A Simple Method for Quantifying Polycarbonate ... - ACS Publications

Subscriber access provided by LAURENTIAN UNIV

Letter

A Simple Method to Quantify PC and PET Microplastics in the Environmental Samples by LC-MS/MS Lei Wang, Junjie Zhang, Shaogang Hou, and Hongwen Sun Environ. Sci. Technol. Lett., Just Accepted Manuscript • DOI: 10.1021/acs.estlett.7b00454 • Publication Date (Web): 02 Nov 2017 Downloaded from http://pubs.acs.org on November 4, 2017

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.

Environmental Science & Technology Letters 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 21

Environmental Science & Technology Letters

1

A Simple Method to Quantify PC and PET Microplastics in the

2

Environmental Samples by LC-MS/MS

3 4

Lei Wang*, Junjie Zhang, Shaogang Hou, and Hongwen Sun

5 6

Ministry of Education Key Laboratory of Pollution Processes and Environmental

7

Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control,

8

College of Environmental Science and Engineering, Nankai University, Tianjin

9

300350, China

10

*

11

Nankai University

12

#38 Tongyan Road

13

Tianjin, China 300071

14

Phone: +86-22-2350-4262

15

Fax: +86-22-2350-8807

16

E-mail:[email protected]

17

For submission to: Environmental Science & Technology Letters

Corresponding author: L. Wang

1

ACS Paragon Plus Environment


18

Abstract

19

Occurrence of microplastics (MPs) in the environments have been frequently reported.

20

However, studies on the quantification methods for MPs are still needed. Plastics are

21

polymers of different degrees of polymerization. In this study, alkali assisted thermal

22

hydrolysis was applied to depolymerize two plastics containing ester groups,

23

polycarbonate (PC) and polyethylene terephthalate (PET), in pentanol or butanol

24

system. By determining the concentrations of the depolymerized building block

25

compounds, i.e. bisphenol A (BPA) and para-phthalic acid (PTA), the amounts of PC

26

and PET MPs in the environmental samples were quantified. Recoveries of 87.2-97.1%

27

were obtained for the PC and PET plastics particles spiked in the landfill sludge. The

28

method was successfully applied to determine the occurrence of PC and PET MPs in

29

the samples of sludge, marine sediments, indoor dust, digestive residues in mussel and

30

clam, as well as in sea salt and rock salt. High concentrations of 246 and 430 mg/kg

31

were determined for PC and PET type MP in an indoor dust, respectively. In addition,

32

63.7 mg/kg of PC and 127 mg/kg of PET were detected in the digestive residues of a

33

clam.

2


Page 2 of 21

Page 3 of 21


34

INTRODUCTION

35

Microplastics (MPs) are members of the newest emerging contaminants in the

36

environments.1 Global plastics production was estimated to be 300 million metric tons

37

approximately,2 while around 10% of the produced plastics will enter the

38

environments and fragment into MPs eventually.3 Considering the low degradability

39

of most plastics, high levels of MPs might accumulate in the natural environments.4

40

Analysis methods for MPs mainly focus on their morphological and physical

41

characterization using different microscopy and spectroscopy instruments,5 while the

42

chemical characterization of MPs were identified by infrared and roman spectroscopy.

43

5,6

44

MPs from the samples, and might lead to great systematic errors.5 Chemical

45

identification of MPs is seldom performed with mass spectrometry. For example, a

46

pyrolysis-gas chromatography-mass spectrometry (Py-GCMS) method was used to

47

identify the separated MPs from marine sediments.7 Very recently, Py-GCMS was

48

applied to directly analyze the spiked MPs in fish.8 However, it failed to quantify MPs

49

in the original fish samples, because of the small indicator signals for quantification.8

However, MPs are quantified mainly by counting, which need pre-separation of

50

Polycarbonate (PC) and polyethylene terephthalate (PET) are important plastics

51

with estimated global annual production of 4.4 and 53.3 million tonnes,

52

respectively.9,10 Although the occurrence of PC and PET MPs in the environments has

53

been reported, 11-17 the detailed concentrations of these MPs in the environmental

54

samples are still unknown. To quantify the PC and PET MPs in the environments, we

55

developed a direct quantification method by depolymerizing these plastics and 3



56

determining the emerging building block compounds.

