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Residual Pesticides Analysis of Botanical Ingredients Using Gas Chromatography Triple Quadrupole Mass Spectrometry

Riki Kitano1, Tairo Ogura1, Nicole Lock1, Robert Clifford1, Julie Kowalski2, Jack Cochran2, Dan Li2
1. Shimadzu Scientific Instruments, Inc. 2. Restek Corporation

Originally published by Shimadzu Corporation in collaboration with Restek Corporation.

Introduction

The use of dietary supplements is increasing in the United States. These dietary supplements are made from various dried botanicals, which may contain residual pesticides from agricultural practices, and because of that, they have to be monitored to ensure their quality and prevent exposure. The ingredients are dried which requires the standard QuEChERS methods [1] to be modified to overcome this difficulty. Gas chromatography is the best technique to separate multicomponents including coextracted interferences, and because the triple quadruple mass spectrometer (GC-MS/MS) is highly sensitive this allows analysis of trace level contamination. In this study, we analyzed over 200 compounds simultaneously using a triple quadrupole gas chromatograph mass spectrometer with the modified QuEChERS method.

Materials and Methods

Pesticides standards, internal standards, quality control standards and a QuEChERS kit were obtained from Restek:

  • GC Multiresidue Pesticide Kit (cat.# 32562)
  • QuEChERS Internal Standard Mix for GC-MS Analysis (cat.# 33267)
  • SV Internal Standard Mix (cat.# 31206)
  • Q-sep QuEChERS Extraction Kit (Original cat.# 23991 discontinued; see cat.# 25848)

The total number of targets was 232 compounds (220 pesticides, 6 internal standards, and 6 quality control standards). Ginseng, which can be purchased in any store, was used as a matrix. Using this ginseng, matrix-matched calibration standards (1 to 200 ng/mL) and fortified samples (each two 10 and 50 ng/g) were prepared. Calibration curves were generated by an internal standard method, weighted 1/C and the internal standard was PCB52.

An MRM analytical method was created using the Smart Pesticides Database (Shimadzu). This database has retention indices for all registered compounds, and retention times can be predicted by running an n-alkane sample mixture (AART: Automatic Adjustment of Retention Time). According to estimated retention times, Smart MRM creates an optimum data acquisition time program (Figure 1).

Figure 1: Data Acquisition Time Program Created by Smart MRM

Data Acquisition Time Program Created by Smart MRM

Extraction and Clean-up Procedure

  • Weigh 1.0 ± 0.05 g ground ginseng powder into 50 mL polypropylene centrifuge tube.
  • Add 10 mL HPLC-grade water and vortex the tube vigorously.
  • Add 10 mL of the ACN/IS Extraction Solvent.
  • Allow the tube to sit for 15 min.
  • Add 4 g anhydrous MgSO4 and 1 g NaCl.
  • Shake the tube vigorously on a mechanical shaker for 30 min.
  • Centrifuge the 50 mL tubes at 3000–4500 rpm × 5 min.
  • Condition the GCB/PSA (0.25 g/0.5 g) SPE columns with ~250 mg anhydrous Na2SO4 on top using 3 column volumes of acetone.
  • Insert a collection rack consisting of 15 mL disposable glass centrifuge tube on a SPE vacuum manifold.
  • Add 1.25 mL of the ACN extract.
  • Rinse with 1 mL acetone.
  • Elute with 12 mL of 3:1 v/v acetone:toluene.
  • Evaporate (50 °C) the eluent to ~100 μL gently.
  • Add 500 μL of toluene to the Blank/fortified samples, calibration standard solutions to matrix matched calibration standards.
  • Add 20 μL quality control standards (12.5 μg/mL) and ~50 mg of anhydrous MgSO4 to all samples.
  • Vortex for 5 sec.
  • Centrifuge the tubes at 3000 g × 5 min.
  • Transfer the toluene extract using a Pasteur pipette to ALS GC vials.

Result and Discussion

Matrix Matched Calibration

The chromatogram in Figure 2 shows a 10 ng/mL matrix matched calibration standard. Of the 232 compounds, 230 could be detected in ±0.1 min of estimated retention time by AART. The remaining two compounds, 1,4-Dichlorobenzene-d4 and Naphthalene-d8 of six quality control standards, had eluted before 4 min. Although retention times were shifted, they were with identified within about ±0.2 min of estimated.

Figure 2: MRM Chromatogram of 10 ng/mL Matrix Matched Calibration Standard (Internal standards and quality control standards are not displayed.)

Residual Pesticides in Botanicals by GC-MS/MS
GC_FS0568
ColumnRxi-5ms, 30 m, 0.25 mm ID, 0.25 µm (cat.# 13423)
using Rxi guard column 5 m, 0.25 mm ID (cat.# 10029)
with SilTite μ-Union connector kit (cat.# 23885)
SampleGC Multiresidue pesticide kit (cat.# 32562)
Diluent:Toluene
Conc.:10 ng/mL
Injection
Inj. Vol.:2 µL pulsed splitless
Liner:Topaz 3.5 mm ID single taper inlet liner w/wool (cat.# 23336)
Inj. Temp.:250 °C
Pulse Pressure:36 psi (248.2kPa)
Pulse Time:1.5 min
Oven
Oven Temp.:90 °C (hold 1 min) to 130 °C at 30 °C/min to 330 °C at 10 °C/min (hold 2 min)
Carrier GasHe, constant linear velocity
Linear Velocity:55 cm/sec
DetectorShimadzu GCMS TQ8040
Transfer Line Temp.:290 °C
Analyzer Type:Quadrupole
Source Temp.:230 °C
Electron Energy:70 eV
Ionization Mode:EI
InstrumentShimadzu GCMS-TQ8040
NotesMatrix-matched calibration standards were prepared in ginseng. Calibration curves were generated by the internal standard method using PCB52 as the internal standard. An MRM analytical method was created using the Shimadzu pesticides database.

Although the multiresidue pesticides kit mixes are formulated to ensure maximum long-term stability and reliability as packaged, stability may become an issue when a large number of compounds with different chemical functionalities are combined together into a single mix. This should be taken into consideration for quantitative analysis.


