Application of GO@ZIF-8 MOF/molecularly imprinted polymer composite for multiple monolithic fiber solid phase microextraction: Determination of illegally added amphetamines in snacks and beverages and quantitation by GC-MS

Abstract

Some adulterated products are marketed to promote weight loss, increase energy or cognition, build muscle, or promote athletic and sexual performance. They may contain undisclosed or mislabeled substances. In this study, a new method for the determination of amphetamine derivatives illegally added to beverages and snacks using a GO@ZIF-8 MOF fiber combined with molecularly imprinted polymer (MIP)/solid-phase microextraction (SPME), followed by gas chromatography-mass spectrometry (GC-MS) analysis is presented. The prepared fiber is characterized by Fourier-transform infrared (FT-IR), X-ray powder diffraction (XRD), and scanning electronic microscope (SEM) techniques. Following optimization of the extraction factors, a linear range between 0.1 and 400 μg L⁻¹ with a coefficient of determination (R²) exceeding 0.9976 was achieved for the specified compounds. Detection limits for amphetamine derivatives were found to be between 0.023 and 0.033 μg L⁻¹. The limits of detection were found to comply with regulatory limits, indicating the sensitivity of the method for routine analysis. This method was effectively utilized to quantify amphetamine derivatives in snakes and beverages samples. The recovery rate exceeded 96.2 %, and the error under 6.7 %, demonstrating the reliability of method. No significant interference from sample matrix components was observed, demonstrating the selectivity of the method.