13.2: Advances in GC
- Page ID
- 220491
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)
\( \newcommand{\dsum}{\displaystyle\sum\limits} \)
\( \newcommand{\dint}{\displaystyle\int\limits} \)
\( \newcommand{\dlim}{\displaystyle\lim\limits} \)
\( \newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\)
( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\)
\( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)
\( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\)
\( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)
\( \newcommand{\Span}{\mathrm{span}}\)
\( \newcommand{\id}{\mathrm{id}}\)
\( \newcommand{\Span}{\mathrm{span}}\)
\( \newcommand{\kernel}{\mathrm{null}\,}\)
\( \newcommand{\range}{\mathrm{range}\,}\)
\( \newcommand{\RealPart}{\mathrm{Re}}\)
\( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)
\( \newcommand{\Argument}{\mathrm{Arg}}\)
\( \newcommand{\norm}[1]{\| #1 \|}\)
\( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)
\( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\AA}{\unicode[.8,0]{x212B}}\)
\( \newcommand{\vectorA}[1]{\vec{#1}} % arrow\)
\( \newcommand{\vectorAt}[1]{\vec{\text{#1}}} % arrow\)
\( \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\( \newcommand{\vectorC}[1]{\textbf{#1}} \)
\( \newcommand{\vectorD}[1]{\overrightarrow{#1}} \)
\( \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} \)
\( \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} \)
\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)
\(\newcommand{\longvect}{\overrightarrow}\)
\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)
\(\newcommand{\ket}[1]{\left| #1 \right>}\)
\(\newcommand{\bra}[1]{\left< #1 \right|}\)
\(\newcommand{\braket}[2]{\left< #1 \vphantom{#2} \right| \left. #2 \vphantom{#1} \right>}\)
\(\newcommand{\braopket}[3]{\left< #1 \vphantom{#2}\vphantom{#3} \right| #2 \vphantom{#1}\vphantom{#3} \left| #3 \vphantom{#1}\vphantom{#2} \right>}\)
\(\newcommand{\qmvec}[1]{\mathbf{\vec{#1}}}\)
\(\newcommand{\op}[1]{\hat{\mathbf{#1}}}\)
\(\newcommand{\expect}[1]{\langle #1 \rangle}\)
\(\newcommand{\dfn}[1]{\emph{\textbf{#1}}}\)
Multidimensional Gas Chromatography (GC-GC, 2D-GC)
Recently the idea of multidimensional gas chromatography separations has be proven to be very useful for closely eluting solutes in experiments with a single column. (see Liu and Phillips, Journal of Chromatographic Science. 29 (6), 227–231, 1991). Multidimensional GC is based upon sending groups of closely eluting solutes (on a long column of one selectivity onto a second shorter column of a different selectivity). As shown in Figure\(\PageIndex{1}\) a fast value is used to the red and blue co-eluting in Column 1 solutes onto Column 2 where are being further separated they are better separated.
Figure\(\PageIndex{1}\) : A schematic diagram of a two dimension GC instrument. Image source currently unknow.
An example of the utility of multidimensional GC is shown in Figure\(\PageIndex{2}\) - Figure\(\PageIndex{4}\). Figure\(\PageIndex{2}\) depicts a typical one dimensional GC separation of a large number of polycyclic aromatic compounds on an appropriate coluum. Despite the 40 m length of the capillary column, there are numerous examples of co-eluting solutes presented in the focus boxes.
Figure\(\PageIndex{2}\) : The gas chromatograph for a large series of polycyclic aromoatic solutes on a 40 M RXi-PAH column. Imge source currently unknown
Figure\(\PageIndex{3}\) reveals the 2D chromatogram when the solutes eluting through the RXi-PAH column arriving between approximately 15 and 24 min in Figure\(\PageIndex{1}\) are directed onto a short, 1 M, RXi-1HT column for separation on a column with a different selectivity. (Note an even longer RXi-PAH column, 60 M, was used in the the 2D GC instrument)
Figure\(\PageIndex{3}\): A focused region in the 2D - GC experiment of the solutes eluting from approximately 15 min to 24 min in Figure 12.2.2. Image source currently unknown.
Figure\(\PageIndex{4}\) is a zoom of the region in Figure 12.2.3 corresponding to the box centered at 16 min in Figure\(\PageIndex{2}\) and containing the signals for benz[a]anthracene, chrysene, triphenylene and cyclopenta[cd]pyrene revealing the full resolution for the separation of these solutes.
ht
Figure\(\PageIndex{4}\) : A focused region in the 2D - GC experiment revealing the full resolution of the following solutes: benz[a]anthracene, chrysene, triphenylene and cyclopenta[cd]pyrene. Image source currently unknown.