57

MATERIALS AND METHODS

58

Chemicals and environmental samples.

59

Standard of bisphenol A (BPA, ≥99%), para-phthalic acid (PTA, 99%) and

60

bisphenol A diglycidyl ether (BADGE, ≥95%), as well as 1-pentanol (>99%) and

61

1-butanol (99%) solvent were used. The PC and PET particles (0.075-0.15 mm) were

62

provided by Yineng Plastic Co. (Dongguan, China).

63

Landfill sludge was collected from a municipal sludge landfill in Tianjin, China.

64

Two marine sediments were collected from Bohai Bay, with the site location

65

information shown in Figure S1 in the Supporting Information. An indoor dust sample

66

was collected from a student dorm by sweeping of floors. The digestive residues from

67

two mussels and two clams purchased from a local market were also collected for the

68

MPs quantification. Commercial crude sea salt and rock salt were randomly

69

purchased from a supermarket. Environmental samples were stored at -20°C after

70

lyophilization.

71

Depolymerization of PC and PET MPs.

72

Alkali assisted heating depolymerization method has been studied for plastic

73

recycling.18 In this study, depolymerization of PC and PET was performed according

74

to alkaline hydrolysis reactions (Figure 1a&b). In brief, PET or PC particles together

75

with KOH was added into 1-pentanol solution. The system was heated at 135 °C for

76

different time. Then the depolymerization products in pentanol solution were

77

extracted by water. The water extracts were diluted 1×105 times, and 1.0 mL of the 4


Page 4 of 21

Page 5 of 21


78

diluted extract was taken out and spiked with and 13C12-BPA and D4-PTA (10 ng for

79

each) before the liquid chromatograph tandem mass spectrometer (LC-MS/MS)

80

analysis of the newly formed BPA and PTA. Detailed depolymerization procedure was

81

shown in Table S1. The depolymerization experiments were performed in triplicates.

82

The control experiments indicated BPA and PTA were stable during the

83

depolymerization process, while the procedure blank showed no detectable

84

background of BPA and PTA.

85

Depolymerization was also performed in the solvent of 1-butanol (Figure 1).

86

Then the butanol solvent was removed by rotary evaporation, and the solutes were

87

re-dissolved in water/acetonitrile (1:1 v/v) for LC-MS/MS analysis.

88

Spiking and recovery of PC and PET MPs in the sludge.

89

The recoveries of PC and PET MPs spiked in the landfill sludge were determined

90

at three spiking levels, i.e. 10, 100, and 1000 mg/kg, with the detailed spiking

91

procedure shown in Table S1. After sufficient mixing, 1.0 g of the sludge containing

92

1000 mg/kg of spiking MPs were weighted and transferred to the 1-pentanol

93

depolymerization system as described above. At the optimized reaction time, the free

94

form BPA and PTA were extracted twice by 30+20 mL of water. The water extract

95

was diluted 100 times, and 1.0 mL of the diluted extract spiked with 10 ng of

96

13

97

shown in Table S1, before the LC-MS/MS analysis.

C12-BPA and 10 ng of D4-PTA were purified by solid phase extraction (SPE) as

98

For determining the concentrations of BPA and PTA in the depolymerization

99

systems of samples with spiking MPs of 10 and 100 mg/kg, water extracts were 5



100

diluted 100 times and 10 times, respectively, before the SPE treatment. At each MPs

101

spiking levels, six parallels of spiked sludge samples were analyzed to identify the

102

error of determination. Six sludge samples without MPs spiked were analyzed as

103

blank controls. Therefore, contribution of the spiked MPs to the newly formed BPA

104

and PTA can be calculated. Accordingly, spiked PC and PET MPs amounts can be

105

calculated, with the equations introduced below.

106

Method application.

