Novel Magnetic Molecularly Imprinted Polymer (MMIP) Based on a Magnesium-Aluminum Layered Double Hydroxide for the Selective Dispersive Micro-Solid-Phase Extraction (SPE) of Fenitrothion with Analysis by Ion Mobility Spectrometry

A novel magnetic molecularly imprinted polymer (MMIP) based on magnesium-aluminum layered double hydroxide was synthesized and employed for the selective dispersive micro-solid phase extraction of fenitrothion prior to its determination using ion mobility spectrometry. The characterization of the prepared MMIP was performed using x-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, thermal gravimetric analysis, vibrating sample magnetometry, and field emission scanning electron microscopy (FE-SEM). The adsorption capacity of magnetic layered double hydroxide modified with molecularly imprinted polymer (mag-LDH@MIP) was 24.0 mg g−1. The factors affecting extraction efficiency were optimized. Using the optimized conditions, the developed method provided favorable linearity (5.0–200.0 μg L−1), a low limit of detection (1.1 μg L−1), and a high preconcentration factor (67). The values for the intra- and inter-day relative standard deviation (n = 5) for fenitrothion were 3.3 and 4.5%, respectively. This developed method was successfully employed to determine trace quantities of fenitrothion in food and water.