磁固相萃取-气相色谱法检测黄瓜中丙溴磷

复杂样品前处理极大的影响分析结果的准确度和分析过程的时效性,因此建立高效的分离分析方法提高检测的准确性和效率具有重要意义.本研究通过一步水热法,合成了碳包覆四氧化三铁磁性纳米粒子(Fe3O4@C-Magnetic nanoparticles,Fe3O4@C-MNPs),利用透射电子显微镜(transmission el...

Determination of Profenofos in Cucumber by Magnetic Solid Phase Extraction Gas Chromatography

The pretreatment of complex samples greatly affects the accuracy of the analysis results and the timeliness of the analysis process. Therefore, it is of great significance to establish an efficient separation and analysis method to improve the accuracy and efficiency of detection. In this study, Fe₃O₄@C-MNPs with rich functional groups on the surface, uniform particle size distribution and good dispersion were successfully synthesized by an improved one-step hydrothermal method. The magnetic nanoparticles which have good adsorption properties for organophosphorus pesticides (OPs) are superparamagnetic. Using Fe₃O₄@C-MNPs as a magnetic adsorbent, a magnetic solid phase extraction-gas chromatography method was constructed for the quantitative determination of profenofos in cucumber. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer (VSM) were used to observe the morphology, structure and magnetic properties of the materials. The main factors affecting the recovery rate of pesticides in the process of magnetic solid phase extraction (MSPE) were optimized, including the amount of magnetic adsorption materials, extraction time and solution pH. The experimental results showed that Fe₃O₄@C-MNPs had a good adsorption and enrichment effect. The optimal condition is that the amount of Fe₃O₄@C-MNPs magnetic adsorbent is 0.06 g, the solution pH is 6, the adsorption equilibrium time is 10 min, and the eluent is acetone. Under the optimal conditions, the linear range of profenofos pesticide detection was 0.011~1.0 µg/mL, and the detection limit was 0.0011 mg/kg. The synthetic magnetic adsorbent material Fe₃O₄@C-MNPs was used to detect profenofos in actual cucumber samples by magnetic solid phase extraction-gas chromatography. The recoveries ranged from 95.0% to 101.4%, and the relative standard deviation (RSD) was 2.9%-8.5%. This method uses less organic reagents and the adsorbent can be reused. The method reduces the cost of testing and is more environmentally friendly. The testing efficiency is also improved. In addition, the detection results are accurate and reliable.