## 5 MIP Applications for the Extraction of Antibiotics in Milk
### Cephalosporins, Macrolides and Sulfonamides
Magnetic CNTs-SMO-MIPs (100 mg) were added into pretreated spiked milk extract (20 mL) and the mixture was kept for 1 h. The MMIPs were collected by means of a magnet and the supernatant was discarded. The analytes were eluted with methanol-acetic acid (9:1, \(v/v\)), the eluate was reduced and the residue was reconstituted with acetonitrile (1 mL). In comparison with the respective NIP, MIP adsorption capacity for SMO was higher, with Q\({}_{\text{max}}\) values of 864.9 \(\upmu\)g/g, while binding specificity study between SMO, SMZ, sulfadimethoroxine, sulfararazine and sulfameter showed MIP selectivity over SMO and the imprinting factors were 10 for SMO, 1.7 for SMZ, 1.9 for sulfadimethoroxine, 2.3 for sulfararazine and 1.5 for sulfarameter [86]. A PMME-HPLC-PAD method was developed for the determination of SMO. SMO (0.05 mmol) dissolved in acetonitrile (400 \(\mu\)L) was mixed with AM (0.1 mmol) and 4-VP (0.1 mmol) and mixture was sonicated for 4 h. EGDMA (1 mmol) and AIBN (9.7 mg) were added and was degassed under nitrogen stream for 10 min. The mixture (50 \(\mu\)L) was transferred and sealed inside a micropipette tip and polymerization was carried out at 60 \({}^{\circ}\)C for 24 h.  
The template was removed by incubation in methanol. The developed MIP monolith containing micropipette tip was connected to a syringe that was employed for the sample loading, washing and elution steps. The SMO-MIP monolith was preconditioned with acetonitrile (2 mL) and water (1 mL), loaded with pretreated milk extract (5 mL) and washed with water (0.5 mL). The analytes were eluted with acetonitrile (0.1 mL) and the eluate was injected directly for analysis. The developed magnetic SMO-MIPs could be reused for five extraction cycles [87]. A SBSE-HPLC-UV method was developed for the determination of trimethoprim, SMZ, sulfararazine and sulfameter in urine, plasma and milk samples. Trimethoprim (290.4 g) and MAA (0.34 mL) were dissolved in acetonitrile (20 mL) and the mixture was stored for 12 h at room temperature. EGDMA (2.26 mL) and AIBN (90 mg) were added and the mixture was degassed under sonication for 5 min. A silylated glass capillary was introduced into the mixture (1.5 mL) inside a test tube and polymerization was carried out at 60 \({}^{\circ}\)C for 2 h. The procedure was repeated for seven times until a coating of 21.5 \(\upmu\)m thickness was acquired. A magnetic core was sealed inside the glass capillary which was then coated with a 2-cm thick coating. The template was removed by incubating the developed MIP coated stir bars in methanol-acetic acid (9:1, \(v/v\)). A trimethoprim-MIP coated stir bar was introduced in pretreated spiked milk extract (10 mL) and extraction was carried out under stirring at 500 rpm for 45 min. The stir bar was collected and analytes were eluted with acetonitrile-phosphoric acid (20:80, \(v/v\)) and sonication for 2 min. The extraction capacity of the MIP-coating was found 1.7 times higher than the NIP-coating [88]. All the reported applications are summarized in Table 5.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Analytic** & **Matrix** & **MP Composite** & \begin{tabular}{c} **Polymerization** \\ **Technique** \\ \end{tabular}  & \begin{tabular}{c} **Template-Monomer-Cross** \\ **Linker** \\ \end{tabular}  & \begin{tabular}{c} **Extraction-Analysis** \\ **LOD**, **LOQ-CC\({}_{\text{av}}\) CC\({}_{\text{B}}\)** \\ \end{tabular}  & **Recoveries (\%)** & **Ref. ** \\ \hline \hline CFL & milk & CFL-MIPs & \begin{tabular}{c} built \\ polymerization \\ \end{tabular}  & CFX-TFMA-ECDMA & MISPE-HPLC-UV & - & 91.78–93.25 & [84] \\ \hline CFL, CFP & milk & \begin{tabular}{c} tributly/ammonium \\ CFQ-MIPs \\ \end{tabular}  & - & \begin{tabular}{c} tributly/ammonium \\ CFQ-MA-ECDMA \\ \end{tabular}  & \ \begin{tabular}{c} MISPE-HPLC-UV \\ \end{tabular}  & - &
\begin{tabular}{c} - \\ \end{tab