Study on Mobility, Distribution and Rapid Ion Mobility Spectrometry

Subscriber access provided by University of Colorado Boulder

Article

Study of mobility and distribution of seven pesticides in peel and pulp in cucumber, apple and cherry tomato, and detection of pesticides using surface swab capture method followed by ion mobility spectrometry Nan Zou, Chunhao Yuan, Ronghua Chen, Juan Yang, Yifan Li, Xuesheng Li, and Canping Pan J. Agric. Food Chem., Just Accepted Manuscript • DOI: 10.1021/acs.jafc.6b03084 • Publication Date (Web): 12 Dec 2016 Downloaded from http://pubs.acs.org on December 13, 2016

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Journal of Agricultural and Food Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 27

Journal of Agricultural and Food Chemistry

1

Study of mobility and distribution of seven pesticides in peel and pulp in

2

cucumber, apple and cherry tomato, and detection of pesticides using surface

3

swab capture method followed by ion mobility spectrometry

4

Nan Zou1, Chunhao Yuan1, Ronghua Chen1,2, Juan Yang1, Yifan Li1, Xuesheng Li2,

5

Canping Pan1, *

1

6

University, Beijing, 100193, People’s Republic of China

7 8

Department of Applied Chemistry, College of Science, China Agricultural

2

Institute of Pesticide & Environmental Toxicology, Guangxi University, Nanning,

9

530005, China

10

*(Author for correspondence: e-mail: [email protected]; Fax: +86 10 62733620;

11

Tel: +86 10 62731978)

1

ACS Paragon Plus Environment


12

ABSTRACT：：

13

The research explore the mobility and distribution rules of simazine, acetamiprid,

14

hexazinone, paclobutrazol, amitraz, clofentezine and boscalid in pulp and peel of

15

apple, cucumber and cherry tomato. A lab test was carried out by treating the matrices

16

with standard solution for different periods of time. The percentage sorption of

17

pesticides ranged from 0.02% to 89.34% for three matrices. The pesticides

18

distribution was also determined, and all pesticides showed the ratio values (Q)

19

between pulp and peel concentrations in three matrices lower than 0.8, which proved

20

that the highest pesticides’ content was found in the peel. In addition, a rapid and

21

simple process combining surface swab capture method and pulse glow discharge-ion

22

mobility spectrometry (PGD-IMS) detection was established for detection of

23

pesticides on matrix surfaces. In swab method, the whole matrix surface was swabbed

24

manually by swab sticks, and swab sticks were agitated in acetonitrile to release the

25

pesticides. The releasing factors of pesticides in three matrices were calculated. The

26

linearity, LOD, LOQ and matrix effect were investigated to assess the applicability of

27

swab-IMS process in practical analysis. The swab-IMS method is rapid, sensitive, and

28

quantitative, and can be achieved in the field.

29

Keywords: Pesticides, Mobility, Distribution, Peel and pulp, Surface swab, Ion

30

mobility spectrometry

2


Page 2 of 27

Page 3 of 27


31

Introduction

32

Application of pesticides in farm land is increasing rapidly all over the world to

33

increase the quality and yield of agricultural products and prolong the storage time.1

34

In spite of the obvious benefits of the use of pesticides, there are still growing concern

35

over environmental and food safety due to the presence of pesticide residues.2 Proper

36

use of pesticides can result in beneficial yield and better economic benefit, but

37

excessive use of pesticide has caused serious attention for supervisory control. In

38

addition, improper use of pesticides cause poisoning and health risk.3

39

Several conventional technologies for the detection of trace amount of pesticides, 4,5

and gas chromatography (GC),6,7 have

40

for instance liquid chromatography (LC)

41

been reported in published articles. However, these methods were limited to

42

laboratory analysis because of the requirement of long detection time, special mobile

43

phases, vacuum conditions and skilled or semi-skilled man power for operation.8

44

These analytical technologies are not able to meet the pesticide residue detection

45

requirement of rapid, on-site and real time. Hence, it’s important to develop more

46

simple and sensitive technologies to promote pesticides rapid analysis in agricultural

47

products.

48

IMS is a rapid detection technology used to identify and separate ionized

49

compounds based on their size and structure. As a screening tool and large-scale and

50

monitoring programs on site, IMS could be potentially more popular than the more

51

widely used chromatographic technique for its operation sample, rapid, portable and

52

inexpensive. IMS is not need complicated vacuum system, and it could perform under

3



53

atmospheric pressure conditions, and it could performed screening of pollutants

54

within a few seconds. IMS technology has been applied in detection of trace amount

55

of explosives,9 drugs,10,11 pharmaceuticals,12 pesticides13,14,15 and other chemical

56

contaminants.16 For PGD-IMS, ion source with pulse type glow discharge are the key

57

component. The PGD ion source realizes the controllability to pulse width and pulse

58

ion flow intensity, meanwhile it solves the problem of ions cling to the tube wall,

59

which raises the sensitivity of IMS effectively.13

60

The element affecting the pesticide migration and distribution mechanism from

61

peel to pulp may cover: the peel’s preventing property (such as epicuticular waxes);

62

the pesticides’ physico-chemical properties (such as systemic, polarity and solubility);

63

contacting time between pesticides and matrices, and so on.17 In theory, pesticides

64

with systemic and penetrating are expected to be found in the pulp, and those with

65

touch killing property are more likely to appear in the peel.18 The distribution and

66

migration behaviour of pesticides has been observed in apples19,20 and grapes.17, 21-24

67

The aim of distribution and migration study was to explore that the highest pesticides’

68

content was found in the peel or pulp. The distribution and migration study is the

69

basic research following by surface swab capture method, which would be helpful for

70

selecting suitable pesticides and matrices to establish appropriate surface capture

71

methods detection for quantitative detection of pesticides on matrices surface.

