ABSTRACT
A novel electropolymerized molecularly imprinted polymer (MIP) film, based on diosgenin on a glassy carbon electrode (GCE), has been synthesized. Based on density functional theory (DFT), para-aminobenzoic acid (pABA), which is a green substance, was selected from five functional monomers by Gaussian software for MIP production, to be the suitable monomer. The MIP's synthesis conditions were optimized, and the imprinting effect was confirmed by comparing the electrochemical reaction of MIP, with that of non-imprinted polymer (NIP). The calibration curve of diosgenin on MIP/GCE was obtained with a linear range of 0.003 to 0.13â¯mM. The limit of detection (LOD) and limit of quantification (LOQ) were determined to be 8.95â¯×â¯10-4â¯mM and 2.98â¯×â¯10-3â¯mM, respectively. This method exhibited good stability, high sensitivity, and high selectivity for diosgenin. The developed method is the first method reported to be used for the electroanalysis of diosgenin, and it has been successfully applied to the analysis of diosgenin in Trigonella foenum graecum seed extract.
Subject(s)
4-Aminobenzoic Acid/chemistry , Biosensing Techniques , Computer-Aided Design , Diosgenin/chemistry , Molecular Imprinting , Polymers/chemistry , Biomarkers , Calibration , Carbon/chemistry , Diosgenin/blood , Electrochemical Techniques , Electrodes , Green Chemistry Technology , Limit of Detection , Normal Distribution , Reproducibility of Results , Software , Trigonella/chemistryABSTRACT
Pesticides are considered as the most polluting substances. The residue of pesticides in agricultural crops, especially in greenhouse harvests, has been reported critical. Cucumber, considered as a vegetable, is an agricultural product which is commonly found in the Iranian food basket. The current study aims to assess the level of diazinon and oxydemeton-methyl existing in cucumbers sampled from Kerman greenhouses. The pesticide residue was extracted by acetone and dichloromethane. The extracts were cleaned up according to the solid-phase extraction method. The pesticide residues were then determined by capillary gas chromatography with nitrogen-phosphorus detection. The recoveries were 83 and 85 %, the limit of detection was 0.028 and 0.034 mg/kg, and the limits of qualification were 0.093 and 0.113 mg/kg for diazinon and oxydemeton-methyl in cucumber samples, respectively. The median of diazinon residue was detected 0.582 mg/kg, which was 11.64 times the national maximum residue limit (MRL) (0.05 mg/kg), and the median for oxydemeton-methyl was 1.910 mg/kg, being 1.91 times the MRL (1 mg/kg).