AcknowledgementChromatogram provided by Shimadzu. Publication 3655-11615-10ANS (C146-E334), First Edition, December 2016. Residual Pesticides Analysis of Botanical Ingredients Using Gas Chromatography Triple Quadrupole Mass Spectrometry. Riki Kitano, Tairo Ogura, Nicole Lock, Robert Clifford, Julie Kowalski, Jack Cochran, Dan Li

Calibration curves were generated from matrix matched calibration standards, then back calculation and linearity were evaluated.

Back calculation was performed by calculating the concentration of each calibration point, and if the concentration exceeds ±20% of theoretical value, the calibration point would be interpolated with the nearest two points. Over 93% of the compounds with concentration of 1 ng/mL were within ±20% of theoretical calculations and all compounds of concentration 20 to 200 ng/mL were within ±20% (Figure 3).

Figure 3: Difference Between Back Calculation and Theoretical Concentration

Difference Between Back Calculation and Theoretical Concentration

This modified QuEChERS method contains dilution steps, and samples will be diluted by quarter. To quantify 10 ng/g concentration, 2 ng/g or lower calibration point are required. Even at low concentrations, the calibration curves show good linearity (Figure 4) and all coefficients of determination (220 pesticides) were greater than 0.99.

Figure 4: Calibration Curves of Representative Six Compounds

Calibration Curves of Representative Six Compounds

Recovery of Fortified Samples

Each two 10 ng/g and 50 ng/g fortified samples were prepared (10 ng/g-1, 10 ng/g-2, 50 ng/g-1, 50 ng/g-2) and these recovery rates were evaluated from the average of three successive data points for each sample.

Of the compounds, 85% showed good recovery within the range of 70 to 120% on 10 ng/g-1 and 50 ng/g-2. As mentioned previously, fortified samples were diluted to 2.5 ng/mL and 12.5 ng/mL. Since calibration curves showed good linearity at low concentration and modified QuEChERS method suppressed interference, good recovery results were achieved. (Some compounds were not quantified correctly because the matrix for the calibration standards originally contained them. Y-intercept were lifted up and this shift might cause incorrect quantification, especially at low concentration. From the standard addition method, 16 pesticides were detected with more than 10 ng/g in matrix.)

In this study, recovery results were rechecked and combined with qualitative information, the relative ion ratio. Ion ratios between the target and reference were compared to that of the 100 ng/g standard and evaluated according to SANCO/12571/2013 [2]). This mentions that the use of relative ratio ±30% as a criterion is recommended.

Table I shows recovery and relative ion ratio for all compounds and Figure 5 shows the combination map of recovery and relative ion ratio, which was generated from this table. Of the compounds, 76% in the 10 ng/g-1 were within ±30% on relative ion ratio with good recovery of between 70 to 120%. For 50 ng/g-2, 83% of the compounds were within a ±30% relative ion ratio. And here, compounds which showed poor recovery and/or over ±30% relative ion ratio were examined.

Table I: Recovery and Relative Ion Ratio; Relative ion ratios were calculated by those of 100 ng/mL standard solution.

ID

Compound Name

Transitions

Recovery
(Average of n = 3)

Relative Ion Ratio
(Average of n = 3)

Target

CE

Reference

CE

10 ng/g-1

10 ng/g-2

50 ng/g-1

50 ng/g-2

10 ng/g-1

10 ng/g-2

50 ng/g-1

50 ng/g-2

1

2,3,5,6-Tetrachloroaniline

228.9 > 158.0

18

230.9 > 158.0

22

72.5

67.0

61.4

68.8

93.6

97.2

98.9

101.1

2

2,4'-Methoxychlor

227.1 > 121.1

16

228.1 > 122.1

16

83.0

101.1

86.5

80.2

94.7

105.0

104.6

106.7

3

2-Phenylphenol

170.1 > 141.1

24

170.1 > 115.1

28

72.7

72.3

63.2

69.0

113.1

112.9

99.1

102.1

4

3,4-Dichloroaniline

161.0 > 99.0

22

161.0 > 126.0

14

74.5

66.2

56.4

64.4

103.8

105.5

105.8

106.0

5

4,4'-Dichlorobenzophenone

139.0 > 111.0

14

139.0 > 75.0

26

77.4

83.2

73.5

73.8

97.5

104.7

102.0

100.3

6

4,4'-methoxychlor olefin

308.0 > 238.1

16

310.0 > 238.1

20

84.4

94.8

85.7

83.0

99.4

101.0

100.0

98.4

7

Acequinocyl deg.