72

In this study, matrices such as cucumber, apple and cherry tomato, pesticides

73

such as amitraz, simazine, acetamiprid, hexazinone, clofentezine, paclobutrazol and

74

boscalid, were used as models to investigate the mobility and distribution rules from

4


Page 4 of 27

Page 5 of 27


75

peel to pulp by LC-MS/MS. The work was developed by analysing samples treated by

76

standard solution in lab. The percentage sorption of pesticides and the ratios between

77

pulp and peel concentrations in three matrices were calculated. Meanwhile, a simple

78

and rapid surface swab process for capture of the selected pesticides followed by

79

PGD-IMS detection was established and optimized. The releasing factor (RF),

80

linearity, LOD, LOQ and matrix effect were investigated for evaluation of the

81

swab-PGD-IMS method. The swab-PGD-IMS method was simple, fast and fieldable,

82

and could be extended to analyze pesticides on other samples like grape, pear,

83

eggplant, etc.

84

Experimental

85

Instrumentation and parameters. IMS detection conditions: In our study, an

86

IMS detector with PGD ion source (IMS-KS-100) was used, which was provided by

87

Wuhan Syscan Technology Co.Ltd. The experimental parameters for IMS analysis are

88

summarized in Table 1. The schematic diagrams of IMS device and the fused-silica

89

capillary hold device are illustrated in Figure 1. The silica capillary is used to load the

90

extracts, and it can be substituted by original at anytime.

91

LC-MS/MS analytical conditions: Determinations of 7 pesticides were carried

92

out using an Agilent 1260 series HPLC (Agilent Technologies, Inc., USA).

93

Chromatographic separations were performed with a ZORBAX SB-C18 (2.1 × 50 mm,

94

3.5 µm, Agilent) reversed-phase column at 30 °C. The injection volume was 5 µl. The

95

constant mobile phase for analysis of pesticides was acetonitrile/0.1% acetic acid

5



96

water (70:30, v/v) with flow velocity at 0.3 mL min-1. Mass spectrometry was carried

97

out using an Agilent 6460 Triple Quadrupole system provided with ESI source. The

98

nebulizing gas pressure was 35 psi. The capillary current and voltage was 9 nA and

99

4000 V, respectively. The drying gas flow rate was 8 L min-1, and the drying gas

100

temperature was 350 °C. The multiple reaction monitoring (MRM) parameters for

101

each analyte were shown in Table 2.

102

Chemicals and reagents. Pesticide standards with purity of 96~99% were

103

obtained from China Agricultural University (CAU, Beijing). A summary of CAS,

104

Kow logP, as well as the mode of action of 7 pesticides are summarized in Table 3. All

105

individual stock standard solutions (1000 mg L-1) were madeup in acetonitrile solvent

106

and reserved at -20 °C. PSA was purchased from Tianjin Bonna-Agela Technologies

107

(Tianjin, China). Acetonitrile (chromatographic grade) was purchased from Fisher

108

Chemicals (USA). Sodium chloride (NaCl), anhydrous magnesium sulfate

109

(anh.MgSO4), and anhydrous sodium sulphate (anh.Na2SO4) (analytical reagent grade)

110

were purchased from Sinopharm Chemical Reagent (Beijing, China).

111

Mobility and distribution laboratory study of pesticides. Pesticides mobility

112

and distribution were studied by soaking untreated apples, cucumber and cherry

113

tomato in aqueous solution spiked with pesticide at 0.5 mg kg-1 concentration levels.

114

The matrices were kept at 4 °C for 1, 2, 3, 5, 7, 10 and 14 days in the dark. Three

115

replicates were carried out. The pesticides mobility and distribution in the matrices

116

was calculated through two parts: peel and pulp.

117

Detection of pesticides in peel and pulp. The three matrices, spiked at certain

6


Page 6 of 27

Page 7 of 27


118

concentration level, were weighed and disposed as follows:

119

For cucumber and apple samples, pulp and peel were separated, and the weight of

120

pulp and peel were obtained. QuEChERS method was developed for quantify

121

pesticide residues in pulp and peel.

122

To extract the pesticides absorbed in matrix peel, cherry tomato samples were

123

placed in 50 mL PTFE centrifuge tubes with 5 mL of acetonitrile as extraction solvent.

124

After repeat extraction once, the two extracts were merged and dehydrated with

125

anh.Na2SO4. Then, extracts were evaporated and accommodated to 1 mL final volume

126

with acetonitrile. Finally, the extract was filtered and injected in LC-MS/MS. After

127

removal of acetonitrile, cherry tomato whole samples were crushed for pulp extraction

128

and detected pesticide residues in pulp by QuECHERs method.

129

QuECHERS method as follows: A total of 10.00 (± 0.05) g sample was weighed

130

in a 50 mL PTFE centrifuge tube containing 10 mL acetonitrile. Then the mixture was

131

agitated vigorously for 1 min on a Multi-Tube Vortexer. 1 g of NaCl and 4 g of anh.

