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A sensitive extraction and instrumental method was established to detect topramezone and its metabolite (M670H05) in maize and animal-origin foods. Two years of field experiments were carried out to study the dissipation dynamics of topramezone in maize straw, and their residue levels of actual samples collected from the supermarket were determined. They were extracted using liquid–liquid extraction (LLE), and ultra-high-performance liquid chromatography–tandem mass spectrometry was used for detection. The limit of quantification was 0.005 mg kg−1. Recoveries ranged between 73.8% and 109.9% at 3 spiking levels with intraday relative standard deviation (RSD) ≤17.7% and the inter-day ≤18.1%, which meets the requirements of SANTE/12682/2019. Dissipation dynamics experiment showed that, the deposition of topramezone in maize straw in Jilin were <0.005–0.62 mg kg−1with 28 days after application. And the residue level of market samples were all less than 0.005 mg kg−1, much lower than the MRLs (range from 0.01 to 0.8 mg kg−1) set by European Union, United States Food and Drug Administration, China, and Canada. This method was effective to analyse the residues of topramezone and M670H05. [ABSTRACT FROM AUTHOR]

A rapid and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry method, in conjunction with multiwalled carbon nanotube purification, was developed to determine the mefentrifluconazole levels in grapes, cucumbers, tomatoes, peppers, wheat, maize, eggs, milk, pork, chicken, and fish. After purification, tandem mass spectrometry of mefentrifluconazole required <3.0 min. Matrix-matched external standard curves were used to quantify the residual mefentrifluconazole. The method meets the requirements of the European Union Document SANTE/11813/2017. Quantification was linear between 5 and 500 μg/kg (R2 ≥ 0.9988), and both the intra- and interday relative standard deviations were ≤13.7%. Analyte recovery ranged from 81.5% to 107.6%. The limit of mefentrifluconazole quantification was 5 μg/kg for all matrices. The method successfully detected and quantified mefentrifluconazole that had been applied to cucumbers and tomatoes grown in a test field. These results imply that the proposed method is effective and reliable for detecting mefentrifluconazole residues in plant- and animal-derived foods. [ABSTRACT FROM AUTHOR]

In this study, an efficient and fast method for the determination of the herbicide mesotrione and its two metabolites [4-methylsulfonyl-2-nitrobenzoic acid (MNBA) and 2-amino-4-methylsulfonylbenzoic acid (AMBA)] in rice, rice plants, rice hulls, water, and soil was developed, using ultra performance liquid chromatography coupled with tandem quadrupole (Xevo TQ-S) mass spectrometry (UPLC-Xevo TQ-S-MS/MS). The recoveries of the compounds were 68.6%–108.4% at different levels. The intra-day relative standard deviation (RSD) ranged from 2.0% to 14.4%, and the inter-day RSD, from 1.9% to 11.4%. The limits of quantification (LOQ) were ranged from 0.146 to 4.545 μg kg −1 for mesotrione, MNBA and AMBA. Dissipation and residual assays with the commercial formulation were conducted at three locations. The dissipation rates of the compounds were fast in rice plants, soil, and water, and residues at harvest were not detected in any of the three localities. [ABSTRACT FROM AUTHOR]

A simple residue analytical method based on the QuEChERS approach and high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) detection was developed for the analysis of fipronil and its three metabolites in cottonseed, cotton plant and soil. The average recoveries of four test compounds from all three matrices were 78.6–108.9% at the level of 0.005 to 0.5 mg/kg, with an RSD in the range of 0.6 to 13.7%. The limit of quantification (LOQ) of the four test compounds ranged from 0.005 to 0.01 mg/kg. The results of the residual dynamics experiments showed that fipronil dissipated rapidly in cotton plants and soil and that oxidation and photolysis were the main degradation pathways. Moreover, the bi-exponential models demonstrated a good fit of the measured data for fipronil in cotton plants and soil, with R2 in the range of 0.8989 to 0.9989. Furthermore, a total of 40 samples of cottonseed from Shandong Province were analyzed, and all of the samples were free from the four test compound residues. [ABSTRACT FROM AUTHOR]

Famoxadone is a widely used chiral fungicide on tomato, apple, and grape. But it is still being employed as a racemic mixture without distinguishing the difference between enantiomers, which often leads to its inaccurate risk assessment. In this study, a rapid, sensitive, and reliable chiral analytical method was developed for famoxadone enantiomers by ultra high performance liquid chromatography/tandem mass spectrometry, optimal separation condition was achieved with Lux Amylose‐1 column using acetonitrile/water (70:30, v/v) as mobile phase at 0.3 mL/min in 6 min. The average recoveries for two enantiomers in all of the matrices at three spiking levels ranged from 89.8 to 109.4%, with relative standard deviation less than 9.5%. The limits of quantification for all enantiomers in tomato, apple, and grape were not more than 4 μg/kg. And the proposed method was successfully applied to investigate the enantioselective degradation of famoxadone enantiomers in tomato, apple, and grape. The data showed that S‐(+)‐famoxadone was preferentially degraded comparing to the R‐(−)‐famoxadone in tomato, apple, and grape. The potential reasons of the enantioselective behavior were also discussed. This study could help in better understanding the environmental fate of famoxadone and the rational use of chiral pesticide in agricultural production. [ABSTRACT FROM AUTHOR]