107

To determine PC and PET MPs in the sludge sample, BPA and PTA in the

108

original sludge were firstly detected in a control experiment. Sludge was treated in the

109

similar procedure, only with the heating process cancelled. Therefore, the newly

110

formed BPA and PTA from the depolymerization of PC and PET MPs can be

111

calculated by subtracting the amount of BPA and PTA in the original sludge from the

112

total BPA and PTA compounds in the depolymerized systems, and then the

113

corresponding occurrence of PC and PET MPs can be quantified. Determination of

114

PC and PET MPs in marine sediments, indoor dust and digestive residues from the

115

biological samples was also carried out with the same procedure. It should be noted

116

that, although BPA is also commonly used as the monomer of epoxy resin, 19 BADGE,

117

the monomer of epoxy resin, is proved to be stable in the depolymerization system,

118

while no emerging BPA was detected. Besides, in addition to PET, the newly formed

119

PTA during depolymerization may also come from other terephthalate type plastics,

120

such as polybutylene terephthalate (PBT) and polytrimethylene terephthalate plastics

121

(PTT). However, considering the much lower production of PBT and PTT and their 6


Page 6 of 21

Page 7 of 21


122

similar structure and application with PET plastics,20 PET calculated in this study

123

could represent the occurrence of all these three plastics.

124

Two hundred grams of the sea salt or rock salt were weighted and dissolved in

125

hot water, respectively. Then the insoluble matters were filtered by 0.22 µm nylon

126

membrane filters, and dried to a constant weight at 48 oC for 24h. Then the insoluble

127

matters were depolymerized in 1-butanol for 30 min. After the addition of 10 ng of

128

13

129

and the target compounds were re-dissolved in water/acetonitrile (1:1 v/v) and filtered

130

by nylon membrane filter before analysis.

C12-BPA and 10 ng of D4-PTA, butanol solvent was removed by rotary evaporation,

131

For each sample of sludge, marine sediments, dust, digestive residues and salts,

132

two parallel samples were analyzed and the average values were calculated. It should

133

be note that, the newly formed BPA and PTA during the depolymerization was

134

assumed to be derived entirely from the depolymerization of PC and PET in the

135

samples. This will be further discussed in detail below.

136

Instrument analysis.

137

Detailed information of chromatographic separation and tandem MS system to

138

quantify BPA and PTA was shown in Table S2 and S3. The MRM chromatograms of

139

BPA and PTA in the depolymerized sludge were shown in Figure S2, and their

140

concentrations were corrected by the corresponding internal standards, i.e. 13C12-BPA

141

and D4-PTA, respectively.

142

RESULTS AND DISCUSSION

143

Depolymerization of PC and PET MPs in pentanol and butanol 7



Page 8 of 21

144

Both of PC and PET MPs can be readily depolymerized via hydrolysis within 30

145

min in 1-pentanol or 1-butanol solution with potassium hydroxide. Visual

146

disappearance of PC and PET particles in both of the 1-pentanol and 1-butanol

147

solutions can be observed. Accordingly, formation of BPA and PTA can be determined.

148

For example, at 30 min, 0.42 g of BPA was detected in the 1-pentanol system initially

149

containing 0.5 g of PC MPs (Figure 1a). Based on the structural formula of PC

150

polymer,

151

approximately 89.5% (f(BPA-2H), w/w) in PC plastic, indicating a theoretical mass of

152

0.45 g of emerging BPA might form from 0.5 g of depolymerized PC plastic.

153

Therefore, >93% of depolymerization efficiency of PC plastic within 30 min can be

154

verified.

i.e.

[-O-C6H4-C(CH3)2-C6H4-O-C(O)-]n,

(BPA-2H)

accounts

for

155

Similarly, 0.42 g of PTA formed at 30 min in the hydrolysis system containing

156

1-pentanol and 0.5 g of PET plastic (Figure 1b). According to the PET polymer

157

structure formula, i.e. [-C(O)-C6H4-C(O)-O-CH2-CH2-]n, (PTA-H2O) accounts for

158

approximately 77.4% (f(PTA-H2O), w/w) in PET plastic. Therefore, 0.43 g of emerging

159

PTA might form from 0.5 g of depolymerized PET. This demonstrated almost all of

160

PTA (98%) depolymerized from PET plastic. Similar depolymerization efficiencies

161

were also obtained in the solution of 1-butanol. Therefore, by determining the amount

162

of hydrolysis products, i.e. BPA and PTA, quantification of PC and PET plastics can

163

be conducted according to equation 1&2, where f(BPA-2H) and f(PTA-H2O) are mass

164

percentage of (BPA-2H) and (PTA-H2O) in PC and PET plastics respectively, and

165

MW represents molecular weight. 8


Page 9 of 21


166

Unheated control indicated that, heating is necessary for the depolymerization.