132

MgSO4 were added for water removal, and the tube was cooled through an ice-water

133

bath. The centrifuge tube was vortexed vigorously for 1 min and then centrifuged for

134

5 min at 3800 rpm. 1 ml upper layer extract was transferred to a 2 ml centrifuge tube,

135

which containing 50 mg PSA and 150 mg anh. MgSO4. Then centrifuge tube was

136

shaken for 1 min on Vortexer and then centrifuged at 10000 rpm for 3 min. At last, 1

137

mL of the upper extracts were filtered with a 0.22 µm filter for analysis.

138

Development of the surface swab method. A surface swab process was

139

developed to capture pesticides from three matrices surface. Swab sticks with knit

7



Page 8 of 27

140

cotton head (W × L: 0.4 × 1.0 in.) were selected to swab matrices surface. The whole

141

matrix surface was swabbed for 1.5 min manually by a swab presoaked by acetonitrile

142

solvent. Whereafter, the swab was immersed in 2 mL acetonitrile and then shaken for

143

4 min on a vortexer to elution pesticides. Finally, 1 mL of the extract was filtered with

144

a 0.22 µm filter for analysis.

145

Considering that pesticides cannot be adsorbed completely in the swab step, it is

146

necessary to calculate RFs to achieve a more accurate result. In order to calculate RFs,

147

0.1 mL of 20 mg L-1 working standard mixture was dropped on the skin of three

148

matrices and dried 20 min. The same swab procedure was applied. The RFs of

149

pesticides in three matrices were calculated using Eq. (1). /×

150

RFs =

151

IMS test procedure. An aliquot of 2 µL of liquid sample was dripped onto the

152

silica capillary fiber. Then pushing the sample holder, where the fused-silica capillary

153

hold device was placed on, and the fiber was imported into the desorption chamber.

154

Meanwhile the IMS instrument began to test. Under the rapid scanning mode with 16

155

scans per second, the each operation time was 1 min, and each operation total

156

collected 960 spectra. The ion species were related to the reduced ion mobility(K0),

157

drift time and spectrum number. Peak intensity with accumulative process was carried

158

out for component concentration calculation. IMS spectra and peak intensity were

159

deal with IMS analysis software (IMS-K-reply).

160

Results and Discussion

. × /

× 100%

8


(1)

Page 9 of 27


161

Method validation. Performance characteristics of analytical methodologies of

162

matrices peel and pulp were established according to LOD, LOQ, accuracy

163

(recoveries) and precision (relative standard deviations, RSDs).

164

In our work, matrix-matched standard calibration was chosen to quantify

165

pesticides. The linearity of the detector response ranged from 10 and 2000 µg L-1 by

166

the calculation five matrix-matched standards (10, 50, 500, 1000, 2000 µg L-1). Good

167

linearity was obtained with correlation coefficient (R2) exceed 0.999 for the peel and

168

pulp of three matrices.

169

LODs and LOQs were obtained by calculation of the signal-to-noise (S/N) ratios

170

of 3 and 10 from the sample spiked lowest concentration levels, and the results were

171

shown in Table 4. The LODs and LOQs of targets ranged from 0.03 to 3 µg kg-1 and

172

0.1 to 10 µg kg-1, respectively.

173

Three spiked concentration levels (10, 100 and 500 µg kg-1) with five parallel

174

samples were developed for assessing the precision and accuracy of the proposed

175

method, and the results of method validation were shown in Table 4. Average

176

recoveries of pesticides ranged from 85.8 to 103.6% with the RSDs from 2.4 to 6.2%.

177

Study of pesticides mobility and distribution rules. The amounts of pesticides

178

present in the pulp and peel of cucumber, apple and cherry tomato were determined.

179

The percentage sorption of pesticide residue amounts in pulp relative to their spiked

180

amounts was calculated. The results for each compound in time situations were shown

181

in Table 5.

182

Previous research has suggested that percentage sorption was not depended on the

9



183

initial concentration of solutions.18 The amounts of sorbed pesticides would increase

184

by increasing the contact time. A different behaviour of different pesticides and

185

matrices was apparent. For cucumber, acetamiprid, paclobutrazol, boscalid and

186

hexazinone were the strong adsorptive pesticides with rather high sorption percentage,

187

up to 83.31~89.34%, and the sorption percentages of simazine, amitraz and

188

clofentezine were less than 37.62%. The result was consistent with their mode of

189

action, that is, acetamiprid, paclobutrazol, boscalid and hexazinone belong to systemic

190

or selective systemic pesticides, and simazine, amitraz and clofentezine belong to

191

non-systemic pesticides with contact action. For apple, all pesticides were shown

192

lower percentages (＜34.79%). Reasons for this phenomenon may be epicuticular

193

waxes in apple peel, which blocks pesticides into the pulp. For cherry tomato,

194

acetamiprid was the most sorbed pesticide with a sorption percentage up to 56.90%,

195

and the sorption percentages of others were less than 29.60%.

196

A research of pesticide permeability in matrices pulp was executed by assessing

197

concentrations ratio (Q) between matrices pulp and peel. The average Q values for all

198

pesticides and matrices are shown in Fig. 2. For cucumber, systemic or local penetrant

199

pesticides as acetamiprid, paclobutrazol and hexazinone showed Q values above 0.3,

200

and nonsystemic pesticides such as simazine, amitraz and clofentezine showed Q

201

values lower than 0.2. For apple, all pesticides showed Q values lower than 0.05. For

202

cherry tomato, acetamiprid showed maximal Q value with 0.8, and those of other

203

pesticides were lower than 0.3. As a result, the highest pesticides’ content was found

204

in the peel, independent to the characteristics of pesticide and the structure of the

10


Page 10 of 27

Page 11 of 27


205

matrices peel.

