A First Tentative for Simultaneous Detection of Fungicides in Model and Real Wines by Microwave Sensor Coupled to Molecularly Imprinted Sol-Gel Polymers

Abstract

A molecularly imprinted silica (MIS) coupled to a microwave sensor was used to detect three fungicides (iprodione, procymidone and pyrimethanil) present in most French wines. Chemometric methods were applied to interpret the microwave spectra and to correlate microwave signals and fungicide concentrations in a model wine medium, and in white and red Burgundy wines. The developed microwave sensor coupled to an MIS and to its control, a nonimprinted silica (NIS), was successfully applied to detect the three fungicides present in trace levels (ng L−1) in a model wine. The MIS sensor discriminated the fungicide concentrations better than the NIS sensor. Partial Least Squares models were suitable for determining iprodione in white and red wines. A preliminary method validation was applied to iprodione in the white and red wines. It showed a limit of detection (LOD) lower than 30 ng L−1 and a recovery percentage between 90 and 110% when the iprodione concentration was higher than the LOD. The determined concentrations were below the authorized level by far.

The Use of Computational Methods for the Development of Molecularly Imprinted Polymers

“…In other cases, multivariate methods have been used to reveal correlations hidden in the data obtained when evaluating MIPs. Different combinations of PCA and PLSR methods have been applied for interpretation of MIP binding data obtained from SERS (surface-enhanced Raman spectroscopy) [ 635 , 636 , 637 , 638 , 639 , 640 , 641 , 642 , 643 , 644 ], for pattern recognition in the responses from various MIP-sensor arrays [ 645 , 646 , 647 , 648 , 649 , 650 , 651 , 652 , 653 , 654 , 655 , 656 , 657 , 658 , 659 , 660 ], to correlate the shape of MIP-quartz crystal microbalance frequency curves to different analytes [ 106 , 661 , 662 , 663 ], for cyclic voltammetry measurements on binary mixtures [ 214 , 656 , 664 , 665 ] and for correlating the results with HPLC data [ 665 ] and to process fluorescence data [ 666 ]. PLSR and PCA have also been used to correlate bupivacaine–MIP binding with rebinding solvent properties [ 667 , 668 ] and with polymer morphology and pre-polymerization interactions from MD simulations [ 403 ].…”

Real-Time Detection of Phenylacetaldehyde in Wine: Application of a Microwave Sensor Based on Molecularly Imprinted Silica

“…The use of microwave sensing in a broad range of frequency (10 Mhz to 20 GHz) provides a rich information spectrum, allowing easy quantification of the target molecule in complex matrices such as wine [ 12 ].…”

Raman Studies on Surface-Imprinted Polymers to Distinguish the Polymer Surface, Imprints, and Different Bacteria

“…Thus, one needs to apply multivariate data analysis, such as Partial Least Squares Discriminant Analysis (PLS-DA) . Multivariate data analysis is a powerful tool that has been used previously in combination with MIPs to identify and quantify compounds mostly when using spectroscopic methods, such as SERS, fluorescence, or microwave spectroscopy, but also other techniques including square wave voltammetry for detecting the analyte. It is known that using chemometric tools such as PLS-DA to distinguish bacteria based on Raman spectra in general is feasible. − However, acquiring the Raman spectra of bacteria on polymer substrates leads to a substantial number of additional bands stemming from the substrate.…”