The Best Way to Sample Volatile Organics for GC-MS?
Sometimes you need to capture everything.
So what is the right way of doing this?
There are many different ways of sampling volatile organic compounds in complex sample matrices such as foods, beverages and the like.
Headspace methods are strongly favoured since they leave troublesome matrix components behind and keep the GC-MS clean and trouble-free.
The challenge comes when you analyse identical samples with different headspace sampling techniques (static headspace, dynamic headspace, SPME, or headspace SBSE), and you get completely different patterns of peaks. So which gives the right answer?
The facile response (which contains a strong element of truth), is that it depends upon the question you are asking in the first place.
Each sampling technique favours the recovery of different parts of a sample’s volatile organic profile, and so the most appropriate choice will depend upon what compounds you are focusing on, and which technique gives you the best recovery for your target analytes.
However, there are plenty of occasions where you need an overall picture of a sample’s volatiles composition and, until now, a “universal” headspace technique hasn’t existed.
The applications teams working in GERSTEL’s laboratories in Germany and Japan have recently published a very significant paper in the Journal of Chromatography that details the performance of a new technique called the Multi-Volatile Method (MVM).
This new method enables the determination of volatiles in a wide range of matrices, where there is a need to analyse for many compounds covering a wide range of volatilities and matrix solubilities, and to do this in a single GC-MS run with good recoveries across the board.
This is an important and significant piece of work.
You can download a copy of this paper here: N. Ochiai , J. Tsunokawa, K. Sasamoto, A. Hoffmann; Journal of Chromatography A, 1371 (2014) 65-73
We plan to duplicate this work in the Anatune lab shortly, so if this is of interest to you please let us know, and we’ll see what we can do for you.