206

Reduced ion mobilities. 3-methylpyridine was selected as calibrant of IMS in this

207

work.11,13 Under the parameters shown in Table 1, the K0 of calibrant was 1.80 cm2

208

V-1 s-1. The IMS spectra of 7 pesticides are shown in Figure 3, and their K0 are

209

summarized in Table 3.

210

Validation of the swab method. In the swab method, parameters of swab time

211

and elution time were optimized to get the best swab method. The optimized

212

parameters were determined based on highest peak intensity. The results of optimized

213

parameters were 1.5 min swab time for pesticides adsorbtion and 4 min vortex time

214

for pesticides releasing. The RFs of pesticides in three matrices were calculated using

215

Eq. (1), and the results were shown in Table 6. The experiment was conducted in

216

quintuplicate. Here, RFs of pesticides mean recoveries of surface swab capture

217

method. If making recoveries close to 100%, we may need to cost large quantities of

218

different polarity of solvents with very complex swab process. Now, the RFs of the

219

current method can be stable in a certain range, and they could be used to calculate. In

220

addition, three matrices were spiked with different concentration standard pesticides

221

to validation the swab method, and RFs still were stable.

222

For assessment the applicability of the swab-IMS process, linearity, R2, LOD,

223

LOQ and matrix effect were investigated. For constructing calibration curves, the

224

compounds at the concentration levels of 0.01, 0.02, 0.05, 0.1, 0.2, 0.5 mg L-1 were

225

analyzed by IMS, and the results were listed in Table 6. Good linearity was acquired

226

with R2 ranged from 0.9859 to 0.9998. And the LODs and LOQs were found to be 1-3

11



227

µg kg-1 and 3-10 µg kg-1, respectively.

228

The occurrence of matrix effect (ME) is perceived as a signal restrain or intensity

229

effected by matrix components. If the value of matrix/solvent slope ratio ranged from

230

0.9 to 1.1, the ME could not be considered, but not the opposite.6 The ratio value of

231

cucumber and cherry tomato matrices ranged from 0.95 to 1.04, which indicated that

232

the ME could be negligible, and standard solution could be generated to quantify

233

pesticides. However, the ratio value of apple matrices ranged from 0.84 to 0.92, which

234

illustrated that the ME of apple matrices couldn’t be ignored, so matrix-matched

235

standard was needed used for quantitative results.

236

Real Samples Analysis. The developed methods were applied in practical

237

analysis of pesticide residues in cucumber, apple and cherry tomato samples surface,

238

which collected from local supermarkets and markets in Beijing. The results were that,

239

of the 30 tested samples (10 for each matrix), 7 samples were found to contain studied

240

pesticides. One apple surface were found to contain acetamiprid with 53 µg kg-1 and

241

boscalid with 157 µg kg-1; two apple surface were found to contain paclobutrazol with

242

values ranged from 68 to 372 µg kg-1; three cucumber surface were found to contain

243

paclobutrazol with values ranged from 38 to 511 µg kg-1; one cherry tomato surface

244

were found to contain paclobutrazol with 289 µg kg-1 and boscalid with 102 µg kg-1.

245

A simple and rapid pretreatment method was established for determination of

246

simazine, acetamiprid, hexazinone, paclobutrazol, amitraz, clofentezine and boscalid

247

in pulp and peel of apple, cucumber and cherry tomato, followed by LC-MS/MS

248

detection. The mobility and distribution mechanism of the selected pesticides in peel

12


Page 12 of 27

Page 13 of 27


249

and pulp were studied by treating the matrices with standard solution in lab. The

250

amounts of sorbed pesticides in pulp increased by increasing the contact time.

251

Penetration into the matrices pulp was found for all pesticides. The highest pesticides’

252

content was observed in the peel for all pesticides and all matrices. Whereafter, a

253

surface swab capture followed by PGD-IMS was established and optimized for

254

quantification of the selected pesticides on matrices surfaces. The RFs of pesticides in

255

three matrices were calculated. The surface swab procedure is rapid, simple, sensitive,

256

and it and can be achieved in the field. Further research will focus on application the

257

swab-IMS method for pesticides analysis on other agricultural produces.

258

Acknowledgments

259

This work was supported by National Key Research and Development Program of

260

China (2016YFD0200206). We are grateful for the Guangxi Special Invited Scientist

261

(2013) program in Agric-Environment and Agro-products Safety.

13



262

References

263

(1) Ticha, J.; Hajslova, J.; Jech, M.; Honzicek, J.; Lacina, O.; Kohoutkova, J.; Kocourek, V.;

264

Lansky, M.; Kloutvorova, J.; Falta, V., Changes of pesticide residues in apples during cold storage.

265

Food Control 2008, 19, 247-256.

266

(2) Walorczyk, S.; Drożdżyński, D.; Kowalska, J.; Remlein-Starosta, D.; Ziółkowski, A.;

267

Przewoźniak, M.; Gnusowski, B., Pesticide residues determination in Polish organic crops in

268

2007-2010 applying gas chromatography-tandem quadrupole mass spectrometry. Food chem.

