Automating Sample Preparation – Thinking Differently
“When you have a hammer in your hand, everything looks like a nail”
Just about everyone using GC-MS or LC-MS find themselves working with solid or semi-solid samples at some point, and for many analysts it is something they do on a routine basis.
For the first time, there promises to be a way of fully automating these extractions.
The chances are that, in general terms, the sample preparation process you use looks something like this:
- Weigh out some samples
- Add solvent and internal standard
- Shake hard
- Add salts and/or buffers for phase-separation and pH-adjustment
- Shake hard again
- Take an aliquot of the organic phase
- Perform and solid phase clean-up
- Remove water
- Centrifuge to obtain a particulate free extract
- Inject into GC-MS and/or LC-MS
Your sample prep may employ every step listed here or may be a simplified version of the above, but if you have a way of automating as many of these steps as you need, you would have the means to save a great deal of time and effort and your data quality would be greatly improved.
For the first time this is becomming possible.
World-wide, huge numbers of food samples are analysed every day to test for things that shouldn’t be there – pesticide residues, veterinary residues and the like. Technically, the sample preparation is very challenging, since food isn’t a single matrix (it can include juice, fruit & veg and dried cereals for example, and have widely varying proportions of solids, sugars, proteins, water and lipids). What’s more, the target analytes will be different in virtually every case.
Despite this, in 2002-3, a group of leading food analysts came up with two generic approaches to this challenge that have proved to be very effective and are now very widely adopted. This way of doing things has proved itself to be:
Quick, Easy, Cheap, Effective, Rugged and Safe
Together, these approaches are known by the name of QuEChERS.
Up to now, the principle drawback has been that this is a wholly manual process. However, the launch of the Teledyne Tekmar Automate-Q40 has changed things. The Automate-Q40 is an automated sample preparation work-bench that:
- Automates all, or part of the whole work-flow listed above
- Has the flexibility to accommodate the adaptations needed to cope with a wide range of analyte/matrix combination that may be encountered
Now here are tha couple of important points that I want to make.
Firstly, QuEChERS sample preparation, is by its nature a general purpose sample preparation process. It can be applied to other matrix/analyte combinations.
Secondly, if you were under pressure to cut costs, improve data quality, improve your labs efficiency and perhaps secure your organisations’ position in a competitive market. Which of these two approaches would you favour?
- Stick with your existing manual method and maybe tweak it a bit, or;
- Try a more radical approach, and see if the Automate can be adapted to automate the whole process.
I think I would look at option 2 first. What do you think?
If you want to know more about QuEChERS in general, you can visit the QuEChERS website.