Sample Derivatisation – the (Very Strong) Case for Automation

Martin Perkins

22nd January 2012

We were discussing sample derivatisation this week and Andrew Golby summed up his experience (and that of many other analysts) as follows:

There are three things I do know about derivatisation; it uses nasty chemicals, it’s a pain in the butt and it never works properly!

Gas Chromatography is a simple, useful, inexpensive analytical tool, but it is applicability is limited to analytes of moderate polarity that are volatile and thermally stable. Its usefulness can be extended by reacting analytes with derivatisation agents to form less polar derivatives that are more stable and more volatile and that can be analysed by GC.

This is fine, but there is a penalty to pay in terms of the work needed at the bench to prepare the samples prior to analysis and as AG pointed out; the reagents are usually toxic and difficult to handle. If you have more than a few samples to run, the work is soul destroying and, unless you are careful to treat every sample exactly the same, the results can be all over the place.

Modern laboratory robots (like the GERSTEL MultiPurpose Sampler), make light work of sample derivatisation and addresses all three shortcomings that Andrew highlights:

You and your staff gain from greatly reduced exposure to nasty stuff, robots are much better than people at doing exactly the same thing time after time after time and, unlike people, robots don’t get bored with routine tasks.