269

2013, 139, 482-487.

270

(3) Bajwa, U.; Sandhu, K. S., Effect of handling and processing on pesticide residues in food-a

271

review. J. Food Sci. Tech. 2014, 51, 201-220.

272

(4) Qin, Y.; Zhao, P.; Fan, S.; Han, Y.; Li, Y.; Zou, N.; Song, S.; Zhang, Y.; Li, F.; Li, X., The

273

comparison of dispersive solid phase extraction and multi-plug filtration cleanup method based on

274

multi-walled carbon nanotubes for pesticides multi-residue analysis by liquid chromatography

275

tandem mass spectrometry. J. Chromatogr. A, 2015, 1385, 1-11.

276

(5) Zhao, P.; Fan, S.; Yu, C.; Zhang, J.; Pan, C., Multiplug filtration clean‐up with multiwalled

277

carbon nanotubes in the analysis of pesticide residues using LC–ESI‐MS/MS. J. Sep. Sci. 2013,

278

36, 3379-3386.

279

(6) Zou, N.; Han, Y.; Li, Y.; Qin, Y.; Gu, K.; Zhang, J.; Pan, C.; Li, X., Multiresidue method for

280

determination of 183 pesticide residues in leeks by rapid multiplug filtration cleanup and gas

281

chromatography-tandem mass spectrometry. J. Agric. Food Chem. 2016, 64, 6061-6070.

282

(7) Zhao, P.; Huang, B.; Li, Y.; Han, Y.; Zou, N.; Gu, K.; Li, X.; Pan, C., Rapid Multiplug

14


Page 14 of 27

Page 15 of 27


283

Filtration Cleanup with Multiple-Walled Carbon Nanotubes and Gas Chromatography–

284

Triple-Quadruple Mass Spectrometry Detection for 186 Pesticide Residues in Tomato and Tomato

285

Products. J. Agric. Food Chem. 2014, 62, 3710-3725.

286

(8) Dhakal, S.; Li, Y.; Peng, Y.; Chao, K.; Qin, J.; Guo, L., Prototype instrument development for

287

non-destructive detection of pesticide residue in apple surface using Raman technology. J. Food

288

Eng. 2014, 123, 94-103.

289

(9) Mäkinen, M. A.; Anttalainen, O. A.; Sillanpää, M. E., Ion mobility spectrometry and its

290

applications in detection of chemical warfare agents. Anal. Chem. 2010, 82, 9594-9600.

291

(10) Midey, A. J.; Patel, A.; Moraff, C.; Krueger, C. A.; Wu, C., Improved detection of drugs of

292

abuse using high-performance ion mobility spectrometry with electrospray ionization

293

(ESI-HPIMS) for urine matrices. Talanta, 2013, 116, 77-83.

294

(11) Zou, N.; Chen, R.; Qin, Y.; Song, S.; Tang, X.; Pan, C., Comparison of pulse glow

295

discharge-ion mobility spectrometry and liquid chromatography with tandem mass spectrometry

296

based on multiplug filtration cleanup for the analysis of tricaine mesylate residues in fish and

297

water. J. Sep. Sci. 2016, 39, 3638–3646.

298

(12) Strege, M. A.; Kozerski, J.; Juarbe, N.; Mahoney, P., At-line quantitative ion mobility

299

spectrometry for direct analysis of swabs for pharmaceutical manufacturing equipment cleaning

300

verification. Anal. Chem. 2008, 80, 3040-3044.

301

(13) Zou, N.; Gu, K.; Liu, S.; Hou, Y.; Zhang, J.; Xu, X.; Li, X.; Pan, C., Rapid analysis of

302

pesticide residues in drinking water samples by dispersive solid-phase extraction based on

303

multiwalled carbon nanotubes and pulse glow discharge ion source ion mobility spectrometry. J.

304

Sep. Sci. 2016, 39, 1202-1212.

15



305

(14) Jafari, M. T.; Saraji, M.; Sherafatmand, H., Polypyrrole/montmorillonite nanocomposite as a

306

new solid phase microextraction fiber combined with gas chromatography–corona discharge ion

307

mobility spectrometry for the simultaneous determination of diazinon and fenthion

308

organophosphorus pesticides. Anal. Chim. Acta 2014, 814, 69-78.

309

(15) Zou, N.; Yuan, C.; Liu, S.; Han, Y.; Li, Y.; Zhang, J.; Xu, X.; Li, X.; Pan, C., Coupling of

310

multi-walled carbon nanotubes/polydimethylsiloxane coated stir bar sorptive extraction with pulse

311

glow discharge-ion mobility spectrometry for analysis of triazine herbicides in water and soil

312

samples. J. Chromatogr. A, 2016, 1457, 14-21.

313

(16) Camara, M.; Gharbi, N.; Lenouvel, A.; Behr, M.; Guignard, C.; Orlewski, P.; Evers, D.,

314

Detection and quantification of natural contaminants of wine by gas chromatography–differential

315

ion mobility spectrometry (GC-DMS). J. Agric. Food Chem. 2013, 61, 1036-1043.

316

(17) Xu, X.-m.; Yu, S.; Li, R.; Fan, J.; Chen, S.-h.; Shen, H.-t.; Han, J.-l.; Huang, B.-f.; Ren, Y.-p.,

317

Distribution and migration study of pesticides between peel and pulp in grape by online gel

318

permeation chromatography–gas chromatography/mass spectrometry. Food Chem. 2012, 135,

319

161-169.

