The CITEpro module “Condensed sample preparation (sediment, biota)” is used for the extraction, concentration and clean-up of mixtures of chemicals from environmental samples with a focus on sediment and biota. The methods cover samples from polluted sites as well as background locations.
The first step includes homogenization of the samples or thorough mixing. The chemicals are then extracted from the sample using (i) solvents, (ii) sampling cartridges or (iii) partitioning-based passive sampling into a polymer such as silicone. For passive sampling, automated mixing using rollers, shakers or stirrers is used to facilitate equilibration between the sample and the polymer. For (ii) and (iii), the chemicals are then extracted from the sampling phase using solvents and concentrated in the automated concentration unit. In some cases, the extracts are submitted to cleanup steps, e.g. using gel permeation chromatography, before being submitted to either (a) chemical analysis (modules #9 and #10) or (b) bioanalytical characterization (modules #1 to #4).
For chemical analysis, internal standard compounds are added using automatic eVol pipettes as part of the quality assurance/quality control scheme.
Transfer of mixtures of pollutants from the environment into a solvent extract (a) to be analyzed chemically or (b) to determine mixture effects.