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Highlights • A single step QuEChERS method for analysis of 47 pesticides in chili products. • Multi-factor optimization was evaluated by recoveries and matrix effect. • MWCNTs and PSA were mixed with optimized salts as cleanup sorbents. • Validation data of the method demonstrated its great performance. • The method was applied in routine pesticide analysis with real samples. Abstract A novel rapid single-step cleanup method combined with quick, easy, effective, rugged, and safe (QuEChERS) extraction approach for determining multi-pesticide residues was developed. For the single-step QuEChERS (sin-QuEChERS) cleanup procedure, a specified cartridge was fitted within an extraction centrifuge tube for removing non-target substances. Multi-walled carbon nanotubes (MWCNTs) and Primary Secondary Amine (PSA) mixed with salts functioned as absorbents. Method validation was applied on 47 representative pesticides in pepper, chili peppers and chili sauce by LC-MS/MS and GC–MS/MS detection. Compared to the original QuEChERS method, the Sin-QuEChERS method was fast and convenient without any further vortex or centrifugation. Satisfactory recoveries of most pesticides at two concentration levels were in the range of 70–120% (except for pyrimethanil) with relative standard deviations (RSDs n = 5) lower than 17%. The limit of quantification (LOQs) for the 47 pesticides were 0.01 mg/kg in three matrices. Sin-QuEChERS method was successfully applied to monitor the market multi-residues. [ABSTRACT FROM AUTHOR]

A multi-residue method was developed for the determination of 124 pesticide residues in Chinese liquor and liquor-making raw materials (sorghum and rice hull) by rapid Multi-plug Filtration Cleanup (m-PFC) and GC–MS/MS detection. Different combination and proportion sets of sorbents were initially optimized for each matrix with a dispersive solid-phase extraction (d-SPE) procedure. Satisfactory linearity was obtained for the 124 pesticides with regression coefficients (R 2 ) greater than 0.9901. Mean recoveries of 121 pesticides were in the range of 71–121% with Relative Standard Deviations (RSDs) lower than 16.8% except cyprodinil, diflufenican and prothioconazole. The Limit of Quantification (LOQs) was in the range of 1.0 × 10 −4 –5.0 × 10 −3 mg kg −1 and the Limit of Detection (LODs) ranged from 3.0 × 10 −5 to 1.5 × 10 −3 mg kg −1 for the 124 pesticides in the matrices. It is demonstrated the m-PFC procedure is superior to the d-SPE method and it could be used to routinely monitor of pesticide residues in market samples. [ABSTRACT FROM AUTHOR]

A sensitive and specific method for the determination of glufosinate in plant origin foods was developed. The method involves extraction using modified QuPPe method, clean-up by multi-walled carbon nanotubes (MWCNTs), derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) and detection with liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). The method was validated on twelve matrices spiked at 10 or 20, 100 and 500 μg/kg. The recovery ranged from 80% to 108% with intra-day RSDs ( n = 5) of 0.6–9.8% and inter-day RSDs ( n = 15) of 3.0–9.4%. Good linearities ( R 2 ⩾ 0.9991) were obtained for all matrices. The limit of detection (LOD) and limit of quantification (LOQ) for the selected matrices ranged from 0.3 to 3.3 μg kg −1 and from 1 to 10 μg kg −1 , respectively. The method was demonstrated to be reliable and sensitive for the routine monitoring of glufosinate in plant origin foods. [ABSTRACT FROM AUTHOR]

Rosa rugosa is extensively cultivated in China for its remarkable fragrance and flavor, however, the metabolic changes in roses during growth and drying remain unclear. Our results revealed significant variations in phenol and flavonoid contents and antioxidant capacity in roses (Rosa rugosa f. plena (Regel) Byhouwer) under different conditions. Phenol contents were positively correlated with antioxidant capacity, with phytochemicals being most prominent in unfolded petals. The highest antioxidant capacity and phenol and flavonoid contents were observed in April. Considering their greater consumption value, whole flowers were more suitable than petals alone. Furthermore, considerable sensory and nutritional differences were observed in dried roses. Different drying methods increased their total phenol content of roses by 4.2–5.4 times and the antioxidant capacity by 2.9 times. Metabolomics revealed the altered contents of flavonoids, anthocyanins, lipids, amino acids, and saccharides. This study provides baseline data for the potential of roses as a natural source of antioxidants in the food and pharmaceutical industries. [Display omitted] • Bioactive chemicals in rose showed the highest level at the preanthesis stage. • Terpenes were the most volatile metabolites in roses during daytime. • Stamens had a much higher flavonoid content than petals and receptacles. • An increase in anthocyanin content maintained the desired appearance of freeze–dried roses. [ABSTRACT FROM AUTHOR]

Residue levels of dichlorvos, fenitrothion, pirimiphos-methyl, malathion and deltamethrin during sorghum distilled spirits production were examined. The analytical method for these pesticides in sorghum, fermented sorghum, rice hull and distilled spirits was validated through linearity, matrix effect, accuracy and precision, limit of quantification (LOQ) and limit of detection (LOD) parameters. The pesticide residue levels before/after each process of soaking, steaming, fermentation, and distillation were determined by gas chromatography coupled with tandem mass spectrometry (GC–MS/MS). Results showed that soaking process could obviously reduce dichlorvos residue with 87% decrease as its high vapor pressure. The steaming process reduced pesticide residues by 42–83% mainly due to evaporation or thermal degradation. Also, the fermentation could remove pesticide residues by 40–63% in favor of biological degradation. Moreover, the distillation process was proved to be effective for decreasing the pesticide residues in distilled spirits with the processing factors lower than other processes for each pesticide. [ABSTRACT FROM AUTHOR]