342.2 > 188.1

14

342.2 > 160.1

22

105.3

269.8

201.1

115.2

61.2

62.8

90.7

64.0

8

Acetochlor

223.1 > 132.1

22

223.1 > 147.1

10

77.5

88.3

77.4

77.1

109.0

104.1

102.8

106.2

9

Acrinathrin

289.1 > 93.0

14

181.1 > 152.1

26

102.5

121.4

91.0

82.4

87.0

94.7

92.3

95.1

10

Alachlor

188.1 > 160.1

10

188.1 > 132.1

18

74.1

87.2

77.8

74.1

114.7

107.2

97.3

103.5

11

Aldrin

262.9 > 191.0

34

262.9 > 193.0

28

86.0

66.9

65.2

74.3

79.8

101.1

104.6

93.2

12

Allidochlor

132.1 > 56.0

8

132.1 > 49.0

24

71.8

64.5

59.0

65.9

123.7

118.4

113.4

117.2

13

Anthraquinone

208.1 > 180.1

10

208.1 > 152.1

22

0.0

126.7

47.4

48.0

97.0

83.6

90.4

94.0

14

Atrazine

200.1 > 104.1

18

200.1 > 122.1

8

77.8

94.0

83.3

78.6

105.3

110.1

92.5

100.6

15

Azinphos-ethyl

160.1 > 132.1

4

160.1 > 77.0

18

91.4

115.5

94.5

86.5

102.1

94.8

100.0

98.7

16

Azinphos-methyl

160.1 > 132.1

6

160.1 > 77.0

20

84.1

124.7

93.0

83.3

89.6

103.3

98.2

100.0

17

Benfluralin

292.1 > 264.0

8

292.1 > 160.0

22

78.4

77.0

64.5

70.7

97.7

89.1

96.8

95.3

18

BHC, alpha-

180.9 > 144.9

16

218.9 > 182.9

8

62.5

50.4

58.2

66.1

99.0

104.0

99.2

104.3

19

BHC, beta-

180.9 > 144.9

16

218.9 > 182.9

8

69.6

87.6

76.8

71.8

102.2

102.9

98.9

104.1

20

BHC, delta-

180.9 > 144.9

16

218.9 > 182.9

8

28.6

87.6

69.0

67.8

102.5

104.3

106.4

104.2

21

BHC, gamma-

180.9 > 144.9

16

218.9 > 182.9

8

64.1

73.3

62.0

69.8

94.8

93.9

103.1

102.8

22

Bifenthrin

181.1 > 166.1

12

181.1 > 179.1

12

84.6

99.2

89.3

81.4

97.0

104.4

116.7

105.9

23

Bioallethrin

123.1 > 81.1

10

136.1 > 93.1

14

81.7

100.7

83.6

71.9

463.4

563.8

200.4

228.1

24

Biphenyl

154.1 > 128.1

22

154.1 > 115.1

24

90.0

67.9

56.2

65.1

105.5

105.1

106.3

106.0

25

Bromfenvinfos-methyl

294.9 > 109.0

16

296.9 > 109.0

16

85.5

98.5

84.2

77.6

103.5

92.2

100.9

102.7

26

Bromfenvinphos

266.9 > 159.0

14

268.9 > 161.0

16

78.4

97.8

88.2

79.2

102.1

94.7

100.9

102.3

27

Bromophos

330.9 > 315.9

14

328.9 > 313.9

18

70.9

86.2

77.2

76.4

104.6

98.6

97.2

98.6

28

Bromophos-ethyl

358.9 > 302.9

16

302.9 > 284.9

18

78.0

86.9

76.5

75.8

91.9

89.6

98.5

98.4

29

Bromopropylate

340.9 > 182.9

18

340.9 > 184.9

20

85.8

104.5

94.3

85.6

101.4

100.9

101.0

99.2

30

Bupirimate

273.1 > 108.1

16

273.1 > 193.1

8

94.4

102.8

92.2

87.0

82.0

98.3

98.1

92.8

31

Captafol

79.0 > 77.0

14

79.0 > 51.0

20

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.

32

Captan

149.1 > 105.1

4

149.1 > 79.1

14

90.7

95.3

83.4

75.3

232.6

240.2

118.7

135.5

33

Carbophenothion

341.9 > 157.0

14

341.9 > 199.0

8

81.9

97.6

84.2

79.2

58.6

66.3

80.4

91.6

34

Carfentrazone-ethyl

340.1 > 312.1

14

312.1 > 151.1

24

85.3

100.6

94.0

87.3

81.5

81.8

101.9

94.7

35

Chlorbenside

125.0 > 99.0

18

127.0 > 89.0

18

80.3

83.4

73.5

71.8

86.9

93.5

96.8

99.3

36

Chlordane, cis-

374.8 > 265.9

26

372.8 > 265.9

22

76.4

84.2

76.6

77.1

94.8

99.2

105.3

101.1

37

Chlordane, trans-

374.8 > 265.9

26

372.8 > 265.9

22

76.6

77.3

75.9

72.9

96.3

106.5

103.2

102.7

38

Chlorfenapyr

247.1 > 227.0

16

247.1 > 200.0

24

84.3

114.9

87.1

85.0

51.3

71.3

112.2

98.6

39

Chlorfenson

175.0 > 111.0

12

301.9 > 175.0

8

77.0

89.1

81.4

76.4

99.5

100.6

100.5

98.0

40

Chlorfenvinphos, (E)-

323.0 > 267.0

16

267.0 > 159.0

18

110.3

114.8

74.7

72.9

270.4

484.8

103.9

99.9

41

Chlorfenvinphos, (Z)-

323.0 > 267.0

16

267.0 > 159.0

18

85.5

96.6

82.7

78.5

105.8

101.5

104.8

101.2

42

Chlorobenzilate

251.0 > 139.0

14

139.0 > 75.0

26

87.5

106.9

88.9

80.3

98.3

92.0

100.1

101.1

43

Chloroneb

206.0 > 141.0

20

193.0 > 113.0

18

65.4

59.8

59.8

68.6

111.1

110.8

107.9

105.9

44

Chlorothalonil

263.9 > 168.0

24

263.9 > 228.8

18

N.D.

N.D.

5.2

N.D.

N.D.

N.D.

82.3

N.D.

