Enantioselective separation and dissipation of pydiflumetofen enantiomers in grape and soil by supercritical fluid chromatography–tandem mass spectrometry

Abstract

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, CO 2 /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.

Enantioseparation and dissipation monitoring of oxathiapiprolin in grape using supercritical fluid chromatography tandem mass spectrometry

“…Other than CSP and mobile phase, the different proportion of the organic modifier is another factor that may affect the enantioseparation. For example, resolution of pydiflumetofen enantiomers decreased with the increase of organic modifier proportion (MeOH) [30]. In this study, as the proportion of the 0.2% FA−5 mmol/L NH 4 OAc MeOH increased from 15 to 30%, the retention time (RT) of oxathiapiprolin enantiomers was shortened from 8.32 to 3.00 min and the Rs was decreased from 2.00 to 1.51 (Figure 2C(1–4)).…”

“…Wu et al. [30] monitored the enantioselective dissipation of pydiflumetofen in grape and found (+)‐pydiflumetofen was preferentially enrichment. Enzyme system of plant is considered to be an important factor for enantioselective metabolism of chiral compounds [41].…”

Enantioselective residue analysis of oxathiapiprolin and its metabolite in tea and other crops by ultra‐high performance liquid chromatography–tandem mass spectrometry

“…Furthermore, oxathiapiprolin has one asymmetric carbon center and consists of two enantiomers, as shown in Figure 1; at present, it is not clear which enantiomer is the active one. Although, there have been many reports on the analysis of chiral pesticide residues [4,5,[33][34][35][36][37], there have been no reports on the differences between enan-tiomers during residual analysis or studies of dissipation behavior, or on the enantioselective analysis for oxathiapiprolin residues in different samples. Thus, it is critical to consider the behaviors carefully and to establish a method for residue analysis of oxathiapiprolin enantiomers.…”

Evaluation of exploitive potential for higher bioactivity and lower residue risk enantiomer of chiral fungicide pydiflumetofen

“…Previous studies have confirmed the absolute configuration of the pydiflumetofen enantiomers, and found stereoselective dissipation in pakchoi, grape, and soil under field conditions. 22,23 Hence, studying the stereoselective bioactivity and its molecular mechanisms of enantiomers will gain a better understanding of plant diseases control. Studying the stereoselective degradation of chiral fungicides in more plants will provide a more comprehensive risk assessment.…”