## 3 MIPs' Applications
### MIPs in Separation Techniques
[PERSON] and co-workers have recently studied the extraction of important drugs from biological samples, such as plasma and urine. They followed a new water-compatible methodology for determination of the analgesic Tramadol from biological fluids, using MISEE as the sample clean-up technique combined with HPLC [97]. The water-compatible imprinted polymer was prepared using MAA as monomers and chloroform as porogen; loading the sample with water at pH 8 and using methanol/acetic acid (10:1, v/v) as elution solvents. The results showed that the recoveries of Tramadol for the spiked human plasma and urine samples were higher than 91% in the range of 10-50 \(\mu\)L\({}^{-1}\). The same methodology was used to extract other drugs from plasma and urine, such as Verapamil, an L-type calcium channel blocker [98] and Bromhexane, a mucolytic agent [99]. MISPE procedure combined with HPLC was also applied to extract Testosterone and Progesterone and other important drugs from urine [100,101,104]. In recent years, MISEE was extensively applied also for the determination of analytes in environmental samples. In particular, phenolic compounds were widely studied for their pronounced toxicity and their wide distribution in several environmental samples. In the last few years, a new class-selective sorbent for SPE to pre-concentrate the environmental pollutants, phenolic compounds, from spiked water samples was developed by [PERSON] _et al._[105]. A MIP was prepared by bulk method using 2,4-dimethylphenol, that has been chosen, because of its low toxicity, as template. Synthesis optimization was done by using three different porogens, chloroform, acetonitrile and toluene and the difference in recognition selectivity of the polymer columns was observed in HPLC system. The SPE methodology was then developed and used to preconcentrate phenolic compounds in the environmental water. The resulting MIP showed good selectivity for 2,4-dimethylphenol, 2,4-dichlorophenol, 4-chlorophenol, 4-methylphenol and phenol. The application of MIP-SPE to environmental water samples confirms the ability of the MIP sorbent to class-selectively isolate phenolic compounds from the complex matrix. On-line MISEE coupled to reversed-phase HPLC was also applied to selective extraction of 4-nitrophenol in real water samples [106]. MISEE was also applied for the extraction of herbicides, so, several MISEEs for Triazine-based herbicides have been reported for different food matrix such as vegetables and fruits, involving extraction of different analytes such as simazine [112], proparagine [113], proparagine methacrylate [114], _etc_. From the examples reported above we can say that MISEE is a competitive analysis procedure compared with traditional solid-phase extraction for the stability \begin{table}
\begin{tabular}{c c c} \hline
**SPE sorbent** & **Recovery (\%)** & **RSD (\%)** \\ \hline N-MIP & 87 & 8 \\ NIP & 12 & 5 \\ RP C18 & 14 & 6 \\ \hline \end{tabular}
\end{table} 
Table 1: Recoveries of nicotinamide spiked pork liver samples using different SPE adsorbents (\(n=3\), spiked level, 49 \(\mu\)g mL\({}^{-1}\)) (Adapted from [96]). and low cost of preparation of the imprinted materials. Today there are already MISPE cartridges commercially available for selective extraction of several molecules [112, 118] which will increase MISPE applications in analytical chemistry. It is well known that template residues are present in the polymer matrix even after exhaustive washing steps and leakage of the template can affect the accuracy of detection in trace analysis. To overcome this bleeding problem the MIP can be synthesized by using a close structural analogue of the analyte as template (also called dummy template) that can capture also the target analyte since very similar cavities are generated [119, 120]. According to a recent work [120], a MIP for 5-nitroimidazole recognition was prepared using a template analogue which was different from the analytes studied, methacrylic acid as monomer and divinylbenzene as cross-linker in chloroform.