Contaminant analysis in complex matrices

Extraction

The extraction of the contaminant is a key step in the analytical process. Indeed, the extraction of a contaminant from a complex matrix requires a selective extraction method to avoid the co-extraction of components from the sample that would interfere with the contaminant analysis. In addition, the presence of the contaminant at trace levels often requires a quantitative extraction in order to be able to then detect and quantify the contaminant in the extract. However, this is not always possible, especially when the contaminant is strongly bound to the matrix.

Most of the time, the extract will need to be concentrated (or even purified) to allow contaminant analysis.

Your Investigation

Which technique(s) do you suggest to extract and then purify ochratoxin A from coffee?

Clue

Several techniques are available for solid matrices: (i) a simple extraction by stirring with a solvent, (ii) Soxhlet extraction technique, (iii) pressurized hot extraction, (iv) supercritical fluid extraction. To purify the extract, a solid phase extraction can be performed.