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AssigneeLovelace Biomedical & Environmental Research Institute, Inc.
InventorsMichael R. Strunk, William E. Bechtold
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A multidimensional gas chromatograph (GC) system having wide bore capillary and narrow bore capillary GC columns in series and having a novel system interface. Heart cuts from a high flow rate sample, separated by a wide bore GC column, are collected and directed to a narrow bore GC column with carrier gas injected at a lower flow compatible with a mass spectrometer. A bimodal six-way valve is connected with the wide bore GC column outlet and a bimodal four-way valve is connected with the narrow bore GC column inlet. A trapping and retaining circuit with a cold trap is connected with the six-way valve and a transfer circuit interconnects the two valves. The six-way valve is manipulated between first and second mode positions to collect analyte, and the four-way valve is manipulated between third and fourth mode positions to allow carrier gas to sweep analyte from a deactivated cold trap, through the transfer circuit, and then to the narrow bore GC capillary column for separation and subsequent analysis by a mass spectrometer. Rotary valves have substantially the same bore width as their associated columns to minimize flow irregularities and resulting sample peak deterioration. The rotary valves are heated separately from the GC columns to avoid temperature lag and resulting sample deterioration.
In a multidimensional gas chromatograph (GC) system for separating a multicomponent sample into its components and detecting said components, said system having a wide bore GC column, a narrow bore GC column, and an interface for directing at least a portion of an eluant from said wide bore GC column to said narrow bore GC column, the improvement wherein said system having eluant switching means operatively connected with an outlet of said wide bore GC column, final analyte switching means operatively connected with an inlet of said narrow bore GC column, and eluant trapping and retaining means located between and operatively connecting said eluant switching means and said final analyte switching means, said eluant trapping and retaining means being so configured as to be capable of flow isolation from each of said wide bore and said narrow bore GC columns by said eluant and said final analyte switching means whereby said eluant switching means is operable to direct selected portions of the eluant from said wide bore GC column to said trapping and retaining means to form a final analyte and said final analyte switching means is operable to direct said final analyte to said narrow bore GC column.
A method of operating a multidimensional GC system having a wide bore GC column, a narrow bore GC column, a mass spectrometer, and an interface for transferring selected portions of an eluate from said wide bore GC column to said narrow bore GC column, said interface having a bimodal six-way eluate switching valve and an analyte trapping and retaining circuit operatively connected therewith, a bimodal four-way final analyte switching valve operatively connected with said narrow bore GC column and a second injector, and a transfer circuit operatively connected with said eluate six-way switching valve and said final analyte four-way switching valve comprising the steps of:
A multidimensional gas chromatograph system comprising:
Dependencies are inferred from the claim text.