320

(18) Lagunas-Allué, L.; Sanz-Asensio, J.; Martínez-Soria, M., Mobility and distribution of eight

321

fungicides in surface, skin and pulp in grapes. An application to pyraclostrobin and boscalid. Food

322

Control 2015, 51, 85-93.

323

(19) Clavijo, M. P.; Medina, M. P.; Asensio, J. S.; Bernal, J. G., Decay study of pesticide residues

324

in apple samples. J. Chromatogr. A 1996, 740, 146-150.

325

(20) Sanz-Asensio, J.; Martinez-Prado, A.; Plaza-Medina, M.; Martinez-Soria, M.; Pérez-Clavijo,

326

M., Behaviour of acephate and its metabolite methamidophos in apple samples. Chromatographia

16


Page 16 of 27

Page 17 of 27


327

1999, 49, 155-160.

328

(21) Cabras, P.; Angioni, A.; Garau, V. L.; Pirisi, F. M.; Cabitza, F.; Pala, M.; Farris, G. A., Fate of

329

quinoxyfen residues in grapes, wine, and their processing products. Journal of Agricultural and

330

Food Chem. 2000, 48, 6128-6131.

331

(22) Cabras, P.; Angioni, A., Pesticide residues in grapes, wine, and their processing products. J.

332

Agric. Food Chem. 2000, 48, 967-973.

333

(23) Teixeira, M. J.; Aguiar, A.; Afonso, C. M.; Alves, A.; Bastos, M. M., Comparison of

334

pesticides levels in grape skin and in the whole grape by a new liquid chromatographic

335

multiresidue methodology. Anal. Chim. Acta, 2004, 513, 333-340.

336

(24) Vaquero-Fernández, L.; Sanz-Asensio, J.; López-Alonso, M.; Martínez-Soria, M.-T., Fate and

337

distribution of pyrimethanil, metalaxyl, dichlofluanid and penconazol fungicides from treated

338

grapes intended for winemaking. Food Addit. Contam. 2009, 26, 164-171.

17



354

Figure captions

355

Figure 1. Schematic diagram of the silica ﬁber hold device and PGD-IMS device

356

(Original drawing from Zou et al. [11]).

357

Figure 2. Calculated pulp/peel concentration ratios (Q) for the target pesticides in

358

three matrices during different times.

359

Figure 3. Spectra of pesticide mixtures (at the concentration of 0.02 mg L-1): 1.

360

Amitraz, 2. Simazine, 3. Acetamiprid, 4. Hexazinone, 5. Clofentezine, 6.

361

Paclobutrazol, 7 Boscalid.

18


Page 18 of 27

Page 19 of 27


Table 1. IMS operation parameters. Parameters

Setting -1

Drift field (V cm )

300

Drift gas

Air -1

Drift gas flow (mL min )

1000

Carrier gas

Air -1

Carrier gas flow (mL min )

300

Drift tube temperature (°C)

60

Inlet temperature (°C)

180

Drift tube length (cm)

15

Discharge time (µs)

676

Ion accumulate time（µs）

728

Ion gate opening time(µs)

1534

Sampling frequency(scans/s)

16

Table 2. Different MS characteristics for the identiﬁcation and quantitation of 7 pesticides using LC-MS/MS. Pesticides

RT(min)

Simazine

0.91

Fragmentor voltage(V) 125

Parent ions 202.2

Quantifying

Qualifying

Collision

ions

ions

energy (V)

124.2

104.1

15;25

Acetamiprid

0.81

100

223.0

125.9

56

15;12

Hexazinone

0.87

100

253.1

171.1

71.1

10;30

Paclobutrazol

1.00

120

294.0

70.0

125

20;25

Amitraz

2.47

100

294.2

163.1

122.2

10;30

Clofentezine

1.43

100

303.0

138.0

102

15;40

Boscalid

1.08

150

343.0

306.8

272

15;25

19



Table 3. CAS numbers, Kow logP, K0, as well as the mode of action of selected pesticides. Pesticides

CAS

Kow logP

K0

Mode of action Selective systemic herbicide, absorbed principally through

Simazine

122–34–9

2.1

1.54±0.015

the roots, but also through the foliage, with translocation acropetally in the xylem, accumulating in the apical meristems and leaves.

Acetamiprid

135410–20–7

0.8

1.46±0.015

Hexazinone

51235–04–2

1.2

1.38±0.015

Paclobutrazol

76738–62–0

3.2

1.30±0.015

Systemic insecticide with translaminar activity and with contact and stomach action.

Non-selective, primarily contact herbicide, absorbed by the leaves and roots, with translocation acropetally.

Plant growth regulator taken up into the xylem through the leaves, stems or roots, and translocated to growing sub-apical meristems. Amitraz

33089–61–1

5.5

1.60±0.015

Clofentezine

74115–24–5

4.1

1.35±0.015

Non-systemic, with contact and respiratory action. Specific acaricide with contact action, and long residual activity. Inhibits embryo development. Foliar fungicide, with translaminar and acropetal

Boscalid

188425–85–6

2.96

1.25±0.015

movement within the plant leaf, providing preventive and, in some cases, curative action.

