Direct Determination of Paraquat, Diquat, Mepiquat, Morpholine, and Chlormequat Pesticides Using Ion Chromatography and High Resolution Accurate Mass Spectrometry Terri Christison1, John E. Madden1, Alex Semyonov1, Jonathan Beck2, and Jeffrey S. Rohrer1. 1Thermo Fisher Scientific, 1214 Oakmead Parkway, Sunnyvale, CA 94085; 2Thermo Fisher Scientific, 355 River Oaks Parkway, San Jose, CA, USA, 95134 Instruments
Figure 1 shows the IC-HRAM spectrometry flow diagram.
Column
Chlormequat
Dionex IonPac CS17, 2 x 250 mm
MSA Gradient Separation
Flow Rate
Alternating polymer graft with carboxylic acid groups
100 µL injection Equilibrate for 4 min at 2 mM MSA, 2 to 6.4 mM (0.1–2 min), 6.4 to 30 mM (2–5 min), 30 to 60 mM (5–7 min), 60 mM (7–9 min), 10 mM (9.0–10 min) 40 mL/min, 10 min run
Eluent Source Separation Temperatures First Detection
IC-MS interface
Column: 40 C; CD Detector: 35 C, Detector compartment: 20 C Parallel Reaction Monitoring (PRM) Results
IC-MS Installation kit, acetonitrile desolvation solvent at 0.23 mL/min delivered by a second auxiliary pump
Figure 3 shows that trimethylsulfonium, morpholine, mepiquat, and chlormequat were chromatographically resolved and diquat and paraquat were resolved by HRAM spectrometry. Table 1 lists the ions of interest with the PRM conditions.
HRAM Spectrometry
0 100
183.0917
-1.6 ppm
98.097 58.066
114.1283
114.1280
-2.6 ppm
Morpholine
70.066 68.050
D8-Paraquat
88.0764
88.0763
-1.0 ppm
0 100
MS Detection
+ESI, 3.5V, HESI II, full scan, Parallel Reaction Monitoring MS/MS (PRM)
Capillary: 425 C, Ion Transfer: 260 C
Full scan
Collision Energy (V)
PRM Window (min)
Trimethylsulfonium (TMS)
C3H9S+
5.18
50
3–6
Morpholine
C4H9NO
4.84
140
3–6
Mepiquat
C7H16N+
6.31
120
3–6
C5H13ClN+
5.91
70
6–9
Table 1. xx
Sheath: 40, Aux: 5, Sweep: 1 Arb
Temperature
Formula
Retention time (min)
0 100
97.5844 96.5797
97.0832
97.0828
-4.2 ppm
185.107 171.092
186.1146
186.1157
+0.5 ppm
TMS
62.019 61.011
77.0043
77.0043
--
50–300 m/z, AGC 1e6, MIT: 100 mS, resolution: 30,000
90 80 70
8.20
NL: 1.25E7 Base Peak F: FTMS + p ESI Full ms2
[email protected] [50.0000-395.0000] MS PRM_10x_grnbns_10ugL+IS_6
Diquat, m/z 184.0990
60 50
PRM
Chlormequat
AGC 2e5, MIT: 100 mS, 30,000 resolution, fixed first mass: 50.0 m/z, NCE 10–140V, inclusions list (Table 1)
40 30
Diquat
C12H12N2+2
8.04
50
6–9
C12H14N2+2 C12H6D8N2+2
8.05
30
6–9
20 10
Paraquat Data Analysis
ISTD d8-Paraquat
8.05
50
0 100
8.12
90
6–9
80 70
Thermo Scientific™ Xcalibur™ software, Thermo Scientific™ TraceFinder™ software
Paraquat, m/z 186.1146
NL: 1.03E7 Base Peak F: FTMS + p ESI Full ms2
[email protected] [50.0000-400.0000] MS PRM_10x_grnbns_10ugL+IS_6
PRM_10x_grn-bns_7 NL: 1.52E6 FTMS + p ESI Full ms2
[email protected] [50.0000-395.0000] 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 73.0290 131.0189 15 85.0289 119.0190 101.0087 10 5 0 60 80 100 120 140 160 180 200 220 240 m/z
