Choosing the Right QuEChERS Extraction Salt
If you decide to try QuEChERS, you’re going to find that the extraction salt comes in three basic varieties which are the original QuEChERS method, the CEN method and the AOAC method.
The original method is sometimes referred to as the unbuffered method. What does that mean? Being unbuffered means the final sample pH is going to be determined just by the commodity itself. It’ll be what it’ll be.
In contrast, the CEN and AOAC methods are both buffered methods, which means they have salts that are intended for specific stable range. Most pesticides are at the level that’s a little below 5 pH for the AOAC method, or around 5-5.5 pH for the CEN method.
So which one should we pick? If you have pesticides that are rock solid and will be stable regardless of the final sample pH, the original method would work great for you. But if you have concerns about the stability of your sample due to the pH of the actual sample, then either of the buffered methods will be right for your application.
Good luck with your next QuEChERS extraction!