Conference information: Abstracts, 15th Iranian Chemistry Congress

Abstract: Sorbic acid and its salts are most commonly used to inhibit the activity of a wide range of fungi, yeasts, molds and bacteria [1,2]. However, excessive addition of the preservatives may be harmful to consumers and cause some symptoms of urticaria, asthma, intolerance [3], etc. So the maximum permitted concentrations of preservatives in food products have been regulated in many countries [4,5]. The aim of this work is the electrosynthesized molecularly imprinted polypyrrole (PPy) films for selective extraction of sorbate ions (Sor) by electrochemically controlled solid-phase microextraction (EC-SPME) system. The film was prepared by doping of sorbate ion as a dopant anion during the electropolymerization of pyrrole (PPy-Sor) onto a stainless steel wire in aqueous solution. Scanning electron microscopy (SEM) has confirmed the nanostructure of the PPy-Sor film. The sorbent behavior of PPy-Sor is characterized using spectrophotometry analysis. The advantages of using PPy-Sor fiber in this particular EC-SPME application have been evaluated by comparing the analytical performance of the PPy-Sor with an analogous fiber that was prepared by a spherical anion dopant (ClO4 -) in the same conditions. The effect of pH, uptake and released time, uptake and released potentials, template concentrations, and interference on the performance of the PPy-Sor fiber was investigated and optimized. The PPy-Sor selectivity was evaluated by checking several anions.The PPy-Sor fiber demonstrated improved selectivity coefficients for EC-SPME and spectrophotometry determination of benzoate and salicylate ( K^EC-SPME_Sor,Bz = 1.3 x 10 -2 , K^EC-SPME_Sor,Sal = 2.6 x 10 -3 ). The figures of merit of the proposed method include of good linearity (R2> 0.9927), reproducibility of fibers with R.S.D. < 6%, (n = 3). The calibration graphs were linear in the range of between 8×10-6 - ?.1×10-? mol L-1 and detection limits were 4.9×10-6 mol L-1. The performance of a PPy-Sor as a selective solid-phase microextraction sorbent for the cleanup of the real samples such as beverage samples is described
Template and target information: sorbic acid

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