167

At room temperature (25 oC), the plastic particles were insoluble in pentanol and

168

butanol, with the mass changes of PC or PET particles of < 2%.

169

=

170

#$ =

171

( ) ! ( )× "( ) (& ( % % )× "(&

')

(1)

')

! &

(2)

Quality Assurance / Quality Control.

172

As mentioned above, a mass ratio of newly formed BPA (∆BPA=()*+,-. −

173

()*+,-. ) and the depolymerized PC MPs of 90% can be theoretically assumed,

174

and the method recovery of PC MPs could be calculated as

175

Similarly, recovery of PET MPs spiked in the sludge samples could be calculated by

176

the amount of newly formed PTA (∆PTA= $)*+,-. − $)*+,-. ) as

177

∆ % /9:% 56

∆ /23% 56

× 100%.

× 100%. Ideal recoveries of PC and PET MPs spiked in the sludge samples

178

can be obtained for MPs at three levels in 1-pentanol. In sludge samples with 1000

179

mg/kg of PC or PET MPs spiked, 843 mg/kg of BPA or 850 mg/kg of PTA can be

180

determined in the depolymerized samples. In comparison, 14.1 mg/kg of BPA or 12.7

181

mg/kg of PTA were detected in the background samples without spiked MPs. This

182

indicates the concentrations of newly formed BPA and PTA of 829 and 837 mg/kg

183

(Figure S3a), accounting for the recoveries of 92.0±1.1% and 97.1±2.1% for the

184

spiked PC and PET MPs in the sludge (n=6) (Table S4). Using the same method, the

185

newly formed BPA by depolymerization of the spiked PC MPs at 100 and 10 mg/kg in

186

the sludge were determined to be 72.3 and 8.73 mg/kg, while the newly formed PTA

187

were 78.9 and 7.56 mg/kg, respectively (Figure S3a). Therefore, the ideal recoveries 9



188

of 87.2~92.0 % (for PC) and 87.9~97.1 % (for PET) can be obtained for the different

189

spiking levels MPs in the sludge (Table S4). Depolymerized BPA and PTA were also

190

detected in the 1-butanol depolymerization systems, but with greater deviation values,

191

especially for the spiked MPs at 100 and 10 mg/kg (Figure S3b). Detection recoveries

192

of PC and PET particles were lower if the 1-butanol depolymerization and rotary

193

evaporation concentration process were applied (Table S4). This was due to the more

194

significant matrix interference effects of this method, since no purification treatment

195

was included in the butanol depolymerization-rotary evaporation process. In

196

comparison, both of the water extraction and SPE used in the1-pentanol

197

depolymerization method could purify the samples efficiently.

198

Instrumental calibration was verified by the injection of a 10-point calibration

199

standard ranging in concentrations from 0.1 to 20 µg/L for BPA and 0.5 to 200 µg/L

200

for PTA, with the regression coefficients (R) of the calibration curves ≥0.99.

201

Accordingly, the linear ranges of this method for PC and PET MPs in sludge was

202

accounted for 5.56~1110 and 29.1~11600 µg/kg, respectively. The limits of

203

quantification for PC and PET MPs were calculated to be 8.32 and 53.0 µg/kg, based

204

on the instrumental limits of quantification (S/N 10) and the recoveries of BPA and

205

PTA.