An effective analytical method for the simultaneous determination of a novel insecticide flupyradifurone and its two metabolites was developed using ultra high performance liquid chromatography with tandem mass spectrometry coupled with a quick, easy, cheap, effective, rugged, and safe procedure. The three target compounds were extracted with acetonitrile and cleaned up with octadecylsilane, and were separated successfully between 1.9 and 3.1 min using an HSS T3 chromatographic column connected to an electrospray ionization source. All the matrix-matched samples at three fortified levels (0.01, 0.05, and 0.5 mg/kg) provided satisfactory recoveries in the range of 70.3-116.5% with relative standard deviations below 18.6%. The limits of quantitation were 10 μg/kg for flupyradifurone and difluoroethylamino-furanone and 100 μg/kg for 6-chloronicotinic acid. The limit of quantification of flupyradifurone was far below the maximum residue limit in the USA. The method is of great significance for establishing maximum residue limits in China. [ABSTRACT FROM AUTHOR]

Oxathiapiprolin is a chiral fungicide used in China for the prevention and treatment of grape downy mildew, but its potential risk could be inaccurately assessed without distinguishing its enantiomers. In this study, an effective and sensitive chiral analytical method was first established for quantification of oxathiapiprolin enantiomers using supercritical fluid chromatography tandem mass spectrometry. Baseline separation for oxathiapiprolin enantiomers was achieved for less than 3 min by using a Lux Cellulose‐2 chiral column with the resolution of 1.51. The elution order of the eluting enantiomers was identified as (−)‐oxathiapiprolin and (+)‐oxathiapiprolin by an optical rotation detector. The grape samples were extracted by QuEChERS method, with the average recoveries of each enantiomer in grapes were in the range of 88.1–111.8% and the relative standard deviations were less than 18.9%. The enantioselective analysis of the dissipation of oxathiapiprolin in field grape samples showed that (−)‐oxathiapiprolin was dissipated faster than (+)‐oxathiapiprolin. The results indicate that this proposed method could provide data support for the risk assessment of oxathiapiprolin in agricultural produces in a more accurate way. [ABSTRACT FROM AUTHOR]

A reliable and efficient method was firstly established for the simultaneous determination of saflufenacil and its metabolites (M800H02, M800H11 and M800H35) in cereals (soybean and corn) and fruits (apple, grape and orange), based on a triple quadrupole liquid chromatography mass spectrometer. The four target compounds were extracted with acetonitrile and purified by Florisil or Florisil with octadecylsilane from the cereals and fruits. Determination of the targets was achieved within 3.5 min by using Shim‐pack GIST C18 column connected to an electrospray ionization source (ESI‐ mode). The method showed excellent linearity (R2 > 0.9984), and the limits of quantitation were 1 µg/kg for all compounds. Average recoveries were in the range of 74.6%–108.1%, with an intra‐day relative standard deviation between 0.9% and 18.3%. The inter‐day relative standard deviation was less than 13.8%. The results demonstrate that this method is convenient for monitoring the residues of saflufenacil and its metabolites in food matrices. Practical applications: Saflufenacil controls many common annual broadleaf weed efficiently, it has been developed and launched into the market by domestic enterprises. Consequently, an analysis method for monitoring saflufenacil in food sample will be urgently needed in China over the next few years. This method provides separation with good specificity within 3.5 min, which is less than previous studies. For the five matrixes, the method presented satisfactory validation parameters in terms of good linearity, low limit of quantitations, and satisfactory accuracy and precision. Therefore, the method established in this study is a valuable tool to overcome gaps in determining saflufenacil and its metabolites in cereals and fruits, in order to accurate evaluation of risk and ensure food safety. [ABSTRACT FROM AUTHOR]

A rapid, effective and sensitive method to quantitatively determine six fungicide residue was developed using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC–MS/MS). The target compounds were extracted by using acetonitrile and the sorbent used for clean-up in this modified QuEChERS analytical method were biochar, multiwalled carbon nanotubes (MWCNT) and graphitized carbon black (GCB). Results indicated that the MWCNT (10 mg) was the most effective sorbent in removing pigment. This method was validated on spinach, tomato, cucumber, celery, lettuce, rape, pakchoi, romaine lettuce and eggplant matrices spiked at three concentration levels of 0.01, 0.1 and 1 mg kg−1. It exhibited recoveries between 73.1% and 118.2% with RSD values below 20%. Matrix-matched calibrations were performed with the coefficients of determination >0.9901 between concentration levels of 0.01–1 mg kg−1. The limit of quantity (LOQ) for six pesticides ranged from 0.0036 to 0.011 mg kg−1. The developed method was satisfactorily applied to determine pesticide residues in market vegetable samples. [ABSTRACT FROM AUTHOR]

