## 4 Molecular Imprinted Polymer in Solid Phase Extraction (MISPE)
### Online Modes
The high pressure of the online system when the column is loaded with nano-sized materials and the addition of an easily damaged SPE column are also downsides of the online mode approach. A strategy for controlling the drawbacks of column-based SPE has been proposed [95]. Over the last two decades, magnetic solid phase extraction (MSPE) methods based on magnetic adsorbents have become one of the most extensively used methods for separating and extracting organic, inorganic, and bioactive species at the matrix level. The MSPE method is based on the adsorption and desorption of analytes on magnetic adsorbents added to the analyte-containing sample solution. Magnetic particles are used to modify various types of polymers, nanomaterials, metals, and metal oxides that can be used as adsorbents in this process. Adsorbents that do not have magnetic characteristics are given magnetic properties in this method. During the process, the magnetic sorbent is added into the sample solution containing the analytes. In order to adsorb the analytes on the sorbent, the sorbent with the sample solution is allowed to interact for a certain period of time. The resulting mixture consists of the sample solution, and the magnetic sorbent is mixed for a certain amount of time in order to make the interaction more effective, faster, and simpler. The sorbent is isolated from the sample solution by an external magnetic field after the completion of the adsorption process. Next, an eluent is added to the sorbent for the elution of the target analytes, and the sorbent is isolated from the eluent phase by an external magnetic field. The concentration of target analytes in the eluent phase is then analyzed by a suitable detection system [101]. [PERSON] et al. in 2009 reported an important application of the online MSPE, whereby they fabricated a poly(dimethylsiloxane)(PDMS)/glass hybrid microchip for online SPE and electrophoresis separation of the trace amounts of fluorescence isothiamate (FITC)-labeled phenylalanine (Phe). The extraction phase was prepared by modifying the magnetic microspheres with hydroxyl-terminated poly-dimethylsiloxane (PDMS-OH), and conveniently immobilized into the SPE channel by a magnetic field. In this system, the injection of the sample solution into the SPE channel (PDMS-OH microspheres bed) and desorption of analyte from the sorbent phase into the electrophoresis channel was electrically driven [102]. According to [PERSON] et al. [103], molecularly imprinted solid-phase microextraction (MI-SPME) has become one of the most popular sample preparation techniques, and it is now widely employed in analytical laboratories. Incorporating molecular imprinting technology into the SPME appears to be a perfect way to offer selectivity to the extraction process while maintaining the SPME's ease of operation and solvent less nature. During the last few years, there has been a lot of study into developing ways for preparing MIP-based fibres. These procedures have been aimed at obtaining two types of MIP fibres: MIP-coated fibres and MIP monoliths. The detail of selected works in the area of MISPE were tabulated in Table 2.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Template**} & \multirow{2}{*}{**Analyte**} & \multicolumn{2}{c}{**Monomer/**} & \multirow{2}{*}{**Polymerization**} & \multirow{2}{*}{**Template**} & \multirow{2}{*}{**MISPE**} & \multirow{2}{*}{**SPE Condition**} & \multirow{2}{*}{**Asorption**} & \multirow