206

Determination of PC and PET MPs in environmental samples

207

To determine PC and PET MPs in the environmental samples, the concentrations

208

of original free form BPA and PTA should be deducted. In the unheated treatment,

209

5.03 mg/kg of BPA and 2.41 mg/kg of PTA were determined in sludge sample. After 10


Page 10 of 21

Page 11 of 21


210

these background monomers were deducted, PC MPs in the sludge was calculated to

211

be 10.1 mg/kg, while PET was 12.0 mg/kg (Table 1), according to eq. 1&2,

212

respectively. Although MPs in the marine sediments and Lagoon sediments were

213

quantified by counting,

214

reported until now. In this study, in the marine sediment A, 1.60 mg/kg of PC MPs

215

and 10.3 mg/kg of PET MPs were detected (Table 1). Very high concentrations of PC

216

(246 mg/kg) and PET MPs (430 mg/kg) were detected in the indoor dust sampled in

217

Tianjin, indicating high exposure risk of these MPs in human through dust.

12,16,21

no detailed mass concentration of MPs has been

218

Bivalves are commonly applied as indictors of environmental contaminants.22 PC

219

MPs of 2.33 and 4.41 mg/kg were detected in the digestive residues from mussel A

220

and B, while the concentrations for PET MPs were calculated to be 75.4 and 17.5

221

mg/kg, respectively (Table 1). In addition, much higher PC and PET MPs were

222

detected in the digestive residues from a clam, with concentrations of 63.7 and 127

223

mg/kg, respectively.

224

MPs can be detected in sea salts.14 In the two commercial salts, i.e. a sea salt and

225

a rock salt, the solid insoluble matters were weighted to be 3280 and 490 mg/kg,

226

respectively. These solid matters were depolymerized in 1-butanol. In the insoluble

227

matters from sea salts, the PC and PET MPs were calculated to be 26.6 and 31.0

228

mg/kg in the insoluble matters. Therefore, the concentrations of PC and PET MPs in

229

the sea salts were 0.088 and 0.102 mg/kg, respectively (Table 1). By comparison,

230

much less concentrations of MPs, 1×10-4 mg/kg for PC and 2×10-3 mg/kg for PET,

231

were detected in the rock salts. 11



Page 12 of 21

232

In current method, separation of MPs from the samples is unnecessary, which

233

increases the analyzing efficiency and avoids the MPs loss or error-picking caused by

234

separation. Attention should also be paid to the specificity of the building block

235

compound of MPs. For instance, for PC MPs containing other key building block

236

compounds, e.g. bisphenol S (BPS), detection of only BPA will lead to an

237

underestimation.

238

depolymerization process was assumed to be derived entirely from the hydrolysis of

239

PC and PET MPs in the samples, respectively. Although BPA was also added into

240

some plastic materials as an antioxidant, it may affect little to the PC quantification.

241

Firstly, contribution of BPA additive is much lower than that of the building block

242

BPA in PC. For example, BPA released from a PVC plastic was six orders of

243

magnitude lower than that from the depolymerized PC plastic (Table S5). Secondly,

244

most released BPA from the PVC particles can migrate in the non-depolymerization

245

treatment (Table S5), which can be deducted as “ ()*+,-. ” according to

246

equation (1). Similarly, PTA is also added in PVC plastic as a plasticizer in the form

247

of lipids. However, emerging PTA released from PVC plastics during the

248

depolymerization process was four to five orders of magnitude lower than that from

249

PET (Table S5), indicating limited contribution of PVC to detected PTA after the

250

depolymerization process. Besides, it should be noted that the particle size

251

distribution of MPs in the samples cannot be analyzed by this method. In addition, if

252

polymers containing the same building block compound present and can be

253

depolymerized at the same condition, it will be difficult to distinguish the source of

Besides,

the

newly

formed

BPA and

12


PTA during

the

Page 13 of 21


254

the depolymerization products.

255

ASSOCIATED CONTENT

256

Supporting Information

257

Additional information as noted in the text. This material is available free of charge

258

via the internet at http://pubs.acs.org.