45

Chlorpropham

213.1 > 171.1

6

127.1 > 92.0

18

77.7

81.7

72.5

73.3

99.6

101.7

99.0

101.4

46

Chlorpyrifos

313.9 > 257.9

14

313.9 > 285.9

8

71.2

77.8

74.9

74.2

100.5

93.8

93.6

95.7

47

Chlorpyrifos-methyl

285.9 > 93.0

22

287.9 > 93.0

22

77.0

89.3

73.1

75.3

92.9

91.7

102.6

98.0

48

Chlorthal-dimethyl

298.9 > 220.9

24

300.9 > 222.9

26

78.8

81.9

77.3

73.7

90.7

95.7

96.1

99.9

49

Chlorthiophos-1

256.9 > 239.0

14

256.9 > 193.0

22

91.4

108.5

84.2

83.5

8.4

49.4

77.2

68.6

50

Chlorthiophos-2

324.9 > 268.9

14

268.9 > 205.0

18

76.1

96.8

84.6

80.0

73.8

79.3

95.8

101.5

51

Chlorthiophos-3

324.9 > 268.9

14

268.9 > 205.0

18

78.4

100.2

86.8

77.8

92.6

85.9

100.8

97.8

52

Chlozolinate

258.9 > 188.0

14

330.9 > 258.9

6

75.6

82.2

75.9

76.1

91.7

98.3

103.8

104.3

53

Clomazone

204.1 > 107.0

20

204.1 > 78.0

26

72.7

72.2

70.9

74.9

100.7

99.6

101.8

98.6

54

Coumaphos

362.0 > 109.0

16

362.0 > 226.0

14

90.1

110.4

98.2

89.7

84.4

84.7

94.5

94.9

55

Cycloate

154.2 > 72.0

6

215.1 > 154.2

4

69.8

66.7

61.2

69.5

89.3

89.9

93.3

94.0

56

Cyfluthrin-1

226.1 > 206.1

14

163.1 > 127.1

6

92.8

111.7

98.2

92.1

105.2

118.8

100.9

96.1

57

Cyfluthrin-2

226.1 > 206.1

14

163.1 > 127.1

6

92.5

113.1

91.9

90.2

124.6

121.5

105.1

97.6

58

Cyfluthrin-3

226.1 > 206.1

14

163.1 > 127.1

6

81.4

96.8

92.5

81.7

117.8

160.7

124.5

128.0

59

Cyfluthrin-4

226.1 > 206.1

14

163.1 > 127.1

6

76.5

95.7

106.8

88.7

167.1

159.4

121.8

126.4

60

Cyhalothrin, lambda-

208.1 > 181.1

8

197.1 > 141.0

12

88.4

108.0

92.1

85.5

99.2

113.2

99.5

96.9

61

Cypermethrin-1

163.1 > 127.1

6

163.1 > 109.1

22

96.0

113.8

94.6

89.9

108.8

93.7

117.4

111.3

62

Cypermethrin-2

163.1 > 127.1

6

163.1 > 109.1

22

89.6

119.7

98.0

88.7

99.2

113.1

94.8

100.1

63

Cypermethrin-3

163.1 > 127.1

6

163.1 > 109.1

22

75.9

124.9

103.1

96.9

126.1

114.1

96.6

104.1

64

Cypermethrin-4

163.1 > 127.1

6

163.1 > 109.1

22

76.6

100.1

84.6

81.5

115.3

119.9

124.9

120.1

65

Cyprodinil

224.1 > 197.1

22

224.1 > 131.1

14

82.0

88.9

80.0

71.2

138.1

117.5

100.5

112.6

66

DDD, o,p'-

235.0 > 165.0

24

235.0 > 199.0

16

83.6

96.0

79.8

75.3

87.0

86.6

100.1

99.1

67

DDD, p,p'-

235.0 > 165.0

24

235.0 > 199.0

16

80.2

94.6

83.6

78.2

104.4

98.8

102.6

104.3

68

DDE, o,p'-

246.0 > 176.0

30

248.0 > 176.0

28

73.7

83.1

75.7

71.7

101.7

97.9

99.0

100.3

69

DDE, p,p'-

246.0 > 176.0

30

317.9 > 248.0

24

76.9

99.7

76.2

73.5

101.1

93.8

98.8

98.3

70

DDT, o,p'-

235.0 > 165.0

24

235.0 > 199.0

16

79.0

89.1

78.0

74.3

93.9

97.6

100.1

101.2

71

DDT, p,p'-

235.0 > 165.0

24

235.0 > 199.0

16

75.2

95.1

80.7

75.8

96.8

95.0

102.9

97.7

72

Deltamethrin

252.9 > 93.0

20

252.9 > 171.9

8

83.8

109.4

92.2

85.3

99.9

99.3

102.5

99.7

73

Di-allate-1

234.1 > 150.0

20

234.1 > 192.1

14

75.3

66.5

63.3

70.7

93.8

93.0

100.9

103.3

74

Di-allate-2

234.1 > 150.0

20

234.1 > 192.1

14

72.4

65.1

63.0

70.5

88.9

107.7

100.0

94.1

75

Diazinon

304.1 > 179.1

10

304.1 > 162.1

8

76.4

70.3

69.5

74.4

62.3

80.6

97.9

86.4

76

Dichlobenil

170.9 > 100.0

24

170.9 > 136.0

14

71.2

65.3

58.2

65.4

96.5

97.4

96.5

98.2

77

Dichlofluanid

223.9 > 123.1

8

223.9 > 77.0

28

65.0

71.1

57.8

56.9

75.4

87.4

94.4

101.7

78

Dicloran

206.0 > 176.0

10

206.0 > 124.0

24

78.1

76.6

69.7

77.0

79.0

87.7

100.6

91.0

79

Dieldrin

276.9 > 241.0

8

262.9 > 193.0

34

80.2

80.3

89.0

85.0

154.2

185.9

102.7

91.4

80

Dimethachlor

197.1 > 148.1

10

199.1 > 148.1

10

78.4

90.6

77.9

76.8

99.6

89.1

100.2

101.6

81

Diphenamid

239.1 > 167.1

8

239.1 > 72.0

16

94.7

96.0

88.3

79.8

126.1

123.6

112.2

115.5

82

Diphenylamine

169.1 > 66.0

24

169.1 > 77.0

28

78.2

74.6

65.6

71.1

85.3

99.9

98.3

100.6

83

Disulfoton

186.0 > 153.0

6

186.0 > 97.0

16

71.4

66.2

64.6

78.9

142.4

124.1

107.9

85.8

84

Edifenphos

173.0 > 109.0

10

310.0 > 173.0

14

82.6

103.7

91.0

83.6

97.9

94.6

100.3

98.2

85

Endosulfan ether

240.9 > 205.9

16

238.9 > 203.9

16

62.7

64.4

67.2

69.5

126.7

95.3

104.8

101.2

86

Endosulfan sulfate

271.8 > 236.9

18

386.8 > 252.9

16

83.8

88.4

87.0

85.1

42.5

55.6

83.3

85.8

87

Endosulfan, alpha-

194.9 > 160.0

8

194.9 > 125.0

24

74.0

80.0

75.6

80.7

77.6

76.9

92.3

83.4

88

Endosulfan, beta-

194.9 > 160.0

8

194.9 > 125.0

24

83.1

99.4

81.6

81.7

102.1

67.3

93.2

100.2

89

Endrin

262.9 > 193.0

28

262.9 > 228.0

22

84.1

89.9

77.2

75.3

50.2

49.4

85.3

88.2

90

Endrin aldehyde

249.8 > 214.9

26

344.9 > 244.9

16

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.

