A 3D centrifugal cartridge with gravity valve, capillary valves, and Coriolis switching valve was designed, fabricated, and tested for Solid Phase Extraction (SPE). In particular, the novel three-dimensional gravity valve helps to release reagents in not-sequentially increased rotation speeds. The sequential control of these valves was simply achieved by manipulating the rotating direction and speed of the cartridge. The prototype microfluidic cartridge was 3D printed with a FDM printer and experimentally tested. Anthracene, which was one of the Polycyclic Aromatic Hydrocarbons (PAHs), was used as the target analyte and tested. C18 was used as the stationary sorbent and fluorescence method was adopted to detect anthracene. The concentrations of the anthracene testing samples were 1μg/L (1ppb), 5μg/L, and 10μg/L (anthracene/water), respectively. The volumes of testing sample and eluent (nonane) were 10mL and 1mL respectively. Experiments showed that 7 times of enrichment of the original samples were achieved. This centrifugal SPE system could be potentially used as a portable on-situ pollutant enrichment and detection device.
|