| Non-imprinted polymers were prepared from several functional monomers and a cross-linker: N-phenylacrylamide (PAM) yielded a cross-linked polymer with the highest affinity for ochratoxin A (OTA) in a variety of media. With water flowing at 0.5 mL/min, the condition of solid phase extraction was optimized using OTA in methanol/acetic acid (99:1 v/v) to achieve nearly 100% binding. Pulsed elution (PE) using methanol/triethylamine (99:1 v/v) was good for the quantitative desorption of OTA.; An OTA molecularly imprinted polymer (MIP) was synthesized using PAM. A molecularly imprinted solid phase extraction and pulsed elution (MISPE-PE) method was developed for the rapid analysis of wheat extracts for OTA. The MISPE-PE peak area was linearly related (R2 = 0.9973) to the mass of OTA. This method with fluorescence detection afforded a detection limit of 5.0 ng/mL. Recovery of OTA from wheat extracts was 103 +/- 3%.; A rapid analytical method for the determination of ochratoxin A (OTA) in red wines was developed using online molecularly imprinted solid phase extraction, pulsed elution and ion-pair high performance liquid chromatography (MISPE-PE-HPLC) with fluorescence detection. An alkaline mobile phase (CH3CN/NH4OH, 15:85, v/v, pH = 9.8) for HPLC was employed to enhance OTA fluorescence, reproduce the short retention time of 3.65 min, and achieve a good separation of OTA from wine matrix components. This new method offered a detection limit of 0.05 ng/mL, a recovery of 89 +/- 4% from red wines, and a fairly linear calibration curve (R2 = 0.9966) up to 100 ng/mL. Spartan software was used to predict the interactions between OTA and functional monomers using the atomic charges and the heats of formation. |