91

Endrin ketone

316.9 > 244.9

20

314.9 > 242.9

18

73.4

91.5

84.1

88.0

108.9

95.4

107.6

101.9

92

EPN

169.1 > 140.9

8

169.1 > 77.0

22

90.3

107.4

89.2

82.3

94.3

102.9

100.2

98.8

93

Ethalfluralin

276.0 > 202.0

18

316.1 > 276.0

10

73.3

67.7

63.0

67.1

95.2

96.4

100.9

100.6

94

Ethion

230.9 > 129.0

24

230.9 > 174.9

14

81.4

97.1

84.2

77.9

118.3

108.6

101.8

102.6

95

Etofenprox

163.1 > 135.1

10

163.1 > 107.1

18

87.1

101.1

95.6

87.3

97.4

103.1

98.8

97.8

96

Etridiazole

210.9 > 182.9

10

210.9 > 139.9

22

70.0

60.1

58.0

66.9

88.2

102.0

102.0

100.4

97

Fenamiphos

303.1 > 195.1

8

288.1 > 260.1

6

88.7

104.6

99.3

87.1

120.9

106.0

96.8

100.1

98

Fenarimol

251.0 > 139.0

14

330.0 > 139.0

8

83.9

106.7

96.5

89.4

97.4

92.6

99.3

96.0

99

Fenchlorphos

284.9 > 269.9

16

286.9 > 271.9

18

80.5

81.4

71.5

74.8

89.8

83.8

99.1

97.2

100

Fenitrothion

277.0 > 260.0

6

260.0 > 125.1

12

78.0

89.3

79.3

75.8

104.9

99.2

111.4

109.6

101

Fenpropathrin

265.1 > 210.1

12

265.1 > 89.0

28

90.3

102.8

96.8

88.2

68.9

75.9

90.9

94.4

102

Fenson

141.0 > 77.0

16

267.9 > 141.0

6

78.3

88.0

77.9

74.5

91.3

92.7

100.8

96.8

103

Fenthion

278.0 > 169.0

14

278.0 > 125.0

20

80.4

81.9

78.2

76.0

93.9

96.0

102.2

104.1

104

Fenvalerate-1

225.1 > 147.1

10

419.1 > 225.1

6

82.2

100.7

94.6

88.9

95.5

92.4

103.2

99.3

105

Fenvalerate-2

225.1 > 147.1

10

419.1 > 225.1

6

75.7

106.7

93.1

86.5

73.5

70.0

86.2

89.7

106

Fipronil

366.9 > 212.9

30

368.9 > 214.9

30

92.8

113.2

99.5

82.8

93.8

96.2

88.0

96.7

107

Fluazifop-P-butyl

282.1 > 91.0

18

383.1 > 282.1

14

77.4

94.0

89.0

80.6

101.9

96.4

99.6

100.5

108

Fluchloralin

306.0 > 264.0

8

326.0 > 63.0

16

76.4

78.4

76.9

75.1

95.8

96.0

90.4

96.5

109

Flucythrinate-1

157.1 > 107.1

12

199.1 > 107.1

22

86.9

111.9

95.6

87.3

119.8

120.4

107.1

105.2

110

Flucythrinate-2

157.1 > 107.1

12

199.1 > 107.1

22

89.4

111.0

96.0

86.6

105.1

108.4

102.6

104.6

111

Fludioxonil

248.0 > 127.0

26

248.0 > 154.0

20

94.1

110.3

96.5

86.1

91.9

101.1

98.1

96.0

112

Fluquinconazole

340.0 > 298.0

20

340.0 > 313.0

14

85.2

107.0

98.9

88.9

97.7

98.5

101.4

101.1

113

Fluridone

328.1 > 259.0

24

328.1 > 127.0

24

91.5

117.7

100.3

91.4

80.1

77.3

93.4

95.7

114

Flusilazole

233.1 > 165.1

14

233.1 > 152.1

14

78.1

93.3

84.9

83.2

105.9

91.5

94.8

95.4

115

Flutolanil

173.0 > 95.0

26

281.1 > 173.0

12

84.1

108.0

93.4

84.7

104.1

101.1

100.0

99.8

116

Flutriafol

219.1 > 123.1

14

219.1 > 95.0

28

82.9

109.6

89.8

84.2

120.1

115.2

103.9

103.9

117

Fluvalinate-1, tau-

250.1 > 55.0

18

250.1 > 200.1

16

86.7

112.8

91.9

85.5

79.4

79.9

90.8

90.4

118

Fluvalinate-2, tau-

250.1 > 55.0

18

250.1 > 200.1

16

90.4

112.0

89.1

83.9

89.6

95.5

102.5

104.7

119

Folpet

259.9 > 130.0

14

261.9 > 130.0

18

65.2

82.9

72.8

67.0

97.2

89.1

99.1

98.3

120

Fonofos

246.0 > 137.1

6

246.0 > 109.1

18

76.6

74.7

65.8

71.4

106.8

97.6

102.1

101.2

121

Heptachlor

271.8 > 236.9

20

273.8 > 238.9

16

68.6

65.4

65.0

68.6

92.3

102.0

104.0

101.2

122

Heptachlor-exo-epoxide

352.8 > 262.9

14

352.8 > 316.9

10

81.1

80.4

71.8

79.1

33.7

39.0

88.6

71.5

123

Hexachlorobenzene

283.8 > 248.8

24

283.8 > 213.8

28

45.7

28.8

48.1

62.3

101.4

100.7

102.7

99.3

124

Hexazinone

171.1 > 71.0

16

171.1 > 85.0

16

93.2

112.9

96.1

88.2

105.3

101.3

104.0

105.2

125

Iodofenphos

376.9 > 361.8

22

376.9 > 331.8

32

80.0

86.8

75.8

74.2

83.8

102.3

97.3

97.1

126

Iprodione

314.0 > 245.0

12

314.0 > 56.0

22

110.5

156.0

102.0

89.9

91.0

99.9

102.2

107.0

127

Isazofos

257.0 > 162.0

8

257.0 > 119.0

18

80.0

87.4

74.4

74.7

109.5

107.1

96.0

102.6

128

Isodrin

192.9 > 157.0

20

262.9 > 192.9

28

76.4

73.7

67.4

71.2

88.2

99.0

110.1

98.6

129

