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Abstract: An ultra high‐performance liquid chromatography with tandem triple quadrupole mass spectrometry residue method was developed and validated for the quantification and identification of dinotefuran and its main metabolites 1‐methyl‐3‐(tetrahydro‐3‐furylmethyl) urea and 1‐methyl‐3‐(tetrahydro‐3‐furylmethyl) guanidine in fruit (watermelon), vegetable (cucumber), cereal (rice), animal‐derived foods (milk, egg, and pork), soil, and water. The samples were extracted with acetonitrile containing 15% v/v acetic acid and purified with dispersive solid‐phase extraction with octadecylsilane, primary secondary amine, graphitized carbon black, or zirconia‐coated silica prior to analysis. The method had an excellent linearity (R2 ≥ 0.9942, 1–500 μg/L) and satisfactory recoveries (73–102%) at five spiked levels (0.001, 0.01, 0.05, 0.5, and 2 mg/kg) with intra‐ or interday precision in the range of 0.8–9.5% and 3.0–12.8% for the three compounds in the eight matrices. The limits of quantification were 10 μg/kg for 1‐methyl‐3‐(tetrahydro‐3‐furylmethyl) guanidine and 1 μg/kg for 1‐methyl‐3‐(tetrahydro‐3‐furylmethyl) urea and dinotefuran. The applicability of the developed method was demonstrated by determining the occurrence of dinotefuran, 1‐methyl‐3‐(tetrahydro‐3‐furylmethyl) guanidine, and 1‐methyl‐3‐(tetrahydro‐3‐furylmethyl) urea in various samples from plants, animal‐derived foods, and the environment. From 80 samples, 70 contained dinotefuran (0.8–11.7 μg/kg), among which six also contained 1‐methyl‐3‐(tetrahydro‐3‐furylmethyl) urea (water and rice, 0.5–0.9 μg/kg). [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]

Trace analysis method is a reliable basis for studying the translocation and metabolism of imidacloprid used as an insecticide in wheat, and it clarifies whether biologically active metabolites including residual imidacloprid, have long‐lasting insecticidal potency against wheat aphids under seed treatment during the entire growth period. In this study, a highly sensitive analytical method was established to determine the residues of imidacloprid and its six metabolites (5‐hydroxy imidacloprid, imidacloprid olefin, imidacloprid guanidine, imidacloprid urea, 6‐chloronicotinic acid, and imidacloprid nitrosimine) in wheat–soil systems, such as in wheat leaves, wheat ears, wheat grains, roots, and soil. All the compounds were extracted using an ACN:water (8:2, v/v) mixture and purified by dispersive solid‐phase extraction. The average recoveries ranged from 74.4% to 109.5% for all matrices, with intra‐ and inter‐day variations of less than 14.9%. The limit of quantitation was in the range of 0.001–0.005 mg/kg. The method is demonstrated to be sensitive and accurate for monitoring imidacloprid and its metabolites at trace levels during the entire growth period under field conditions. [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]

Pydiflumetofen is registered in many countries and is widely used in crop production in the racemate form. However, the environmental behavior of the enantiomers has not been studied. An effective and sensitive chiral analytical method was first established for analyzing the pydiflumetofen enantiomers by supercritical fluid chromatography with tandem triple quadrupole mass spectrometry. The enantiomers could be separated and detected using the Chiralcel OD‐3 column in less than 3 min. The separation conditions were as follows: mobile phase, CO2/methanol (80:20); flow rate, 1.0 mL/min; column temperature, 30°C, auto back‐pressure regulator pressure, 2000 psi with modified quick, easy, cheap, effective, rugged, and safe sample treatment method. The average recoveries of analytes from both matrices at three spiking levels were in the range of 84.1–103.0%. The limit of quantitation for each enantiomer was 0.005 mg/kg with a baseline resolution of approximately 1.64. The method was applied to monitor the enantioselective dissipation of pydiflumetofen in grape and soil. In grapes, (−)‐pydiflumetofen was degraded more rapidly than (+)‐pydiflumetofen. In soil, (+)‐pydiflumetofen was preferentially degraded. The data provided useful references for the risk assessment and rational use of pydiflumetofen in agriculture. [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]

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]

In this study, a sensitive and effective analytical method for the extraction and detection of three herbicide residues (florasulam, fluroxypyr, and halauxifen-methyl) in wheat and soil was developed. Samples were extracted with acetonitrile/water followed by salting out, dispersive solid-phase extraction cleanup, and detection using ultra high performance liquid chromatography coupled with tandem mass spectrometry. The target analytes were detected within a 5 min runtime using an ultra high performance liquid chromatography high-strength silica trifunctional column connected to an electrospray ionization source in positive mode. The method was validated in five replicates at three fortification concentrations in each matrix. Adequate pesticide quantification and identity confirmation were attained, even at the lowest concentration levels. The method showed very good accuracy and precision. Good recoveries were observed for the three herbicides and mostly ranged between 75.8 and 114.6%, with intraday relative standard deviations <6.01% and interday relative standard deviations <4.02%. The limits of quantification ranged between 0.14 and 7.68 μg/kg for each herbicide. The method was successfully applied for the simultaneous analysis of the three herbicides in actual trial samples, and the results proved that the proposed method was effective in detecting these three herbicides. [ABSTRACT FROM AUTHOR]

A sensitive and effective method for the simultaneous determination of residues from a new fungicide, oxathiapiprolin, and its metabolites (IN-E8S72 and IN-WR791) in soil, water, and sediment, was developed using ultra high performance liquid chromatography with tandem mass spectrometry. Three compounds were extracted from water, soil, and sediment by using acetonitrile and different proportions of formic acid aqueous solution (1% v/v for water; 2% v/v for soil; and sediment), and were cleaned with octadecylsilane. The target compounds were determined within 5 min using an electrospray ionization source in the positive mode for oxathiapiprolin and in the negative mode for the two metabolites. The limits of quantification for all the three compounds were 0.1 µg/kg in water and 1 µg/kg in soil and sediment. Recovery studies were performed using three spiked levels (0.1, 1, and 10 µg/kg for water; 1, 10, and 50 µg/kg for soil and sediment). The overall average recoveries ranged from 64.8 to 112.7% with all intra- and interday relative standard deviation values below 19.4 and 19.1%, respectively. The method validation confirmed that the proposed method was convenient and reliable for determining residual oxathiapiprolin and its metabolites in soil, water, and sediments. [ABSTRACT FROM AUTHOR]