259

Detailed procedure of depolymerization, MPs spiking, and SPE (Table S1); HPLC

260

gradient elution programs for BPA and PTA (Table S2); MS parameters for the

261

analysis of BPA and PTA (Table S3); Recoveries of the spiked MPs in sludge samples

262

(Table S4); Amounts of BPA and PTA (mg) released from 0.5 g of PVC a, PC or PET

263

plastics before and after depolymerization (Table S5); Sampling location of marine

264

sediment samples (Figure S1); Chromatograms of BPA and PTA in the extracts from

265

depolymerized sludge without/with PET and PC MPs spiked (Figure S2); The

266

detected concentrations of BPA and PTA depolymerized from spiked MPs at different

267

spiking levels in 1-pentanol or 1-butanol system. (Figure S3).

268

AUTHOR INFORMATION

269

*Corresponding Author

270

Phone:

271

[email protected]

272

ORCID

273

Lei Wang: 0000-0002-8193-9954

274

Junjie Zhang: 0000-0002-4383-1096

275

Shaogang Hou: 0000-0001-6192-9428

+86-22-2350-4262.

Fax:

+86-22-2350-8807.

13


E-mail:


Page 14 of 21

276

Hongwen Sun: 0000-0003-1948-5047

277

Notes

278

The authors declare that there are no conflicts of interest.

279

ACKNOWLEDGEMENTS

280

This work was supported by National Science Foundation for Natural Science of

281

China

282

(2017CB41722304), and 111 Program, Ministry of Education, China (T2017002).

283

REFERENCES

284

(1) Sedlak, D. Three Lessons for the microplastics voyage. Environ. Sci. Technol.

285

(41722304),

National

Key

Basic

Research

Program

of

China

2017, 51, 7747-7748.

286

(2) Jambeck, J. R.; Geyer, R.; Wilcox, C.; Siegler, T. R.; Perryman, M.; Andrady, A.;

287

Narayan, A.; Law, K. L. Plastic waste inputs from land into the ocean. Science

288

2015, 347, 768-771.

289

(3) Thompson, R. C.; Olsen, Y.; Mitchell, R. P.; Davis, A.; Rowland, S. J.; John, A. W.;

290

McGonigle, D.; Russell, A. E. Lost at sea: where is all the plastic?. Science 2004,

291

304, 838-838.

292 293

(4) Law, K. L.; Thompson, R. C. Microplastics in the seas. Science 2014, 345, 144-145.

294

(5) Rocha-Santos, T.; Duarte, A. C. A critical overview of the analytical approaches to

295

the occurrence, the fate and the behavior of microplastics in the environment.

296

TrAC Trends Anal. Chem. 2015, 65, 47-53.

297

(6) Duemichen, E.; Eisentraut, P.; Bannick, C. G; Barthel, A. K.; Senz, R.; Braun, U. 14


Page 15 of 21


298

Fast identification of microplastics in complex environmental samples by a

299

thermal degradation method. Chemosphere 2017, 174, 572-584.

300

(7) Dekiff, J. H.; Remy, D.; Klasmeier, J.; Fries, E. Occurrence and spatial distribution

301

of microplastics in sediments from Norderney. Environ. Pollut. 2014, 186,

302

248-256.

303

(8) Fischer, M.; Scholz-Böttcher, B. M. Simultaneous trace identification and

304

quantification of common types of microplastics in environmental samples by

305

pyrolysis-gas chromatography–mass spectrometry. Environ. Sci. Technol. 2017, 51,

306

5052-5060.

307

(9) The Essential Chemical Industry (ECI) – online. Polycarbonates. 2016,

308

(http://www.essentialchemicalindustry.org/polymers/polycarbonates.html)

309

October 30, 2017).

310

(last

access,

(10) The Essential Chemical Industry (ECI) – online. Polyesters. 2017,

311

(http://www.essentialchemicalindustry.org/polymers/polyesters.html)

312

October 30, 2017).

(last

access,

313

(11) Käppler, A.; Fischer, D.; Oberbeckmann, S.; Schernewski, G.; Labrenz, M.;

314

Eichhorn, K. J.; Voit, B. Analysis of environmental microplastics by vibrational

315

microspectroscopy: FTIR, Raman or both?. Anal. Bioanal. Chem. 2016, 408,

316

8377-8391.

