## 5 MIP Applications for the Extraction of Antibiotics in Milk
### Amphenicols
The analytes were eluted with 4% acetic acid in methanol (4 mL), the eluate was filtered with a 0.22 \(\upmu\)m filter, evaporated under nitrogen stream and the dry residue was reconstituted with acetonitrile-water (50:50, \(v/v\); 1 mL). In comparison with the respective NIP, MIP adsorption capacity for FFC was higher, with Q\({}_{\text{max}}\) values of 16.2 and 183.1 \(\upmu\)mol/g, while binding specificity study between FF, CAP, cefadroxil (CFD) and rovithromycin showed MIP selectivity over FFC and CAP. Furthermore, the use of microwave-assisted emulsion polymerization reaction used in this paper resulted in reduced required time (1 h) and MIP particles with improved morphological characteristics [52]. A MISPE-high-performance liquid chromatography-mass spectrometry (HPLC-MS/MS) method was developed for the determination of CAP, TAP and FFC in baby formula samples. A mixture of CAP (0.19 mmol), MAA (1.5 mmol), DVB (3.84 mmol), AIBN (0.27 mmol) and acetonitrile-toluene (3:1, \(v/v\); 12.5 mL) was placed inside a temperature controllable incubator at 60 \({}^{\circ}\)C and continuous stirring at 24 rpm for 24 h. The developed MIP particles were washed with acetonitrile and methanol and filtered through a 0.45 \(\upmu\)m nylon membrane. The template was removed by Soxhlet extraction with methanol-acetic acid (1:1, \(v/v\)) for 8 h. CAP-MIPs (0.05 g) were packed into a SPE cartridge, loaded with formula powder extract (1 mL) and washed with 5% acetonitrile in toluene. The analytes were eluted with 1% acetic acid in methanol, the eluate was evaporated at 30 \({}^{\circ}\)C under nitrogen stream and the dry residue was reconstituted in mobile phase. The imprinting effect was studied by comparing the MIPs and the respective NIPs during the sample loading step where a 50% analytes loss was observed with the use of the NIP. Furthermore, the developed method utilized sample deproteinization pre-treatment with ethyl acetate and MISPE clean-up for the extraction and determination of the analytes, while CAPwas used as the template molecule for the simultaneous recognition of three structurally related amphenicols [53]. The same laboratory developed two MIPMME-HPLC-DAD methods for the determination of TAP in milk and honey samples. For the first method, TAP (0.05 mmol) was dissolved in toluene (52 mL) that contained dodecanol (0.31 g) and 4-VP (0.1 mmol) and the mixture was strongly sonicated for 5 h. EGDMA (1 mmol) and AIBN (8.5 mg) were added and the mixture was sonicated for 10 min. The mixture (50 mL) was transferred and sealed inside a micropipette tip and polymerization was carried out at 60 \({}^{\circ}\)C for 24 h. The developed MIP monoliths were washed by pumping methanol with a syringe infusion pump. The TAP-MIP monolith containing micropipette tip was attached to a syringe infusion pump, preconditioned with methanol (5 mL) and water (2 mL), loaded with pre-treated spiked milk extract (5 g) and washed with water (0.5 mL). The analytes were eluted with methanol (0.1 mL) and the eluate was injected directly for analysis. In comparison with the respective NIP, MIP adsorption capacity for TAP was 183.1 ug/g, while binding specificity study between TAP, CAP, and sulfadiazine (SDZ) showed MIP selectivity over TAP and low affinity for CAP and the imprinting factor was 7.5 for TAP [54]. For the second method, CAP-MIP monoliths were developed by following the same preparation protocol. The developed MIP monoliths were washed with methanol. The TAP-MIP monolith containing micropipette tip was attached to a syringe infusion pump, preconditioned with methanol (2 mL) and water (1 mL), loaded with pre-treated spiked milk extract (4 mL) and washed with water (0.5 mL). The analytes were eluted with methanol-water (55:45, \(v/v\); 0.1 mL) and the eluate was injected directly for analysis. In comparison with the respective NIP, MIP adsorption capacity for TAP was 62.72 ug/g and the imprinting factor was 2.46 [55].