Isopropalin

280.1 > 238.1

8

280.1 > 133.1

18

76.5

88.1

73.6

71.4

89.8

82.7

97.9

106.1

130

Lenacil

153.1 > 136.1

14

153.1 > 82.1

16

85.1

103.2

97.5

85.7

109.0

108.9

124.1

111.8

131

Leptophos

376.9 > 361.9

24

374.9 > 359.9

24

86.8

102.6

89.0

82.6

95.4

99.8

101.9

103.0

132

Linuron

248.0 > 61.0

16

250.0 > 61.0

16

68.3

84.7

77.7

77.9

98.3

83.1

105.8

108.6

133

Malathion

173.1 > 99.0

14

158.1 > 125.0

10

79.9

87.3

77.6

75.3

95.2

97.4

101.3

100.9

134

Metalaxyl

249.2 > 190.1

8

249.2 > 146.1

22

83.5

88.7

89.5

81.1

103.0

122.4

104.0

100.7

135

Metazachlor

209.1 > 132.1

18

211.1 > 132.1

20

83.3

93.2

83.8

80.1

97.8

100.1

101.6

104.8

136

Methacrifos

208.0 > 180.0

8

240.0 > 208.0

4

75.6

68.7

62.9

67.2

93.3

89.0

95.3

101.8

137

Methoxychlor

227.1 > 169.1

24

227.1 > 212.1

14

82.8

101.8

90.8

83.5

109.0

108.5

103.5

103.2

138

Metolachlor

238.1 > 162.1

12

238.1 > 133.1

26

77.0

89.0

77.9

75.4

104.8

96.6

101.4

102.3

139

Mevinphos-1

192.0 > 127.0

12

127.0 > 95.0

18

75.7

70.7

64.1

71.4

95.8

104.8

103.6

102.2

140

MGK 264-1

164.1 > 93.0

10

164.1 > 80.0

24

112.8

102.9

86.2

81.3

92.5

104.4

108.1

104.7

141

MGK 264-2

164.1 > 98.0

12

164.1 > 67.0

8

74.8

89.7

79.3

78.2

116.0

100.8

93.7

96.0

142

Mirex

271.8 > 236.8

18

273.8 > 238.8

18

71.4

80.4

73.6

71.2

99.9

97.3

100.7

99.6

143

Myclobutanil

179.1 > 125.0

14

179.1 > 152.0

8

83.7

104.4

90.8

84.1

122.4

127.5

112.5

108.8

144

N-(2,4-dimethylphenyl) formamide

149.1 > 106.1

16

149.1 > 121.1

6

86.6

88.5

73.0

71.4

334.2

367.6

157.5

169.6

145

Nitralin

316.1 > 274.0

8

274.0 > 169.0

12

101.1

116.0

95.4

87.2

98.7

104.0

106.2

97.4

146

Nitrofen

202.0 > 139.0

24

282.9 > 253.0

12

83.4

91.9

85.9

77.0

89.0

95.2

99.6

104.3

147

Nonachlor, cis-

406.8 > 299.9

24

406.8 > 334.9

16

80.0

91.3

79.8

77.0

59.7

48.5

84.3

87.0

148

Nonachlor, trans-

406.8 > 299.9

24

406.8 > 334.9

16

74.8

86.0

80.8

78.2

58.4

72.4

82.3

84.6

149

Norflurazon

303.0 > 145.0

22

145.0 > 95.0

18

94.7

111.0

98.7

85.0

92.7

95.4

99.2

100.8

150

Oxadiazon

258.0 > 175.0

8

302.0 > 175.0

14

78.8

88.7

84.7

76.9

95.1

101.4

100.4

103.2

151

Oxyfluorfen

361.0 > 300.0

14

361.0 > 317.0

6

101.4

106.2

90.9

80.4

91.2

97.7

101.4

102.1

152

Paclobutrazol

236.1 > 125.0

14

236.1 > 167.0

10

92.2

116.7

92.8

86.1

98.0

86.2

100.9

100.1

153

Parathion

291.1 > 137.0

6

291.1 > 81.0

24

99.8

96.8

80.7

76.0

100.1

115.2

104.9

108.1

154

Parathion-methyl

263.0 > 109.0

14

263.0 > 246.0

6

85.5

91.6

74.2

77.4

71.7

69.8

96.2

93.7

155

Pebulate

161.1 > 128.1

6

128.1 > 57.0

6

64.1

59.1

56.9

66.7

115.3

111.1

101.3

101.7

156

Penconazole

248.1 > 157.1

26

159.1 > 123.1

22

90.9

92.6

75.3

75.4

90.0

94.4

97.6

97.5

157

Pendimethalin

252.1 > 162.1

10

252.1 > 191.1

8

84.0

84.2

73.9

73.8

89.5

98.9

102.2

104.0

158

Pentachloroaniline

262.9 > 191.9

22

264.9 > 193.9

18

23.6

83.6

52.0

72.4

99.4

99.0

101.1

98.8

159

Pentachloroanisole

279.9 > 236.8

26

279.9 > 264.8

12

69.0

65.8

60.2

67.9

102.8

93.3

101.7

101.4

160

Pentachlorobenzene

249.9 > 214.9

18

249.9 > 176.9

26

59.9

27.0

47.6

62.0

104.3

113.2

108.4

104.3

161

Pentachlorobenzonitrile

274.8 > 239.8

18

272.8 > 202.9

30

69.3

65.6

63.2

68.7

90.1

88.2

96.3

95.7

162

Pentachlorothioanisole

295.8 > 262.9

14

295.8 > 245.8

30

55.8

75.7

62.7

69.7

92.4

96.3

94.9

93.5

163

Permethrine, cis-

183.1 > 153.1

14

183.1 > 168.1

14

86.6

112.1

96.8

87.5

101.7

108.3

99.5

100.2

164

Permethrine, trans-

183.1 > 153.1

14

183.1 > 168.1

14

96.0

131.5

97.0

88.4

100.4

98.3

103.6

102.4

165

Perthane

223.2 > 167.1

14

223.2 > 193.1

28

85.3

92.7

81.9

78.1

97.1

106.8

102.3

100.3

166

Phenothrin-1

183.1 > 153.1

14

183.1 > 168.1

14

N.D.

