Selective determination of thidiazuron herbicide in fruit and vegetable samples using molecularly imprinted polymer fiber solid phase microextraction with ion mobility spectrometry detection (MIPF-SPME-IMS)

Abstract

In this study, we use corona discharge ion mobility spectrometry (CD-IMS) as a detection technique for determining thidiazuron (TDZ) after its selective microextraction using molecularly imprinted polymer (MIP) fibers. This is the first time that MIP fiber solid phase microextraction-ion mobility spectrometry (MIPF-SPME-IMS) was used to detect TDZ. The fiber was synthesized simply using a narrow bore silica capillary as a mold by the copolymerization of methacrylic acid–ethylene glycol dimethacrylate imprinted with TDZ. The prepared MIPs were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM). The obtained flexible MIP monolithic fibers have high chemical and thermal stabilities with good selectivity to TDZ. The effective parameters influencing the polymerization were also investigated. In addition, the influences of different factors such as pH, extraction time, desorption solvent, and temperature on the extraction efficiency of the analyte were investigated. Under the optimum conditions, analytical parameters such as linearity, precision and limit of detection were also evaluated. The linear range was in the range of 0.01–20μgL−1 (r2=0.9980) and the limit of detection was 0.005μgL−1. Intra- and inter-day precisions were satisfactory with a relative standard deviation (RSD) of 0.9% and 2%, respectively. Finally, the established MIPF-SPME-IMS method was successfully applied in the selective determination of TDZ residues in fruit and vegetable samples.