Analysis of chemically samples using gas chromatography (GC) separation with vacuum ultra-violet spectroscopy detection is described. One technique focuses on assigning a specific analysis methodology to each constituent in a sample. Constituents can elute from the GC by themselves or with other constituents, in which case a deconvolution is done using VUV spectroscopic data. In an exemplary embodiment, each constituent may be specifically included in an analysis method during a setup procedure, after which the same series of analyses are done on subsequent sample runs. The second approach essentially integrates an entire chromatogram by first reducing it into a series of analysis windows, or time slices, that are analyzed automatically. The analysis at each time slice determines the molecular constituents that are present as well as their contributions to the total response. Either approach can be used to quantify specific analytes or to do bulk classification.