©2015 Waters Corporation 1
Enantioseparation and Trace Level Detection of Fungicides by UPC2 and Xevo TQ-S micro
Peter Hancock Marion Twohig
©2015 Waters Corporation 2
Introduction
Crop protection chemicals provide benefits in terms of an increase in crop yields however, they must also be managed responsibly in order to minimize any adverse effects
Extensive studies and trials are carried out in support of agrochemical product registration Study data are submitted to regulatory bodies, e.g. EPA, along with the registration application. Studies ensure that any risks associated with using the product are characterised and properly understood so that it can be safely applied in the field
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Chiral Pesticides
When a crop protection active ingredient (AI) contains one of more stereogenic centers the enantioselective behaviour must be studied as it is known that enantiomers can exhibit different bioactivities
Analytical methods used to evaluate the influence of
stereochemistry on the degradation dynamics, environmental fate and final residue levels help to establish a more accurate risk assessment of crop protection products
Detection sensitivity and specificity offered by tandem quad
MS/MS is advantageous for determining trace levels in complex matrices like field crops or soil
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Experimental Description
ACQUITY UPC2 and Xevo TQ-S micro are used for the trace level enantioanalysis of five triazole fungicides in wheat grain and wheat straw
DisQue extraction modified for dry commodities was performed followed by SPE using Oasis MCX
Chiral separations using the new Trefoil AMY1, 2.5 µm column
followed by MRM detection allowed concentrations of part per trillion levels to be reproducibly detected and quantified
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Triazole Fungicides
(R)-Flutriafol (S)-Flutriafol
(R)-Tebuconazole (S)-Tebuconazole
(R)-Fenbuconazole (S)-Fenbuconazole
(R)-Uniconazole (S)-Uniconazole
(R)-Diniconazole (S)-Diniconazole
* * * *
* * * *
* *
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UPC2 Conditions
Column: ACQUITY UPC2 AMY1, 3.0 x 150 mm, 2.5 µm Column temp: 40 0C ABPR: 3000 psi Flow rate: 2.0 mL/min Make up solvent: 90:10 methanol/water + 0.1% formic acid Injection volume: 4 µL Co-solvent (B): Methanol Gradient: 88% CO2 (hold 0.1 min) → 65% CO2
(hold 2.0 min) in 1.5 min
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Xevo TQ-S micro Conditions
Ionisation: ESI+ Capillary: 1.5 kV Cone voltage: 30 V Source temp: 150 °C Desolvation temp: 500 °C Desolvation gas: Nitrogen @ 1000 L/hr Collision gas: Argon @ 3.2 x 10-3 mBar Uniconazole: 292.3 → 70.0 @ 23 eV Flutriafol: 302.2 → 70.0 @ 15 eV Tebuconazole: 308.3 → 70.0 @ 20 eV Diniconazole: 326.3 → 70.0 @ 24 eV Fenbuconazole: 337.3 → 70.0 @ 18 eV
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Triazoles Enantioseparation
Fenbuconazole
Uniconazole
Tebuconazole
Flutriafol
Diniconazole 10 ng/g in
wheat grain
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Enantiomer 1 R2 = 0.9983
Enantiomer 2 R2 = 0.9985
Linear Calibration
Uniconazole 0.05 - 50 ng/mL
Wheat Straw
Compound name: Uniconazole 1Correlation coefficient: r = 0.999172, r^2 = 0.998345Calibration curve: 13622.2 * x + 305.816Response type: External Std, AreaCurve type: Linear, Origin: Exclude, Weighting: 1/x, Axis trans: None
ng/mL-0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0 32.5 35.0 37.5 40.0 42.5 45.0 47.5 50.0
Res
pons
e
-0
200000
400000
600000
ng/mL
Res
idua
l
-5.0
0.0
5.0
Compound name: Uniconazole 2Correlation coefficient: r = 0.999270, r^2 = 0.998540Calibration curve: 13765.2 * x + 328.733Response type: External Std, AreaCurve type: Linear, Origin: Exclude, Weighting: 1/x, Axis trans: None
ng/mL-0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0 32.5 35.0 37.5 40.0 42.5 45.0 47.5 50.0
Res
pons
e
-0
200000
400000
600000
ng/mL
Res
idua
l
-5.0
0.0
5.0
10.0
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Trace Level Detection Limits Xevo TQ-S micro
0.05 ng/mL level for all compounds spiked into extracted wheat grain
matrix
Fenbuconazole
Uniconazole
Tebuconazole
Flutriafol
Diniconazole
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Summary
Enantioseparation of five triazole fungicides performed in less than 3.5 minutes using Trefoil AMY1 column
Xevo TQ-S micro provided linear calibrations of the triazole fungicides in wheat grain and wheat straw at trace levels successfully enveloping regulatory concentrations
Xevo TQ-S micro provided excellent sensitivity to relevant trace levels in wheat grain matrix
Combination of Trefoil columns, ACQUITY UPC2 and Xevo TQ-S micro successfully met expectations for this application