In Vivo Contaminant Monitoring and Metabolomic Profiling in Plants Exposed to Carbamates via a Novel Microextraction Fiber

In this study, a biocompatible solid-phase microextraction (SPME) fiber with high-coverage capture capacity based on a nitrogen-rich porous polyaminal was developed. The fiber was used to track the bioaccumulation and elimination of carbamates (isoprocarb, carbofuran, and carbaryl) and their metabolites (o-cumenol, carbofuran phenol, and 1-naphthalenol) in living Chinese cabbage plants (Brassica campestris L. ssp. chinensis Makino (var. communis Tsen et Lee)). A case-and-control model was applied in the hydroponically cultured plants, with the exposed plant groups contaminated under three carbamates at 5 μg mL^-1. Both bio-enrichment and elimination of carbamates and their metabolites in living plants appeared to be very fast with half-lives at ∼0.39-0.79 and ∼0.56-0.69 days, respectively. Statistical differences in the endogenous plant metabolome occurred on day 3 of carbamate exposure. In the exposed group, the plant metabolic alterations were not reversed after 5 days of contaminant-free growth, although most contaminates had been eliminated. Compared with prior nutriological and toxicological studies, >50 compounds were first identified as endogenous metabolites in cabbage plants. The contents of the glucosinolate-related metabolites demonstrated significant time-dependent dysregulations that the fold changes of these key metabolites decreased from 0.78-1.07 to 0.28-0.82 during carbamate exposure. To summarize, in vivo SPME provided new and important information regarding exogenous carbamate contamination and related metabolic dysregulation in plants.