A rapid and efficient magnetic solid phase extraction (MSPE) method, based on Fe3O4@β-cyclodextrin–lipid bilayer nanocomposites (Fe3O4@β-CD–LB), was built. The MSPE method coupled with GC-QTOF-MS has been designed for the trace detection of nine organochlorine pesticides (OCPs) in soil samples. The Fe3O4@β-CD–LB was successfully synthesized and characterized by vibrating sample magnetometry, Fourier transform infrared spectrometry, transmission electron microscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. In this experiment, the OCPs in the soil samples were firstly extracted with n-hexane/dichloromethane (v/v 1 : 1) at high pressure and temperature, and then subjected to MSPE for adsorption and purification. Considering the synergy effect between host–guest inclusion complexation and hydrophobic interaction in the adsorption mechanism, the bi-functionalized magnetic nanocomposites exhibited excellent adsorption properties for the OCPs and natural resistance to interference by macromolecules. Under the optimum experimental conditions, the method showed wide linear ranges with low limits of detection (4.5 to 34 pg g−1). The results showed that the mean recoveries of the OCPs in the soil samples were 78–107% with 3.0–6.1% intra-day relative standard deviation (RSD) and 3.5–6.9% inter-day RSD. The method has been applied for the determination of the OCPs in actual samples, and ΣOCPs ranged between 0 and 2.3 ng g−1 in seven soil samples.
An in vivo solid-phase microextraction (SPME) fiber with high-coverage capture capacity of plant endogenous substances based on the porous covalent triazine framework (CTF) material was developed. The CTF fiber coupled with gas chromatographic quadrupole time-of-flight mass spectrometer (GC-QTOF-MS) analysis was used for monitoring untargeted endogenous metabolites in living Chinese cabbage plants ( Brassica campestris L. ssp. chinensis Makino (var. communis Tsen et Lee)). A total of 100 endogenous substances were identified, mainly including aldehydes, ketones, acids, alcohols, phenols, alkanes, alkenes, esters, isorhodanates, nitriles, as well as indole and its derivatives. Using the in vivo metabolites analysis method, Chinese cabbage plants at different growing stages demonstrated significantly statistical differences in plant metabolism. In addition, metabolic dysregulation of Chinese cabbage plants under fipronil pesticide contamination was observed. To summarize, the proposed approach provides a feasible method to capture metabolic information in living vegetables and for risk assessment of pesticide use during agricultural production.
危险品化学品经营许可证（带存储）