Partial Modulation Method via Pulsed Flow Modulator for Comprehensive Two-Dimensional Gas Chromatography

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• 作者：Huamin Cai and Stanley D. Stearns
• 刊名：Analytical Chemistry
• 出版年：2004
• 出版时间：October 15, 2004
• 年：2004
• 卷：76
• 期：20
• 页码：6064 - 6076
• 全文大小：346K
• 年卷期：v.76,no.20(October 15, 2004)
• ISSN：1520-6882

文摘

A partial modulation method by using a pulsed-flowmodulator for comprehensive two-dimensional gas chromatography is proposed. The method is based on the factthat when a pulsed flow of inert gas is introduced into theconjunction between a primary and a secondary column,the concentration of analyte is disturbed, and a plug ofhigher or lower concentration is created. The plug, whichforms a spike signal coupled to the primary GC signal, isthen separated in a secondary column, creating a newdimension of GC information. The modulation is partialbecause only a fraction of the primary signal is modulatedand converted into the secondary signal; the remainingprimary signal stays unchanged. Therefore, this methodyields a comprehensive two-dimensional chromatogramand a primary one-dimensional chromatogram in a singleGC run. In this study, the modulation mode, modulationindex, and modulation percentage are discussed and thereproducibility of peak areas and retention time areinvestigated. With a 5.8% modulation percentage and aprimary peak half-width 1.7 times wider than the modulation time, the standard deviation for the peak areas are0.15% for the primary and 0.78% for the secondarychromatograms. Chromatograms of laboratory-mixed hydrocarbons and of high-temperature fuel oil no. 6 standard are demonstrated.