143.0188
40 30
90
Base Peak F: FTMS + p ESI Full ms2
[email protected]
E
97.0828
100
40
188.1220
100
SRD-10
Base Peak F: FTMS + p ESI Full
Electrolytic Eluent Suppressor
Conductivity Detector 0.31 µS
Relative Abundance
ms2
[email protected]
trap Waste
70.0658
[50.0000-110.0000] MS 50
10000ppt_mix7_1
0
100
98.0968
50
10000ppt_mix7_1
6.0
7.0
8.0
9.0
0
10.0
60
Base Peak F: FTMS + p ESI Full
157.0760
100
50
Base Peak F: FTMS + p ESI Full ms2
[email protected]
100
[50.0000-205.0000] MS
90
10000ppt_mix7_1
NL: 6.61E5
100
G
171.0913
RT: 0.00 - 10.00
Base Peak F: FTMS + p ESI Full
NL: 2.15E7 Base Peak F: FTMS + p ESI Full ms2
[email protected] [50.0000-205.0000] MS PRM_10x_pear_IS_2
70 60
[50.0000-210.0000] MS
30
10000ppt_mix7_1
20
0 NL: 2.45E7
0.0
Base Peak F: FTMS + p ESI Full
1.0
2.0
3.0
4.0
5.0 6.0 Time (min)
7.0
8.0
9.0
The Thermo Scientific™ Dionex™ SRD-10 device was added (between the Regen Out on the suppressor and the Regen In on the CR-TC trap column) and programmed to turn off the IC pump when the IC suppressor regenerant flow stops for > 5 min. This is to prevent unneutralized (unsuppressed) eluent flowing into the MS.
[50.0000-145.0000] MS 50
10000ppt_mix7_1
0 0.0
1.0
2.0
3.0
4.0
5.0
6.0
Time (min)
7.0
8.0
9.0
180
200
220 m/z
240
260
280
300
320
340
360
378.49091 380 400
10.0
A. Trimethylsulfonium, m/z 77.0426 >62.019 B. Morpholine, m/z 88.0764 >70.0658 C. Mepiquat, m/z 114.1283 >98.0968 D. Chlormequat, m/z 122.0732 E. ISTD d8-Paraquat, m/z 97.0828 F. Diquat, m/z 183.0920 >157.0760 G.Parquat, m/z 186.1157 >171.0913
183.0914
171.0913
NL: 4.44E7 Base Peak F: FTMS + p ESI Full ms2
[email protected] [50.0000-210.0000] MS PRM_10x_pear_IS_2
60 50 40
m/z 184.0990 7.03
Parquat
NL: 1.84E7 Base Peak F: FTMS + p ESI Full ms2
[email protected] [50.0000-400.0000] MS 50000ppt_mix6_1
m/z 186.1146 2
3
4
5
6 Time (min)
7
8
9
10
11
12
Fast determinations of six quaternary amine pesticides (TMS, morpholine, mepiquat, chlormequat, diquat, and paraquat) in homogenized fruit and vegetable samples were demonstrated by ICHRAM spectrometry.
4. Thermo Scientific Application Note 666, Routine analysis of polar pesticides.
6. SANTE/11813/2017. European Commission, Directorate General for Health and Food Safety, Safety of the Food Chain, Pesticides and Biocides. http://eurl-pesticides.eu (accessed April 28, 2018)
60 50 169.0758170.0836 106.0653 60
70
118.0652
144.0805 143.0728
80 90 100 110 120 m/z 130 140 150 160 170 180 190 200
PRM_10x_pear_50-4ugL_IS_1 2.40E7 100 FTMS + p ESI Full ms2
[email protected] 90 [50.0000-210.0000]
TRADEMARKS/LICENSING © 2018 Thermo Fisher Scientific Inc. All rights reserved. All trademarks are the property of Thermo Fisher Scientific and its subsidiaries. This information is not intended to encourage use of these products in any manner that might infringe the intellectual property rights of others.