In this study, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was used for the simultaneous determination of thifluzamide and difenoconazole in grapes by ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) using a Waters Acquity UHPLC BEH C18 column. To compare the effects of different sorbents for thifluzamide and difenoconazole in grapes, samples were extracted with acetonitrile and cleaned up using five different types of sorbents at the same concentration level (0.1 mg/kg). The method was validated at three fortification concentrations (0.05, 0.1, 0.5 mg/kg) with five replicates in each matrix using 40 mg of primary secondary amine (PSA) + 10 mg of graphitised carbon black (GCB) as clean-up sorbents. The recoveries were between 76.3 and 109.3%, and the RSDr (intra-day precision, n = 5) and RSDR (inter-day precision, n = 15) values ranged from 3.5 to 8.1% and 5.8 to 22.2%, respectively. The limits of quantification (LOQ) for thifluzamide and difenoconazole were 0.07 and 0.04 mg/kg, respectively. The method showed excellent linearity and reliability. The results demonstrated that the method was effective in detecting the two compounds. In this study, we also investigated the dissipation behaviours of thifluzamide and difenoconazole in grapes. The dissipations of thifluzamide and difenoconazole followed the first-order kinetics with the half-lives of 3.9-16.3 days. [ABSTRACT FROM AUTHOR]

An efficient and sensitive analytical method for simultaneous determination of trace amounts of a new insecticide broflanilide and its metabolites (S(PFH‐OH)‐8007 and DM‐8007) residues in five typical Chinese soils (red soil, black soil, fluvo‐aquic soil, cinnamon soil and paddy soil) was developed. The samples were prepared by a modified quick, easy, cheap, effective, rugged, and safe method. The determination of broflanilide and its metabolites was conducted by ultra high performance liquid chromatography with tandem mass spectrometry with an electrospray ionization source in the positive ion mode. This is the first report for the determination of broflanilide and its metabolites in different soils. Broflanilide and its metabolites were extracted from all soils with acetonitrile and purified by a mixture of primary secondary amine and graphitized carbon black. The average recoveries of the three compounds in five types of soil ranged from 85.3 to 111.8% and the relative standard deviations were less than 13.6%. The limit of quantification was 0.1 μg/kg for all three compounds. This method was successfully used to determine broflanilide and its metabolites in five types of soil. The method was validated to be simple and effective for the determination of trace residual broflanilide and its metabolites in five types of soil. [ABSTRACT FROM AUTHOR]

Abstract: The dissipations of afidopyropen and its metabolite in wheat plant and soil were determined using a quick, easy, cheap, effective, rugged, and safe method with ultra‐high performance liquid chromatography and tandem mass spectrometry under a field ecosystem. The limits of quantification were estimated for both target compounds as 0.001 mg/kg. The recoveries of afidopyropen and its metabolite ranged from 94 to 114% (soil), 90 to 109% (wheat seed) and 81 to 91% (wheat straw) at levels of 0.001, 0.01, 0.1, and 2.0 mg/kg with relative standard deviations ≤7%. The results of the residual dynamics experiments showed that afidopyropen dissipated rapidly in wheat plant and soil. Its metabolite initially showed a tendency of rapid increase followed by a decrease in wheat plant but could not be detected in soil. The data showed that the first + first‐order model was more suitable for describing the decline of afidopyropen in wheat and soil. The half‐lives of afidopyropen in wheat plant and soil were 1.65 and 1.21 days, respectively. [ABSTRACT FROM AUTHOR]

A rapid, sensitive and effective supercritical fluid chromatographic-tandem mass spectrometry (SFC-MS/MS) method was developed to analyze thiacloprid for the first time. The SFC-MS/MS conditions were optimized with the ultra-performance convergence chromatography (UPC 2 ) BEH column (100 mm × 3.0 mm, 1.7 μm particle size) and thiacloprid was eluted at 1.22 min in gradient mode with CO 2 /methanol as mobile phase. The 0.1% formic acid in methanol ( v / v ) was used as postcolumn compensation solution to improve sensitivity. The ABPR pressure, flow rate of mobile phase and flow rate of compensation pump were set at 1800 psi, 1.8 mL/min, and 0.1 mL/min, respectively. The average recoveries of thiacloprid in soil at four spiking levels (5, 10, 100, 1000 μg/kg) ranged between 78.8% and 107.1% with relative standard deviations (RSDs) lower than 12.2% and the limit of quantitation (LOQ) was 5 μg/kg. The proposed method can distinctly improve the analysis efficiency by 2–12 times and reduce the solvent consumption by 5%–95% compared with reported methods. It was applied to investigate the dissipation rates of thiacloprid in greenhouse vegetables and soil under different application modes. The half-lives of thiacloprid in cucumber and soil were 9.55–20.44 days and 3.74–9.14 days separately under different application modes, 10.60 days in tomato under foliar spraying. The residues in vegetables under root irrigation were all less than that under foliar spraying. The results could offer useful data for risk assessment of thiacloprid in agricultural production. [ABSTRACT FROM AUTHOR]

