Development of sampling and preconcentration devices
Sampling is the preliminary step in all analyses. When an instrument operates in real-time and continuously, this sampling phase must be automated. To achieve sufficient sensitivity for the detection of pollutants in the environment, a pre-concentration phase is often necessary and is an integral part of sampling.
There are two general cases. In the first case, the pre-concentration is not selective, and many molecules of interest are trapped. The following steps must then include a separation and detection capable of discriminating between each of the target molecules. In a second case, this sampling and preconcentration step is selective to one or more compounds, for example, from the same family. This makes it possible to use shorter separation steps or dispense with them, and potentially less efficient detectors.
Selective preconcentration is therefore of great interest and can be obtained with functionalised and/or hierarchical materials.