N.D.

N.D.

84.8

N.D.

N.D.

111.5

92.4

167

Phenothrin-2

183.1 > 153.1

14

183.1 > 168.1

14

100.7

113.7

95.7

86.7

101.4

112.1

105.1

100.1

168

Phorate

260.0 > 75.0

8

231.0 > 129.0

24

74.3

63.8

61.9

69.7

92.7

116.3

99.8

101.6

169

Phosalone

182.0 > 102.0

14

182.0 > 111.0

14

86.3

101.6

93.9

84.4

117.0

123.8

101.2

104.5

170

Phosmet

160.0 > 77.0

24

160.0 > 105.0

18

86.7

105.4

92.6

83.0

100.8

100.1

103.5

101.2

171

Piperonyl butoxide

176.1 > 131.1

12

176.1 > 117.1

20

84.1

112.8

92.1

85.9

104.9

118.6

102.2

102.3

172

Pirimiphos ethyl

304.1 > 168.1

12

318.1 > 166.1

12

78.1

94.3

79.1

73.8

83.5

84.4

97.4

105.8

173

Pirimiphos-methyl

290.1 > 125.0

22

290.1 > 233.1

12

80.4

88.9

78.5

76.1

93.3

92.5

101.2

99.4

174

Pretilachlor

262.1 > 202.1

10

238.1 > 162.1

10

77.0

95.2

86.0

79.7

109.6

79.5

93.4

102.5

175

Prochloraz

180.1 > 138.1

12

180.1 > 69.0

20

68.1

110.1

85.4

81.5

106.2

102.1

91.1

91.2

176

Procymidone

283.0 > 96.0

10

285.0 > 96.0

10

12.4

140.1

78.8

79.4

103.0

101.7

104.7

101.8

177

Prodiamine

321.1 > 279.1

6

321.1 > 203.1

10

86.1

94.7

81.6

78.3

88.5

88.3

93.6

99.0

178

Profenofos

338.9 > 268.9

18

336.9 > 266.9

14

87.1

93.5

90.0

85.6

107.6

107.6

93.3

91.1

179

Profluralin

318.1 > 199.1

16

318.1 > 55.0

22

66.3

64.9

65.7

74.8

105.2

95.9

97.6

91.7

180

Propachlor

176.1 > 57.0

8

176.1 > 77.0

24

74.9

76.4

67.3

71.4

114.9

106.5

103.8

102.7

181

Propanil

217.0 > 161.0

10

160.9 > 126.0

18

93.5

105.3

91.4

78.7

100.7

106.9

95.8

104.6

182

Propargite

173.1 > 135.1

16

173.1 > 107.1

24

88.0

98.7

90.8

85.5

120.0

122.8

74.1

66.1

183

Propisochlor

223.1 > 132.1

20

223.1 > 147.1

8

83.7

90.8

79.4

77.9

91.0

100.1

98.4

101.0

184

Propyzamide

172.9 > 109.0

26

172.9 > 74.0

28

83.0

91.4

77.1

76.5

98.7

100.0

108.7

106.3

185

Prothiofos

266.9 > 238.9

10

309.0 > 238.9

14

74.3

88.9

78.0

73.9

102.4

94.4

102.7

101.2

186

Pyraclofos

194.0 > 138.0

22

360.1 > 194.0

14

91.6

111.4

97.0

87.0

84.1

89.9

99.3

100.1

187

Pyrazophos

221.1 > 193.1

12

221.1 > 149.1

14

88.7

111.9

97.3

86.1

101.7

96.0

99.9

103.7

188

Pyridaben

147.1 > 117.1

22

147.1 > 132.1

14

87.5

106.4

92.5

84.1

99.2

105.1

102.0

102.5

189

Pyridaphenthion

340.0 > 199.1

8

199.1 > 92.0

16

100.2

120.0

95.0

89.3

114.1

129.2

109.5

107.5

190

Pyrimethanil

198.1 > 118.1

28

198.1 > 158.1

18

74.4

82.5

75.3

73.2

95.2

99.1

96.4

98.5

191

Pyriproxyfen

136.1 > 96.0

14

226.1 > 186.1

14

81.3

91.9

92.8

84.4

59.7

78.1

88.1

84.8

192

Quinalphos

146.1 > 118.0

10

146.1 > 91.0

24

71.7

86.6

79.6

72.9

204.6

155.7

122.4

117.8

193

Quintozene

294.8 > 236.8

16

264.8 > 236.8

10

61.7

0.0

18.5

71.1

100.1

100.7

101.5

100.3

194

Resmethrin-1

171.1 > 128.1

12

171.1 > 143.1

6

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.

N.D.

195

Resmethrin-2

171.1 > 143.1

6

171.1 > 128.1

14

85.8

96.4

85.8

78.1

86.0

97.9

95.6

100.0

196

Sulfotep

322.0 > 294.0

4

322.0 > 202.0

10

79.1

71.8

65.5

71.8

94.6

98.9

98.0

95.0

197

Sulprofos

322.0 > 156.0

8

156.0 > 108.0

28

80.7

97.3

86.0

83.2

101.1

95.9

97.3

95.1

198

Tebuconazole

250.1 > 125.1

22

250.1 > 153.1

12

76.8

82.9

68.1

71.6

112.5

96.6

98.9

98.1

199

Tebufenpyrad

333.1 > 171.1

20

333.1 > 276.1

8

87.7

105.2

96.7

84.7

97.6

97.3

94.6

95.6

200

Tecnazene

260.9 > 202.9

14

202.9 > 85.0

24

78.8

59.9

59.7

72.4

93.9

99.1

96.8

95.8

201

Tefluthrin

177.0 > 127.1

16

177.0 > 137.1

16

79.0

81.2

67.5

72.5

92.6

94.9

101.0

98.3

202

Terbacil

161.0 > 88.0

20

117.0 > 76.0

8

97.5

111.6

86.5

82.0

81.8

77.9

92.5

96.1

203

Terbufos

231.0 > 128.9

26

231.0 > 174.9

14

78.8

80.6

65.2

70.3

111.6

100.1

102.8

104.7

204

Terbuthylazine

229.1 > 173.1

6

214.1 > 71.0

16

94.9

91.0

77.6

77.1

82.6

91.6

99.7

103.3

205

Tetrachlorvinphos

328.9 > 109.0

20

330.9 > 109.0

22

87.4

102.5

87.3

81.0

96.0

93.6

99.9

96.6

206

Tetradifon

355.9 > 159.0

18

355.9 > 228.9

12

84.1

96.6

93.6

88.5

87.9

103.1

102.9

96.7

207

Tetramethrin-1

164.1 > 107.1

14

164.1 > 77.0

22

N.D.

