کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1207650 | 965276 | 2011 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: A flexible loop-type flow modulator for comprehensive two-dimensional gas chromatography A flexible loop-type flow modulator for comprehensive two-dimensional gas chromatography](/preview/png/1207650.png)
The present investigation is focused on a simple flow modulator (FM), for comprehensive two-dimensional gas chromatography (GC × GC). The interface is stable at high temperatures, and consists of a metallic disc (located inside the GC oven) with seven ports, which are connected to an auxiliary pressure source via two branches, to the first and second dimension, to a waste branch (linked to a needle valve) and to an exchangeable modulation loop (2 ports). The ports are connected via micro-channels, etched on one of the inner surfaces of the disc. Modulation is achieved using a two-way electrovalve, connected on one side to the additional pressure source, and to the two metal branches, on the other. An FM enantio-GC × polar-GC method (using a flame ionization detector) was optimized (a 40-μL loop was employed), for the analysis of essential oils. As an example, an application on spearmint oil is shown; the method herein proposed was subjected to validation. Finally, an FM GC × GC diesel experiment was carried out, using an apolar–polar column combination, to demonstrate the effectiveness of the modulator in the analysis of a totally different sample-type.
Journal: Journal of Chromatography A - Volume 1218, Issue 21, 27 May 2011, Pages 3140–3145