20


Page 20 of 27

Page 21 of 27


Table 4. Validation parameters of the analytical methodologies by LC-MS/MS (n=5; Unit of spiked level, LOD and LOQ was µg kg-1). Peel Matrices

Cucumber

Apple

Cherry tomato

Pesticides

Pulp

Recovery % (RSD %)

LOD

500

100

10

Simazine

92.5 (3.5)

95.2 (3.3)

95.4 (4.6)

0.7

Acetamiprid

98.1 (5.0)

99.4 (3.8)

96.1 (3.1)

3

Recovery % (RSD %)

LOQ

LOD

LOQ

90.4 (3.3)

0.7

2

92.3 (5.0)

98.1 (3.7)

3

10

500

100

10

2

89.4 (5.2)

92.6 (4.3)

10

98.5 (4.5)

Hexazinone

93.7 (4.4)

94.8 (2.4)

99.5 (2.8)

1.6

6

93.8 (5.3)

100.5 (6.2)

94.8 (2.4)

1.7

5

Paclobutrazol

90.5 (2.7)

97.2 (2.3)

89.4 (5.2)

1.6

5

99.5 (2.8)

89.4 (5.2)

97.2 (2.3)

1.7

5

Amitraz

95.2 (3.3)

99.5 (2.8)

98.5 (4.5)

0.1

0.3

89.4 (5.2)

98.5 (4.5)

93.3 (6.2)

0.1

0.3

Clofentezine

99.4 (3.8)

89.4 (5.2)

100.5 (3.0)

3

10

98.4 (4.1)

89.2 (3.7)

96.9 (5.1)

3

10

Boscalid

98.5 (4.1)

98.5 (4.5)

90.2 (3.9)

3

10

96.1 (3.1)

87.9 (2.4)

89.2 (3.7)

3

10

Simazine

100.3 (2.6)

96.1 (3.5)

85.8 (4.6)

1

3

99.5 (2.8)

90.2 (3.6)

87.9 (2.4)

0.7

2

Acetamiprid

94.8 (2.9)

99.5 (2.8)

99.1 (5.8)

3

10

89.4 (5.2)

97.2 (2.3)

100.7 (5.1)

3

10

Hexazinone

93.8 (5.9)

89.4 (5.0)

93.8 (5.9)

0.2

0.6

98.5 (4.5)

99.5 (2.8)

103.6 (4.6)

0.2

0.5

Paclobutrazol

99.5 (2.8)

97.2 (2.3)

94.8 (4.0)

0.2

0.5

89.2 (3.7)

89.4 (5.2)

98.2 (4.4)

0.2

0.5

Amitraz

89.4 (5.2)

90.5 (2.7)

92.0 (5.5)

0.1

0.3

87.9 (2.4)

98.5 (4.2)

104.7 (4.1)

0.07

0.2

Clofentezine

98.5 (4.5)

95.2 (3.3)

94.6 (5.7)

2

7

100.7 (5.1)

92.0 (5.5)

95.5 (3.8)

1.7

5

Boscalid

87.9 (2.1)

98.4 (4.1)

96.2 (3.1)

2

7

103.6 (4.6)

94.6 (5.0)

97.5 (3.1)

1.7

5

Simazine

100.7 (5.1)

98.1 (3.7)

99.7 (2.4)

0.2

0.5

89.4 (5.2)

93.3 (6.2)

92.6 (4.3)

1

3

Acetamiprid

97.2 (2.3)

94.8 (2.7)

98.4 (4.1)

0.3

1

88.7 (3.3)

98.5 (4.5)

92.3 (5.0)

3

10

Hexazinone

93.3 (6.2)

100.5 (6.2)

88.7 (3.3)

0.03

0.1

90.4 (2.9)

89.2 (3.7)

100.5 (6.2)

0.3

0.8

Paclobutrazol

98.5 (4.5)

94.6 (3.6)

90.4 (2.9)

0.1

0.3

98.0 (2.0)

87.9 (2.4)

94.6 (3.6)

0.3

0.8

Amitraz

100.5 (3.0)

89.4 (5.2)

98.0 (2.0)

0.03

0.1

95.2 (3.3)

90.5 (2.4)

95.9 (2.2)

0.1

0.3

Clofentezine

95.5 (3.8)

98.5 (4.0)

94.8 (5.4)

0.3

1

98.4 (4.1)

95.2 (3.3)

96.1 (4.7)

1.6

5

Boscalid

97.5 (3.1)

87.9 (2.4)

96.1 (4.2)

0.3

1

98.1 (3.7)

99.4 (3.8)

94.3 (4.2)

1.6

5

21



Page 22 of 27

Table 5. Pesticides sorption percentage in three matrices during different times. Cucumber Pesticides

Days

Sorption percentage (%)

Simazine

Acetamiprid

Hexazinone

Paclobutrazol

Amitraz

Apple Sorption

RSD

percentage

(%)

(%)

Cherry tomato RSD (%)

Sorption percentage (%)

RSD (%)

