Development of a new phase for lab-on-a-chip extraction of polycyclic aromatic hydrocarbons from water
Résumé
This work reports on the improved performance using nanoporous organosilicate (SiOCH) for lab-on a-chip extraction of organic pollutants from natural waters. Validations were carried out for polycyclic aromatic hydrocarbons (PAHs) extraction, and the results were compared with the commonly used SBSE laboratory technique (Stir-Bar Sorptive Extraction). While a previous study performed with PDMS coated lab-on-a-chips had showed limitations for the most polar PAHs (log K-ow < 5.5) and real matrices, we demonstrate here that, thanks to the novel phase, there is a good affinity for PAHs, even in natural waters. An improved microfluidic device in term of channel width and chip total area could be selected. Most importantly, the extraction time of 20 min still used with this type of microfluidic device is very short compared to the 24 h needed with the SBSE laboratory technique. Moreover, the high specific surface area of the nanoporous phase reduces the matrix effects related to interferences with dissolved organic matter. Therefore these new porous SiOCH coated extraction microchips appear as a good alternative to PDMS-based extraction techniques such as SBSE and should be used for further development of field analysis devices.