1. A system for analyzing complex samples, the system comprising: a gas chromatograph including an injector and a column, wherein the injector is configured to insert a sample along with a flowing gas into the column; a flame ionization detector (FID); a mass spectrometer; a divider configured to divide constituents of the sample that are exiting the column for contemporaneous delivery to the flame ionization detector and the mass spectrometer; and a data processor for acquiring and processing data obtained from the flame ionization detector and the mass spectrometer, wherein the data processor is configured to process the data by combining detection information from the flame ionization detector and the mass spectrometer, wherein the data processor further provides detailed composition information for the sample and the sample comprises hydrocarbon, wherein the detailed composition information comprises a quantitative percent mass yield as a function of a boiling point of the hydrocarbon components of the sample.