My Trip to Japan to Learn Selectable 1D/2D-GC/MS
Written by Paul Roberts, Anatune’s Application Laboratory Manager.
I recently visited GERSTEL KK in Tokyo to learn about a new chromatographic technique – Selectable 1D/2D-GC/MS.
I started my trip early Saturday morning to fly to Tokyo, a flight of thirteen hours. I arrived very early Sunday morning feeling a little worse for wear. After resting for the remainder of the weekend, I was fully fired up to start my training on Monday morning.
The GERSTEL Selectable 1D/2D-GC/MS is a flexible system, based on a single standard GC/MS instrument. It is both a routine GC-MS and also a complex problem solving system, that offers heart-cutting and two-dimensional separation on demand.
Because of this dual functionality, when questions arise regarding a poorly resolved section of the standard one-dimensional chromatogram, the section in question can be transferred to a 2nd dimension GC column, with different polarity to greatly improve the separation. Both columns are installed in the same GC and are heated independently using Low Thermal Mass (LTM II) technology.
The process of cutting a section of a chromatogram and introducing it to another column is called heart-cutting. The 1D/2D system can be used to determine analytes in either the 1st or the 2nd dimension in a flexible manner, without having to reconfigure the hardware at all. Neither the GC run, nor analyte detection is interrupted when this happens. Detection of the analytes transferred to the 2nd column uses the same detector(s) used for the 1st dimension: MSD and Olfactory Detection Port (ODP), in this case.
During my time in Tokyo we covered many aspects of the 1D/2D system including; installation and functionality of the LTM II modules which are core components of the system. Core functionality including Dean’s switch and splitter was also covered.
We looked at building a system from the ground up including the use of xDCalc software to calculate system pressures and the required lengths of connection and restriction capillaries to ensure optimum linear velocities through the two LTM columns in the system. We also covered all aspects of software operation which is achieved via GERSTEL Maestro and MSD Chemstation.
An important part of the system is the Aroma Office 2D software. This is a database application that uses Retention Indices (RI) to search the data acquired with 1D or 2D GC/MS.
The Aroma Office database contains many hundreds of entries for flavour and fragrance compounds from published literature. With Aroma Office, a cross search can be performed by using two different RIs acquired from both 1st and 2nd dimensional chromatograms. This combined with the selectable 1D/2D-GC/MS system provides an easy to use and highly accurate search result for flavour and fragrance compounds. Valuable, when many significant compounds give poor identifications using MS.
After going through the theory, building the system from scratch and discussion on applications, it was time to put the system through its paces.
We successfully applied the 1D/2D-GC/MS system to the analysis of coffee powder using automated solvent extraction and large volume injection, followed by 1D/2D-GC-O/MS. We successfully heart-cut key flavour compounds from the complex coffee matrix and acheived excellent resolution on the second column.
The next we tackled was to analyse a selection of whiskies using fully evaporative dynamic headspace (FET DHS) followed by 1D/2D-GC-O/MS, again following this analysis we managed to heart-cut and identify trace aroma compounds from the samples.
All in all, a very rewarding trip. I learnt a tremendous amount regarding the Selectable 1D/2D-GC/MS system which I am putting to good use immediately.
I made great friends with the guys at GERSTEL KK and sampled some amazing food.
I had never been to Japan before this visit, but I will definitely be returning.