1

17.48

14.94

7.61

14.90

3.64

7.80

2

19.99

18.63

9.75

16.21

6.59

13.78

3

24.19

15.57

12.29

11.47

5.33

13.68

5

37.62

12.90

20.00

16.01

4.51

10.32

7

35.93

14.24

16.19

9.28

3.89

13.84

10

30.29

7.17

18.89

15.10

3.86

13.39

14

29.23

10.51

16.22

10.25

3.05

11.57

1

38.69

9.76

10.77

17.13

11.10

9.02

2

75.52

6.63

14.06

15.25

30.83

10.74

3

81.21

18.96

21.45

10.11

49.97

14.27

5

89.34

10.84

22.24

17.03

54.10

11.89

7

79.85

19.59

22.72

14.19

56.90

13.30

10

75.38

10.78

32.17

12.48

48.83

14.25

14

70.14

13.47

34.79

11.11

37.50

13.39

1

41.74

13.26

7.31

11.26

10.43

10.04

2

68.36

9.80

9.56

15.28

23.04

13.21

3

75.76

11.14

8.38

16.11

20.33

10.72

5

83.31

14.77

17.77

13.72

29.60

11.53

7

80.35

16.97

19.39

12.91

12.04

16.29

10

80.51

15.34

27.72

10.56

10.86

14.40

14

78.29

12.57

30.33

18.23

8.92

13.61

1

39.44

14.68

4.53

12.70

3.25

11.28

2

62.06

11.51

4.77

18.25

8.19

10.52

3

78.02

16.76

4.78

15.43

10.47

7.93

5

83.81

16.81

9.19

10.81

14.72

13.24

7

86.31

23.46

11.18

20.04

16.52

12.52

10

78.72

15.12

15.50

16.42

16.22

10.08

14

75.10

11.03

18.29

11.37

7.87

11.73

1

0.43

8.51

0.06

15.29

0.07

8.35

2

0.38

13.17

0.10

16.31

0.12

10.54

3

0.39

15.20

0.13

15.85

0.27

13.26

5

0.66

13.04

0.11

10.92

0.30

11.93

7

0.37

10.69

0.05

8.89

0.21

10.76

10

0.33

12.16

0.02

11.48

0.21

12.34

14

0.32

15.29

0.02

14.21

0.21

11.14

22


Page 23 of 27


Clofentezine

Boscalid

1

5.16

14.66

1.06

9.25

1.20

12.90

2

8.27

10.42

4.08

14.88

1.88

10.78

3

8.02

17.68

3.06

12.09

2.68

15.29

5

12.02

13.37

6.94

11.68

3.49

15.80

7

8.23

21.63

10.71

17.02

3.35

16.24

10

5.54

10.35

12.37

11.34

3.00

14.02

14

5.01

13.33

17.26

10.48

1.76

13.29

1

41.32

17.15

5.96

15.09

0.28

16.28

2

55.71

17.92

5.91

11.39

1.92

13.79

3

69.43

18.79

6.86

14.34

2.71

14.02

5

86.61

16.68

6.69

15.91

2.58

11.39

7

70.01

20.21

6.05

10.03

2.28

16.37

10

52.12

7.87

5.06

11.62

1.73

15.99

14

47.48

14.06

4.23

13.94

0.52

15.24

23



Page 24 of 27

Table 6. Validation parameters of the analytical methodologies by PGD-IMS (The unit of LOD and LOQ was µg kg-1). Cucumber Pesticides

Solvent linearity

2

Apple

Linearity

R

LOD

LOQ

ME

RF(%)

y = 5578x + 174.39

y = 5623.2x + 162.0

0.9867

2

5

1.01

Acetamiprid

y = 5120.5x + 203.16

y = 5098.1x + 218.4

0.9935

1

3

Hexazinone

y = 2379.4x + 83.691

y = 2301.4x +79.23

0.9864

3

8

Paclobutrazol

y = 4795.3x + 82.519

y = 4669.1x + 103.7

0.9998

3

Simazine

2

Cherry tomato Linearity

R2

LOD

LOQ

ME

RF(%)

58.3

y = 5429.1x + 220.4

0.9957

2

5

0.97

73.5

0.92

56.8

y = 5079.4x + 182.4

0.9869

1

3

0.99

70.5

0.84

62.4

y = 2289.6x + 170.3

0.9959

3

8

0.96

64.2

0.86

55.9

y = 4703.7x + 111.3

0.9932

3

8

0.98

68.9

Linearity

R

LOD

LOQ

ME

RF(%)

59.1

y = 5141.4x + 69.3

0.9861

2

5

0.92

1.00

70.3

y = 4725.6x + 224.5

0.9948

1

3

0.97

66.4

y = 2005.7x +148.0

0.9952

2

6

8

0.97

57.6

y = 4106.8x + 203.1

0.9873

2

6

Amitraz

y = 4983.8x + 135.71

y = 4881.6x + 206.4

0.9869

2

6

0.98

64.7

y = 4523.8x + 142.7

0.9971

2

5

0.91

66.8

y = 4892.5x + 104.6

0.9958

2

6

0.98

71.6

Clofentezine

y = 3948.2x + 121.43

y = 3883.2x + 287.6

0.9925

3

8

0.98

67.2

y = 3489.2x + 168.4

0.9859

2

6

0.88

68.2

y = 3845.6x + 200.1

0.9867

3

8

0.97

74.2

Boscalid

y = 2032.6x + 53.547

y = 2110.7x + 104.0

0.9955

3

10

1.04

65.0

y =1780.5x + 200.6

0.9976

3

10

0.88

58.1

y = 1938.7x + 168.4

0.9986

3

10

0.95

77.5

24


Page 25 of 27


Figure 1

25



Figure 2

Figure 3

26


Page 26 of 27

Page 27 of 27


Graphic for tables of contents：

27


Study on Mobility, Distribution and Rapid Ion Mobility Spectrometry

Recommend Documents