Experimental Study of the Quantitative Precision for Valve-Based Comprehensive Two-Dimensional Gas Chromatography

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• 作者：W. Christopher Siegler ; Brian D. Fitz ; Jamin C. Hoggard ; Robert E. Synovec
• 刊名：Analytical Chemistry
• 出版年：2011
• 出版时间：July 1, 2011
• 年：2011
• 卷：83
• 期：13
• 页码：5190-5196
• 全文大小：888K
• 年卷期：v.83,no.13(July 1, 2011)
• ISSN：1520-6882

文摘

For complex sample analysis, there is a need for multidimensional chromatographic instrumentation to be able to separate more compounds, often in shorter time frames. This has led to the development of comprehensive two-dimensional chromatographic instrumentation, such as comprehensive two-dimensional gas chromatography (GC 脳 GC). Lately, much of the focus in this field has been on decreasing peak widths and, therefore, increasing peak capacity and peak capacity production. All of these advancements make it possible to analyze more compounds in a shorter amount of time, but the data still need to remain quantitative to address the needs of most applications. In this report, the relationship among the modulation ratio (M_R), peak sampling phase (), retention time variation (螖t_R), and how these parameters relate to quantitative analysis precision via the relative standard deviation (RSD) was studied experimentally using a valve-based GC 脳 GC instrument. A wide range of the number of modulations across the first dimension peak width, that is, a M_R range from 1 to 10, was examined through maintaining an average first dimension peak width at the base, ¹w_b of 3 s and varying the second dimension separation run time from 300 to 2900 ms. An average RSD of 2.1% was experimentally observed at an average M_R of 2, with a corresponding peak capacity production of 1200 peaks/min possible. Below this M_R the RSD quickly increased. In a long-term study of the quantitative precision at a M_R of 2.5, using 126 replicate injections of a test mixture spanning 35 h, the RSD averaged 3.0%. The findings have significant implications for optimizing peak capacity production by allowing the use of the longest second dimension run time, while maintaining quantitative precision.