N.D.

100.5

94.8

N.D.

N.D.

106.5

114.1

208

Tetramethrin-2

164.1 > 107.1

14

164.1 > 77.0

22

103.2

129.6

98.4

88.4

115.2

117.0

107.9

113.8

209

THPI

151.1 > 79.0

18

151.1 > 77.0

28

79.4

85.0

81.5

78.2

104.7

104.1

103.6

108.0

210

Tolclofos-methyl

264.9 > 93.0

24

264.9 > 219.9

22

72.8

78.6

72.6

73.8

98.8

100.9

102.3

103.6

211

Tolylfluanid

238.0 > 137.1

14

181.1 > 138.1

10

66.8

79.8

65.9

64.1

118.7

117.3

114.3

107.4

212

Transfluthrin

163.1 > 127.1

6

163.1 > 143.1

16

84.2

85.7

77.1

77.6

106.3

115.0

97.7

99.0

213

Triadimefon

208.1 > 111.0

22

208.1 > 127.0

14

88.4

98.2

86.7

80.5

99.5

103.9

97.9

104.7

214

Triadimenol

168.1 > 70.0

10

128.1 > 65.0

22

N.D.

N.D.

101.2

94.2

N.D.

N.D.

80.9

85.6

215

Tri-allate

268.1 > 184.0

20

270.1 > 186.0

20

80.0

75.6

68.6

74.6

102.4

85.9

94.6

98.1

216

Triazophos

257.0 > 162.0

8

257.0 > 134.0

22

89.7

112.4

94.8

86.4

95.9

80.8

90.3

88.2

217

Tricyclazole

189.0 > 161.9

12

189.0 > 135.0

18

91.5

95.7

84.5

81.8

105.9

118.7

105.2

97.3

218

Triflumizole

278.1 > 73.0

6

206.1 > 186.1

8

87.2

88.2

71.5

76.8

83.2

110.9

97.0

99.2

219

Trifluralin

306.1 > 264.1

8

306.1 > 160.1

22

79.9

73.6

64.4

72.5

92.7

100.3

100.8

101.1

220

Vinclozolin

285.0 > 212.0

12

212.0 > 172.0

16

86.3

92.8

79.9

80.7

84.3

96.4

104.2

103.3

QC-1

1,4-Dichlorobenzene-d4

150.0 > 78.0

24

115.1 > 78.0

12

QC-2

Acenaphthene-d10

164.0 > 160.0

30

164.0 > 134.0

38

QC-3

Chrysene-d12

240.0 > 236.0

30

240.0 > 212.0

24

QC-4

Naphthalene-d8

136.0 > 84.0

22

136.0 > 82.0

28

QC-5

Perylene-d12

264.0 > 263.0

34

264.0 > 262.0

24

QC-6

Phenanthrene-d10

188.0 > 160.0

24

187.0 > 159.0

18

IS-1

2,2',5-Trichlorobiphenyl

255.9 > 186.0

26

257.9 > 186.0

26

IS-2

2,4,4'-Trichlorobiphenyl

255.9 > 186.0

26

257.9 > 186.0

26

IS-3

2,2',5,5'-Tetrachlorobiphenyl

257.0 > 222.0

12

292.0 > 220.0

26

IS-4

Triphenylmethane

244.1 > 167.1

16

244.1 > 165.1

26

IS-5

Triphenylphosphate

215.1 > 168.1

16

325.1 > 169.1

20

IS-6

Tris(1,3-dichloroisopropyl)phosphate

379.0 > 159.0

12

381.0 > 159.0

12


Compounds outside the red box (Figure 5) were classified to four groups.

Figure 5: Combination Map Between Recovery and Ion Ratio (Average of n = 3 for Each Fortified Sample) Red box shows the area of 70–120% recovery and ±30% relative ion ratio.

Combination Map Between Recovery and Ion Ratio

Group A showed low recovery; this group consisted mainly of compounds which have a low boiling point. They may have been lost in the evaporation step. Group B showed high relative ion ratios and this was caused by interference from matrix. Group C showed high recovery; this group consisted of 10 ng/g fortified sample. Some of these were in matrix originally and quantified incorrectly. Others caused by their transitions which had low response and low stability. Group D showed low relative ion ratio. It was necessary to set higher response transitions. By modifying some procedures and parameters, positions of these compounds may improve.

Conclusion

This study shows that the modified QuEChERS method combined with GC-MS/MS achieved consistent pesticides monitoring in botanical ingredients.

Although dried sample could make a heavy and difficult matrix, the modified QuEChERS method, SPE column cleanup, and toluene dilution steps suppressed interference from matrix. The GC-MS/MS detected very low amounts of pesticides even though the sample was diluted. This analytical method takes only 30 minutes in total run time and covers over 200 pesticides. It provides a high throughput solution in laboratories doing this type of analysis.

References

[1] M. Anastassiades, S. J. Lehotay, D. Štajnbaher, F. J. Schenck, Fast and Easy Multiresidue Method Employing Acetonitrile Extraction/Partitioning and “Dispersive Solid-Phase Extraction” for the Determination of Pesticide Residues in Produce, J. AOAC Int., 86 (2003) 412–431
[2] European Commission, Health & Consumer Protection Directorate-General, Guidance document on analytical quality control and validation procedures for pesticide residues analysis in food and feed, SANCO/12571/2013

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