical components of each reference sample into the mass spectrometer, under dynamic flow conditions; (3) obtaining for each reference sample a series of time resolved mass chromatograms; (4) calibrating the mass chromatograms to correct retention times; (5) selecting a series of corrected retention time windows; (6) selecting within each retention time window a series of molecular and/or fragment ions, said ions being representative of characteristic compounds or molecular classes expected within the retention time window; (7) recording the total amount of each characteristic compound or compound group selected in step c(6); (8) forming the data from steps c(6) and c(7) into a X-block matrix; (9) forming the data selected in (a) for reference samples selected in (b) into a Y-block matrix; (10) analyzing the data from steps c(8) and c(9) by multivariate correlation techniques including Partial Least Squares, Principal Component Regression, or Ridge Regression to produce a series of coefficients; (d) subjecting an unknown hydrocarbon mixture to steps c(1) to c(3) in the same manner as the reference sample to produce a series of time resolved mass chromatograms; (e) repeating steps c(4) to c(8) for each mass chromatogram from step (d); (f) multiplying the matrix from step (e) by the coefficients from step c(10) to produce a predicted value of the property or properties.

Claim 2

A method for predicting physical, perceptual, performance or chemical properties of a complex hydrocarbon mixture which comprises: (a) selecting at least one property of the hydrocarbon mixture; (b) selecting reference samples, said reference samples containing characteristic compound types present in the complex hydrocarbon mixture and which have known values of the property or properties selected in step (a); (c) producing a training set by the steps of: (1) injecting each reference sample into a gas chromatograph which is interfaced to a mass spectrometer thereby causing at least a partial separation of the hydrocarbon mixture into constituent chemical components; (2) introducing the constituent chemical components of each reference sample into the mass spectrometer, under dynamic flow conditions; (3) obtaining for each reference sample a series of time resolved mass chromatograms; (4) calibrating the mass chromatograms to correct retention times; (5) selecting a series of corrected retention time windows; (6) selecting within each retention time window a series of molecular and/or fragment ions, said ions being representative of characteristic compounds or molecular classes expected within the retention time window; (7) recording the total amount of each characteristic compound or compound group selected in step c(6); (8) forming the data from steps c(6) and c(7) into a X-block matrix; (9) forming the data selected in (a) for reference samples selected in (b) into a Y-block matrix; (10) analyzing the data from steps c(8) and c(9) by multivariate correlation techniques including Partial Least Squares, Principal Component Regression, or Ridge Regression to produce a series of coefficients; (d) subjecting an unknown hydrocarbon mixture to steps c(1) to c(3) in the same manner as the reference sample to produce a series of time resolved mass chromatograms; (e) repeating steps c(4) to c(8) for each mass chromatogram from step (d); (f) multiplying the matrix from step (e) by the coefficients from step c(10) to produce a predicted value of the property or properties.