Batch rebinding

Adsorption-desorption kinetics in batch rebinding experiments... 

Column and micro-column Batch rebinding On-line SA Serum Extraction in chloroform Pulses of McCN Pulse of McOH uv [28]... 

L-aspartic acid L-aspartic acid-imprinted chitosan evaluation by batch rebinding experiments Monier et al., 2010... 

This type of interaction has now been used to prepare a variety of imprinted polymers where A-toluoyl-glycyl-L-valine methyl ester acted as chiral template and 3-trifluoroacetylamino-5-(4-styryl)pyrazole 23f as the binding site monomer. In batch rebinding experiments, some of them showed a pronounced enantioselectivity towards rebinding of template (up to a = 2.7). The re-uptake of substrate to the polymers was generally only low. 

These polymers revealed higher uptake of ampillicin 24 compared to the nonimprinted polymer which has been prepared with both functional monomers but no template at all. Batch rebinding studies were undertaken in which around 20% of the template has been offered to the polymer (in relation to the number of free cavities). 

Small scale procedures for the rapid synthesis and screening of large groups of MIPs have been recently developed [7,8], based on the preparation of 50 mg of materials (MiniMIPs) on the bottom of small vials or of 96-well plates [9] and their in situ testing by equilibrium batch rebinding. The preparation of the materials, which represents a scaled down version of the traditional monolith approach (Chapter 15), is outlined in Fig. 1. For each MiniMIP, a corresponding... 

Figure 2 Screening of MiniMIPs (1) in situ template extraction (2) equilibrium batch rebinding.

Once you believe to have exhaustively removed the template, incubate miniMIPs and MiniNPs for the last time with the solvent to be used for the rebinding step. Allow equilibration for 24 hr and then check the supernatants. If no trace of template can be detected you can proceed to the batch rebinding test. 

After complete extraction of the template, the polymers were submitted to equilibrium batch rebinding with a ImM solution of terbutylazine in CH2CI2. The imprinting factors ( mip/ np) of MIPs prepared using MAA and TFM as functional monomers were 11 and 6, respectively. 

The problem here was that the target molecule is very complex and unstable. The results of the rebinding test are shown after 1 and 26 h of equilibration (expressed as peak area values). The absolute absorbance decreased during this time due to template decomposition. 2-Vinyl pyridine appeared to be the most successful monomer based on the equilibrium batch rebinding tests (Fig. 15). The 2-VPY materials prepared on a larger scale and tested as chromatographic stationary phases also exhibited a certain selectivity towards the template (methotrexate, MTX) and its closely related analogues (leucovorin and folic acid) (Fig. 16). 

Table 3 Small-scale Batch Rebinding Experiments for MiniMIPs Prepared using the Drug Lead E (Pe) and Its Structural Analogue F (Pp) as Template...

Think about the final application of the materials you want to prepare or about the way you want to characterize them. If you evaluate the MIPs by batch rebinding, choose partition coefficients or the imprinting factors IF. If you also evaluate them as stationary phases, choose the capacity factors. 

Scheme 10 Testing the enantioselectivity of the selectively chemically modified MIP using batch rebinding studies with the racemic guest molecule.

To extend this strategy to MIPs a well-studied MIP system was used to generate the racemic MIP starting material [12,15,16]. Racemic PAA was imprinted in the standard MAA/EGDMA matrix. This racemic MIP was equilibrated with enantiomerically pure L-PAA and then treated with diazomethane. Esterification presumably reacts with the unprotected D-selective sites. Verification of the enantioselectivity in the modified polymer was carried out using batch rebinding studies (Scheme 10). The polymer was equilibrated with racemic PAA. The observation of enantiomeric excess in the free solution confirms the enantioselectivity of the modified polymer. 

II. ANALYSIS OF SELECTIVITY IN IMPRINTED POLYMERS A. Batch Rebinding... 

The relationship between K and k holds if both batch rebinding and chromatographic methods are under equilibrium conditions, allowing the equations derived for the bateh rebinding method to be converted to the following equations for ehromatographically derived data ... 

Binding isotherms are commonly measured in MlPs from batch rebinding [4,5] or frontal chromatography studies [6-8]. In batch rebinding experiments, a constant weight of polymer is equilibrated with solutions of analyte of varying initial concentration (I) (Fig. 2). Equilibration of the solution typically takes anywhere from 15 min to 24 h and should be independently measured for each new polymer. The... 

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