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

Abstract

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.

Enantioseparation and dissipation of acephate and its highly toxic metabolite methamidophos in pakchoi by supercritical fluid chromatography tandem mass spectrometry

“…The retention factor (k), the selectivity factor (α), and resolution (Rs) of acephate and methamidophos enantiomers were calculated using the following Equations ( 1)-( 3) [13]:…”

“…The thermodynamic effects were evaluated on the enantioseparation of acephate and methamidophos enantiomers according to the van't Hoff equations [13] as follow:…”

“…The supercritical fluid is of high diffusivity and low viscosity, which allows high flow rate of mobile phase without any adverse effects on separation efficiency [15]. Good separation efficiency could be obtained for chiral pesticide enantioseparation under high flow rate [13]. The separation performance was evaluated under six different flow rates (1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 mL/min, Supporting information Table S3) of the mobile phase (CO 2 /ethanol = 95/5, v/v).…”

“…However, all the above approaches conduct the enantioseparation of acephate and methamidophos under long analysis time of 17.00-27.25 min [7,10,12]. SFC-MS/MS has been widely used to analyze chiral pesticide at enantiomer level with several advantages including short analysis time, high resolution, and low organic solvent consumption [13,14]. Furthermore, high sensitivity of the analytes is achieved by adding compensation solvent after separation, which is able to enhance ionization efficiency [15].…”

The effect of tandem coupling of NicoShell and TeicoShell columns in sub/supercritical fluid chromatography on enantioresolution

“…Due to the unique properties of carbon dioxide, as a major component of the mobile phase (MP), SFC has become an ideal separation technique for using multiple columns coupled in series [37]. Compared to LC, the low viscosity and high diffusivity of the MP allow performing efficient separations at a higher flow rate with a lower pressure drop [27,38,39]. In the literature, only a few reports have investigated the tandem arrangement of different chiral columns in SFC.…”