185.1069
80 70 60 50 40
30
NL: 2.76E7 Base Peak F: FTMS + p ESI Full ms2
[email protected] [50.0000-395.0000] MS 50000ppt_mix6_1
185.1069
70
0 50
70
171.0913
186.1148
30
20
172.0946
20
10 0 0.0
157.0758
10
Paraquat, 90 80 m/z 186.1146
7.63
Diquat
5. Rajski, et al. Coupling Ion Chromatography to Q-Orbitrap for the Fast and Robust Analysis of Anionic Pesticides in Fruits and Vegetables, J. AOAC., 101(2), 2018.
20
100
10.0
ms2
[email protected]
Mass spectrometer
160
30
0
Relative Abundance
100
140
40
40
ms2
[email protected]
0
122.0732
120
PRM_10x_pear_50-4ugL_IS_1 1.17E7 100 FTMS + p ESI Full ms2
[email protected] 90 [50.0000-205.0000] 80
50
[50.0000-135.0000] MS 50
157.0758
Diquat, 80 m/z 184.0990
ms2
[email protected] 10000ppt_mix7_1
D
100
Figure 5. Ten-Fold Diluted, QuPPe-Extracted Pear Sample
10
Data Management
80
NL: 7.75E5
F
0
NL: 1.03E7
C
5.0
NL: 1.41E5 Base Peak F: FTMS + p ESI Full ms2
[email protected] [50.0000-145.0000] MS 50000ppt_mix6_1
m/z 122.0733
3. Thermo Scientific Application Note 661, Fast routine analysis of polar pesticides.
118.0652 144.0807 106.0653
0
NL: 1.29E6
B
4.0
2.49
Chlormequat
2. Adams, S., FERA, Ltd. The Analysis of Polar Pesticides by Ion - Exchange Chromatography Tandem Mass Spectrometry; A Tale of Two (and many more) Molecules, NACRW 2016 symposium.
Time (min)
Relative Abundance
Eluent Generator Cartridge (H+)
0
3.0
Mepiquat
1. European Commission, QuPPe Method. http://quppe.eu/ (accessed April 28, 2018)
[50.0000-120.0000] MS 50
Relative Abundance
Makeup Pump (Solvent)
10000ppt_mix7_1
2.0
NL: 1.77E8 Base Peak F: FTMS + p ESI Full ms2
[email protected] [50.0000-135.0000] MS 50000ppt_mix6_1
m/z 114.1280
REFERENCES
380
45
5
1.0
360
50
15
ms2
[email protected]
[50.0000-100.0000] MS 50
0 0.0
340
55
10
Base Peak F: FTMS + p ESI Full
320
60
20
77.0425
300
65
25
10
A
280
171.0915
80
30
100
260
186.1150
95
35
20
NL: 2.30E7
3.33
185.1071
70
50
NL: 2.52E7
50
NL: 2.01E5 Base Peak F: FTMS + p ESI Full ms2
[email protected] [50.0000-110.0000] MS 50000ppt_mix6_1
The JM0006 prototype column improved the chromatographic resolution of diquat and paraquat, but more column development is needed.
PRM_10x_grn-bns_10ugL+IS_6 NL: 9.35E6 FTMS + p ESI Full ms2
[email protected] [50.0000-400.0000] 100
85
m/z 88.0762
TMS, morpholine, mepiquat, and chlormequat pesticides were chromatographically separated, where as diquat and paraquat were resolved by accurate mass spectrometry.
171.0915 183.0915 157.0759
75
60
Figure 3. Chromatograms of ISTD and Six Cationic Pesticides Using PRM Mode
Morpholine
MSA gradient used on the prototype column JM0006
CONCLUSIONS
Figure 4. PRM Chromatograms and Spectra: Resolution of 20 µg/L Diquat from 20 µg/L Paraquat in QuPPe-Extracted Green Bean Sample
100
2.23
1
Paraquat
RT: 0.00 - 10.00
0 100
NL: 2.76E6 Base Peak F: FTMS + p ESI Full ms2
[email protected] [50.0000-100.0000] MS 50000ppt_mix6_1
m/z 77.0426
0 100
50
Table 1. Ions of Interest and PRM Conditions
Add 30 mL of cold methanol (2. In contrast, diquat-paraquat with the carbon isotopic masses within 2 m/z fully coeluted but were easily resolved in MS/MS by HRAM spectrometry. The four pesticides had good accurate mass, between