Enantioselective monitoring of chiral fungicide famoxadone enantiomers in tomato, apple, and grape by chiral liquid chromatography with tandem mass spectrometry

Abstract

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.

Enantioselective fate of famoxadone during processing of apple cider and grape wine

“…Food processing will lead to the changes of pesticide residues in foods 32 . Joint Meeting On Pesticide Residues (JMPR) and Organisation for Economic Co‐operation and Development (OECD) evaluate the effect on residue levels in the various processed products by PFs 20,22 . The PFs of famoxadone racemate and enantiomers during apple cider and grape wine processing are presented in Table 4.…”

“…Optimal conditions were as follows: the cone voltage was 30 V, 372.9 ( m/z ) was selected as precursor ion, and the quantitative and qualitative ions were m/z 282.0 and 329.0 when collision energy were 20 V and 15 V, respectively. The elution order of the famoxadone enantiomers was R ‐(−)‐famoxadone and S ‐(+)‐famoxadone 22 …”

“…32 Joint Meeting On Pesticide Residues (JMPR) and Organisation for Economic Co-operation and Development (OECD) evaluate the effect on residue levels in the various processed products by PFs. 20,22 The PFs of famoxadone racemate and enantiomers during apple cider and grape wine processing are presented in Table 4. The results suggested that PFs ranged from 0.026 to 0.787 in the different stages of wine-making process, and all these were less than 1, indicating that the concentration of famoxadone racemate and enantiomers were lower in the processed commodity.…”

Chiral Fungicide Famoxadone: Stereoselective Bioactivity, Aquatic Toxicity, and Environmental Behavior in Soils

“…Famoxadone (Figure S1 of the Supporting Information), (R,S)-5-methyl-5-(4-phenoxyphenyl)-3-(phenyl amino)-2,4oxazolidinedione, is a class of oxazolidinone fungicides with good activity for Basidiomycetes, Ascomycetes, and Oomycetes. 8,9 Therefore, it can be applied to treat apple ring spot, apple spot leaf drop, grape downy mildew, tomato late blight, and tomato early blight. 10,11 Famoxadone can inhibit electron transfer in mitochondria of pathogen cells, the cessation of oxidative phosphorylation, and the death of pathogen cells as a result of the loss of the energy source.…”

“…Famoxadone (Figure S1 of the Supporting Information), ( R , S )-5-methyl-5-(4-phenoxyphenyl)-3-(phenyl amino)-2,4-oxazolidinedione, is a class of oxazolidinone fungicides with good activity for Basidiomycetes, Ascomycetes, and Oomycetes. , Therefore, it can be applied to treat apple ring spot, apple spot leaf drop, grape downy mildew, tomato late blight, and tomato early blight. , Famoxadone can inhibit electron transfer in mitochondria of pathogen cells, the cessation of oxidative phosphorylation, and the death of pathogen cells as a result of the loss of the energy source. The cytochrome bc 1 complex is an essential component in the respiratory chain, and it catalyzes electron transfer from quinol to cyt bc 1 and concomitantly transports protons across membranes. − Famoxadone is a specific Q o site bc 1 inhibitor for electron transfer in mitochondria of pathogen cells .…”