[QuEChERS-liquid chromatography-tandem mass spectrometry for determination of 22 triazole pesticide residues in Chinese herbal medicines].

Eight well-known herbals in Zhejiang Province, Zhebawei, are commonly used as traditional Chinese herbal medicines owing to their rich active ingredients. However, the unavoidable use of pesticides during agricultural production has led to pesticide residue problems in these herbs. In this study, a simple, rapid, and accurate method was established to determine 22 triazole pesticide residues in Zhebawei.

Stereoselective behaviors and enantiomeric effects of paclobutrazol on microorganisms during Chinese cabbage pickling process.

Studies on the differences between chiral pesticide enantiomers have caused widespread concern in the last decade. In the current work, the selective behaviors and different biological activities of paclobutrazol enantiomers during Chinese cabbage pickling process were evaluated. Results of degradation kinetics indicated that when paclobutrazol reside in raw material (Chinese cabbage) and was introduced into the pickling process, the degradation rates of the two paclobutrazol enantiomers were significantly different, the half-lives of (2R, 3R)-paclobutrazol (R-paclobutrazol) and (2S, 3S)-paclobutrazol (S-paclobutrazol) were 18.

Magnetic covalent organic framework as a solid-phase extraction absorbent for sensitive determination of trace organophosphorus pesticides in fatty milk.

A simple and efficient magnetic solid-phase extraction (MSPE) method was established with magnetic covalent organic framework (COF) as adsorbent to enrich organophosphorus pesticides from fatty milk samples, followed by the sensitive determination via LC-MS/MS. The key parameters influencing the MSPE efficiency were comprehensively investigated to afford an optimized procedure. All the target analytes could be captured directly by magnetic COF from milk without protein precipitation, making the pretreatment rapid and convenient.

High-throughput determination of fungicides in grapes using thin-film microextraction coupled with liquid chromatography-tandem mass spectrometry.

A high-throughput and environmentally friendly method based on 96-well plate thin-film microextraction was established to determine 14 fungicides in grapes and grape juice using liquid chromatography-tandem mass spectrometry. The thin-film microextraction optimized method consisted of 60 min of extraction at pH 6.0 with the addition of sodium chloride (2-5%).