## 6 Important Applications
### Continuous Porous Polymers in Solid-Phase Extraction  
Polymers used as supports for solid phase extraction must have good hydrodynamic properties and an important specific surface. As mentioned above, the continuous porous polymers present these requirements, which convert them in potential carriers for the application in this field. [PERSON] _et al._[144] prepared Sty-derived polymer rods with specific surface as high as 400 m\({}^{2}\)/g, being permeable to liquid at reasonably low pressures. These polymers were used as supports in SPE of different phenols at high flow rates. These phenols were adsorbed 30 times more than conventional media.  
In a recent work reported by [PERSON] [145], monolithic columns were employed to collect and concentrate neuronal release from invertebrate and vertebrate model systems, prior to their characterization with mass spectrometry. The supports were prepared in fused-silica capillaries from lauryl methacrylate (LMA) and EgDMA. Their binding capacities (determined using fluorescein and fluorescently labeled peptides) were on the order of nanomoles per millimeter of length of monolith and their limit of detection (determined for angiotensin I and insulin in artificial seawater) was on the order of femtomole. Then, to evaluate their behavior for collecting and concentrating peptide release, the capillaries were positioned directly above, but not in contact with the surface of the bag cell cluster from the _A. californica_ abdominal ganglion, as well as cortical regions of a mouse coronal brain slice (see Figure 13). Upon electrical or chemical stimulation, the secreted chemicals were retained on the monolith, washed of excess salts, released from the porous polymer, and detected with MALDI-TOF MS. Comparing these results with those obtained using individual beads placed on brain slices, the monolithic capillaries showed greater binding capacity and maintained higher spatial resolution, compared to the larger-volume, solid-phase extraction collection strategies.  
In another interesting approach to the development of microfluidic chips to be used as supports in SPE, [PERSON] _et al._[146] prepared an array of eight porous monolithic columns into a polymeric chip to be tested for SPE cleanup of biological samples prior to directly coupled electrospray mass spectrometry (ESI-MS). The polymers were synthesized using BMA and EgDMA as monomers. The polymerization mixture was vacuumed simultaneously into the eight parallel channels (10 mm long, 360 _i_m i.d.) using a homemade vacuum manifold device and polymerized in parallel under UV irradiation. The experimental setups for the polymers preparation are shown in Figure 14.  
The different binding parameters were evaluated using impiramine as a pharmaceutical test compound obtaining high recovery and good reproducibility. To demonstrate the analytical potential of the chip-based SPE system with real-world samples, human urine and P450 drug metabolism incubation mixture samples were tested. The results suggest that the chip-based monolithic columns are applicable to SPE cleanup of real-world biological samples. Although in this work the authors used an array of eight SPE columns on a polymer-based substrate, they anticipated that an array of 96 (8 \(\times\) 12) or 384 (16 \(\times\) 24) monolithic columns in a polymer device could be developed and used for a larger number of samples.