A new compound, neoarctin A (1), together with nine known compounds (2–10), were obtained from the ethanolic extract of the seeds of Arctium lappa. The structure of 1 was elucidated on the basis of spectral and chemical evidence.

A novel ultrasound-assisted magnetic solid-phase extraction (UA-MSPE) was developed for the separation/preconcentration of trace amounts of pyrethroids (fenpropathrin, fenvalerate, deltamethrin, and bifenthrin) in Paris polyphylla sample using carbon nanotubes based on Fe₃O₄ magnetic nanoparticles (Fe₃O₄@CNT MNPs), and high-performance liquid chromatography-UV is described. High recoveries of pyrethroids were obtained at a low MNPs concentration because sonication enhances the contact chances between magnetic nanoparticles and extractable analytes and promotes the extractability of the MSPE process. After the extraction, the adsorbent can be conveniently separated from the sample solution by an external magnet, and the adsorbed analytes were eluted from magnetic Fe₃O₄@CNT. The main factors influencing the extraction efficiency including the amount of the MNPs, the extraction time, the pH of sample solution, the sonicating time, and the desorption conditions were studied and optimized. Under the optimized experimental conditions, a good linearity was observed in the range of 1-100.0 ng mL⁻¹ for all the analytes, with the correlation coefficients (r) ranging from 0.9962 to 0.9991. The limits of detection of the four pyrethroids are 0.53, 0.26, 0.47, and 0.67 ng mL⁻¹, respectively. The recoveries of the method were in the range between 85.5% and 93.2%. This method is much faster and more effective than traditional SPE methods, and it is promising for the analysis of pyrethroids residues.

Formaldehyde (HCHO) is a widespread air pollutant in the indoor environment. Previous studies have shown that some bacteria have potential application to remove indoor HCHO. The purpose of this study is to evaluate the effectiveness of Methylobacterium sp. strain R1 (S‐R1) in removing formaldehyde (HCHO) from indoor air using biofilters. Three experiments confirmed S‐R1’s ability to degrade HCHO in the air, with ¹³C‐NMR analysis revealing its involvement in the metabolic process. Optimal biofilter parameters, including 35 sponge layers, 30% humidity, and 9.50 m³/min air flow, resulted in a removal efficiency of up to 90% and an elimination capability of 24111‐27000 μg/(m³∗h) during a 60‐minute test period. Long‐term (31‐day) operation of the biofilter with the optimal parameters effectively reduced HCHO levels from 1.60 mg/m³ to 0.02‐0.03 mg/m³, below China’s national standard, and maintained this level. Fluorescence microscope observation and downstream gas detection revealed stable S‐R1 cell numbers and no bacterial leakage, respectively. Two conclusions can be drawn: (1) S‐R1 is effective in removing HCHO in polluted air and (2) with optimum parameters, the S‐R1 biofilter is engineering effective in purifying the indoor air environment.