The disclosed system and method improve measurement of trace volatile chemicals, such as by Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GCMS). A first trapping system can include a plurality of capillary columns in series and a focusing column fluidly coupled to a first detector. The first trapping system can retain and separate compounds in a sample, including C3 hydrocarbons and compounds heavier than C3 hydrocarbons (e.g., up to C12 hydrocarbons, or compounds having a boiling point around 250° C.), and can transfer the compounds from the focusing column to the first detector. A second trapping system can receive compounds that the first trapping system does not retain, and can include a packed trap, a polar column and a PLOT column fluidly coupled to one or more second detectors. The second trapping system can remove water from the sample and can separate and detect compounds including C2 hydrocarbons and Formaldehyde.

Provided herein are methods of liquid column chromatography in which preparative chromatography is performed in-line with analytical chromatography. In particular aspects a monolithic preparative column is used to purify an analyte of interest from a mixture of other substances by applying the mixture to the column, reversing the flow through the column to elute the analyte, which is applied to an analytical column provided in-line with the preparative column. In other aspects, a single monolithic column is used to perform both the preparative chromatography and analytical chromatography steps in succession. In another aspect, a chromatography system is provided to perform preparative and analytical chromatography using a single monolithic column.

The disclosed system and method improve measurement of trace volatile chemicals, such as by Gas Chromatography (GC) and Gas Chromatography/Mass Spectrometry (GCMS). A first trapping system can include a plurality of capillary columns in series and a focusing column fluidly coupled to a first detector. The first trapping system can retain and separate compounds in a sample, including C3 hydrocarbons and compounds heavier than C3 hydrocarbons (e.g., up to C12 hydrocarbons, or compounds having a boiling point around 250 C.), and can transfer the compounds from the focusing column to the first detector. A second trapping system can receive compounds that the first trapping system does not retain, and can include a packed trap, a polar column and a PLOT column fluidly coupled to one or more second detectors. The second trapping system can remove water from the sample and can separate and detect compounds including C2 hydrocarbons and Formaldehyde.