# Supramolecular Materials as Solid-Phase Microextraction Coatings in Environmental Analysis
## 3 Metal-Organic Frameworks
### MOFs as SPME Coatings for Environmental Applications
#### 3.3.5 Extraction of Pharmaceutical and Personal Care Products  
Pharmaceutical and personal care products (PPCPs) are emerging pollutants with potential detrimental effects on human health, the environment, and ecosystems. Their widespread use, inappropriate disposal, and incomplete removal by conventional wastewater treatment procedures have led to their ubiquitous presence in all the environmental compartments. Due to their presence at trace or sub-trace levels in various environmental matrices and their different physical and chemical properties, the development of a reliable method for their monitoring is still a challenging issue [74]. In this context, new MOF-based coatings for the detection of nonsteroidal anti-inflammatory drugs and anti-cancer drug residues have been reported by the research group of [PERSON] and [PERSON] [75; 76]. In particular, a zirconium-based MOF and graphene oxide nanocomposite coating (Zr-MOF@GO) was synthesized by hydrothermal reaction and deposited onto SS wires by means of an aluminum chromium phosphate binder and applied for the DI-SPME-GC-FID determination of ibuprofen and diclofenac [75]. The extraction mechanism of the hybrid material was based on free-metal site coordination, hydrogen bond formation, and \(\pi\)-\(\pi\) interactions, achieving LOQs of 10 and 100 ng/L, respectively. Finally, the method was applied for the quantitation of the investigated drug residues in a Yellow River water sample, obtaining similar results to those achieved using a commercial PA fiber, i.e., an ibuprofen concentration of 27 ng/L and a diclofenac concentration below the LOQ. [PERSON] and coworkers [76] developed electrospun polyfam/Co-MOF-74 composite nanofibers for the thin-film SPME extraction of sorafenib, dasatinib, and erlotinib, used as anti-cancer drug representatives. The Co-MOF-74 particles were obtained by the hydrothermal procedure and deposited onto the SS fibers by electrodeposition using polyfam as a conductive polymer. The incorporation of the MOF within the polyfam fiber network produced a significant increase in both the surface area and total pore volume compared to the pure polyfam electrospun fibers (28.3 m\({}^{2}\)/g and 0.244 cm\({}^{3}\)/g vs. 8.4 m\({}^{2}\)/g and 0.044 cm\({}^{3}\)/g), thus improving the extraction efficiency toward the anti-cancer drugs. The optimized thin-film-SPME-HPLC-UV method was validated, obtaining EFs in the 24.2-37.1 range and allowing for the quantitation of the analytes at the sub-\(\upmu\)g/L level. Finally, the analysis of environmental water samples revealed a high level of contamination, being that the concentration levels of the detected analytes were always higher than 10 \(\upmu\)g/L. Linear and cyclic methylsilicanes are another class of contaminants of emerging concern, being used in the formulation of PPCPs to improve their physical properties and as precursors of silicone polymers. To improve the detection of these pollutants in wastewater samples, both a MIL-101-based and a CIM-80(Al)-based coating were recently proposed by [PERSON] et al. and by [PERSON] and coworkers [77; 78]. The MIL-101-based fiber was obtained by SS fiber dip-coating in a solution containing MIL-101 and polysulfone [77] and an HS-SPME-GC-MS method was validated for the extraction of oc  
Figure 5: Schematic representation of the synthesis and deposition of dual-functionalized MIL-101-DETA-F onto SPME fibers, reprinted with permission from [73]. tamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecylcyclohexasiloxane from environmental water samples. Under optimal conditions, the MIL-101-based method provided LOQs in the 140-270 ng/L range and RSDs \(\leq\) 4%. The extraction performance of the developed coating was better or equal to those obtained by using a commercial 65 \(\upmu\)m PDMS/DVB fiber, which was affected by high background contamination.