# Preparation of Magnetic Polymers for the Elimination of 3-Isobutyl-2-methoxypyrazine from Wine
## 4 Conclusions  
Magnetic polymers were synthesised (including in a microwave), characterised, and found to remove up to 40% or more of the IBMP in model wine solutions and two white wines. Langmuir and Freundlich isotherm models were used to evaluate polymer binding properties within practical ranges of IBMP concentration in model wine. No difference in comparison to conventional synthesis was observed for the microwave polymers in the adsorption of IBMP from model wine and in physical characters by SEM and FTIR analysis. Furthermore, the addition of the magnetic substrate had no effect on the physical characters and binding properties of the polymers. The easy separation, reasonable adsorption ability towards IBMP, and regeneration ability make magnetic polymers an attractive potential option to remediate wines with elevated MP concentrations. However, the choice of polymer system needs further investigation to improve the specificity of the polymers. Binding of IBMP in model wine and white wine was apparently driven by non-specific hydrophobic interactions and the putatively synthesised molecularly imprinted polymer turned out to be no better at IBMP removal than its non-imprinted counterpart. Two components of the imprinting system could be examined further to improve the specificity. Firstly, the functional monomer could be considered. Compared to MMA, for instance, methacrylic acid has more active carboxylic acid functional groups to interact with the template and reinforce H-bonding [50]. Secondly, the solvent used to prepare the polymers could be optimised. Polymers were prepared using toluene, which acted as a porogen that has a similar size and structure to the target molecule. Thus, it may be that the template did not impart a distinctive enough shape to the polymers [51]. Studies could also include control imprinted polymers prepared with an unrelated template to verify in the event of greater binding that it was from molecular imprinting and not because of physical differences between the polymers [52]. Finally, for the practical usage of MMIPs, examination of the effects of polymers on other wine volatiles, colour parameters, and sensory properties also needs to be further studied. The following are available online, Figure S1: Linear isotherm analysis plots of thermally synthesised magnetic polymers showing (a) Langmuir Type 2 analysis plot of putative magnetic molecularly imprinted polymer (MMIP), (b) Langmuir Type 2 analysis plot of magnetic non-imprinted polymer (MNIP), (c) Freundlich analysis plot of putative MMIP, (d) Freundlich analysis plot of MMIP, (e) Weibull-Radushkevich analysis plot of MMIP, (f) Figure S2: Gas chromatography-mass spectrometry selected ion monitoring chromatograms of white wines showing (a) spiked Australian Sauvignon Blanc, (b) spiked Australian Sauvignon Blanc after putative MMIP treatment, (c) spiked New Zealand Sauvignon Blanc, and (d) spiked New Zealand Sauvignon Blanc after putative MMIP treatment. The following are available online, Figure S1: Linear isotherm analysis plots of thermally synthesised magnetic polymers showing (a) Langmuir Type 2 analysis plot of putative magnetic molecularly imprinted polymer (MMIP), (b) Langmuir Type 2 analysis plot of magnetic non-imprinted polymer (MNIP), (c) Freundlich analysis plot of putative MMIP, (d) Freundlich analysis * [PERSON] and [PERSON] (2012) [PERSON]; [PERSON] Determination of ortho- and retronasal detection thresholds and odor impact of 2,5-dimethyl-3-methoxypyrazine in wine. _J. Food Sci._**2012**, _77_, S394-S398. [CrossRef] [PubMed]
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