The detection frequencies of tefuryltrione, a new type of 4-hydroxyphenyl-pyruvate dioxygenase inhibitor herbicide, are rarely reported, probably because of the paucity of analytical methods. Herein, an effective and sensitive analytical method has been developed to detect tefuryltrione in vegetables (tomato and cucumber), cereals (rice and corn), soil, and water by ultra high performance liquid chromatography coupled with tandem mass spectrometry. Comparisons of the performances of dispersive solid-phase extraction and multiplug filtration cleanup methods were carried out for tefuryltrione in complex matrices. Extraction solvents and purification sorbents were further optimized for dispersive solid-phase extraction. Tefuryltrione was analyzed with electrospray ionization in the positive mode within 2.0 min. Mean recoveries for tefuryltrione were 75.4-108.9% with relative standard deviations less than 11.0% at three fortification levels (10, 100, 500 μg/kg) in the sample matrixes. Limits of quantification ranged from 0.70 to 5.12 μg/kg, and an excellent linearity ( R2 ≥ 0.9902) was obtained for tefuryltrione at concentrations of 5-1000 μg/L. The results showed that the developed dispersive solid-phase extraction method could serve as an effective, sensitive, and robust method for routine monitoring of tefuryltrione residue in plants and environmental samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • The absolute configuration of fluindapyr enantiomers was first confirmed. • SFC-MS/MS was initially developed for detection of fluindapyr enantiomers. • Enantioselective behaviors of fluindapyr in different organs and plants were various. Fluindapyr is a pyrazolamide chiral fungicide of succinate dehydrogenase inhibitor (SDHIs) with two enantiomers. Pesticide enantiomers often exhibit different biological activities, toxicity due to their different enantioselectivity. Therefore, it is important to separate fluindapyr enantiomers and assess each enantiomer. In this study, fluindapyr enantiomers were baseline separated by supercritical fluid chromatography-mass spectrometry in 2 min. The limit of quantification (LOQ) of this method was 5 μg/kg. The developed method was applied to monitor the fluindapyr enantiomers in cucumber and tomato, the data showed that R- (-)-fluindapyr was preferentially degraded in tomato leaves, S -(+)-fluindapyr was preferentially degraded in cucumber leaves, and fluindapyr enantiomers had no enantioselective degradation behavior in two fruits. It is proved again that enantiomers have different enantioselective degradation behavior with the different plant species and even to different parts of the same plant. The enantioselectivity is likely to be caused by different biodegradation enzyme systems. [ABSTRACT FROM AUTHOR]

• SFC-MS/MS was initially developed for detection of mefentrifluconazole enantiomers. • Enantioselective behaviors of mefentrifluconazole were evaluated in the greenhouse vegetables system and pickling process. • S -(+)-mefentrifluconazole was preferentially degraded than R -(−)-mefentrifluconazole in pepper and pickling cucumber. • Mefentrifluconazole were removed 89.2% in cucumber, and 30.8% in pepper after cleaning and pickling. A fast, effective, and environmental-friendly method was developed for enantioseparation and analysis of mefentrifluconazole in vegetables based on supercritical fluid chromatography tandem mass spectrometry. The enantioselective behaviors of mefentrifluconazole enantiomers in tomato, cucumber, and pepper in the greenhouse, and pickled cucumber and pepper during processing were investigated. Mefentrifluconazole enantiomers could obtain baseline separation within 2 min. The average recoveries of all matrices ranged from 78.4% to 119.0%, with relative standard deviations less than 16.8% for two enantiomers. S -(+)-mefentrifluconazole was preferentially degraded in pepper, while there was no enantioselectivity in tomato and cucumber under field conditions. During processing, S -(+)-mefentrifluconazole was reduced preferentially than R -(−)-mefentrifluconazole in pickled cucumber and cucumber brine. Inversely, R -(−)-mefentrifluconazole degraded faster than S -(+)-mefentrifluconazole in pepper brine. But, no obvious enantioselectivity was observed in pickled pepper. The result of this study could contribute to a more accurate dietary risk assessment of mefentrifluconazole in vegetables and processed products. [ABSTRACT FROM AUTHOR]