317

(12) Qiu, Q.; Peng, J.; Yu, X.; Chen, F.; Wang, J.; Dong, F. Occurrence of

318

microplastics in the coastal marine environment: First observation on sediment

319

of China. Mar. Pollut. Bull. 2015, 98, 274-280. 15



320 321

(13) Li, J.; Yang, D.; Li, L.; Jabeen, K.; Shi, H. Microplastics in commercial bivalves from China. Environ. Pollut. 2015, 207, 190-195.

322

(14) Yang, D.; Shi, H.; Li, L.; Li, J.; Jabeen, K.; Kolandhasamy, P. Microplastic

323

pollution in table salts from China. Environ. Sci. Technol. 2015, 49,

324

13622-13627.

325

(15) Zhang, K.; Xiong, X.; Hu, H.; Wu, C.; Bi, Y.; Wu, Y.; Zhou, B.; Lam, P. K.; Liu,

326

J. Occurrence and characteristics of microplastic pollution in Xiangxi Bay of

327

Three Gorges Reservoir, China. Environ. Sci. Technol. 2017, 51, 3794-3801.

328

(16) Vianello, A.; Boldrin, A.; Guerriero, P.; Moschino, V.; Rella, R.; Sturaro, A.; Da

329

Ros, L. Microplastic particles in sediments of Lagoon of Venice, Italy: First

330

observations on occurrence, spatial patterns and identification. Estuarine,

331

Coastal Shelf Sci. 2013, 130, 54-61.

332 333

(17) Fuller, S.; Gautam, A. A procedure for measuring microplastics using pressurized fluid extraction. Environ. Sci. Technol. 2016, 50, 5774-5780

334

(18) Wan, B. Z.; Kao, C. Y.; Cheng, W. H. Kinetics of depolymerization of poly

335

(ethylene terephthalate) in a potassium hydroxide solution. Ind. Eng. Chem. Res.

336

2001, 40, 509-514.

337 338 339 340 341

(19) Groshart, C.; Okkeman, P.; Pijnenburg, A. Chemical Study on Bisphenol A; RIKZ: Rijkswaterstaat, 2001. (20) Plastic Europe, 2016. Plastics – the Facts 2016: An analysis of European plasticsproduction, demand and waste data. 2016. (21) Liebezeit, G.; Dubaish, F. Microplastics in beaches of the East Frisian islands 16


Page 16 of 21

Page 17 of 21


342

Spiekeroog and Kachelotplate. Bull. Environ. Contam. Toxicol. 2012, 89,

343

213-217.

344

(22) Wang, L.; Sun, H.; Yang, L.; He, C.; Wu, W.; Sun, S. Liquid

345

chromatography/mass spectrometry analysis of perfluoroalkyl carboxylic acids

346

and perfluorooctanesulfonate in bivalve shells: Extraction method optimization.

347

J. Chromatog. A, 2010, 1217, 436-442.

17



FIGURE LEGEND Figure 1. The depolymerization efficiencies of PC (a) and PET (b) plastics at different time in 1-pentanol and 1-butanol. The diagram represents average value of the triplicates, while the error bar represents SD.

18


Page 18 of 21

Page 19 of 21


Figure 1

(a)

(b)

19



Page 20 of 21

Table 1. BPA, PTA and the calculated PC and PET MPs in the environmental samples (mg/kg) a BPAnon-depolym BPAdepolym PC MP Sludge

PTAnon-depolym PTAdepolym PET MP

5.03

14.1

10.1

2.41

12.7

12.0

Sediment A

0.0214

1.47

1.60

0.482

9.31

10.3

Sediment B

0.208

0.898

0.765

0.318

2.84

2.93

Indoor dust

0.770

222

246

217

587

430

Mussel digestive residues Ab

1.20

3.30

2.33

4.17

69.0

75.4

Mussel digestive residues Bb

0.234

4.20

4.41

4.31

19.4

17.5

Clam digestive residues Ab

0.740

58.1

63.7

7.04

116

127

Clam digestive residues Bb

0.659

4.91

4.72

14.8

19.8

5.81

SIMsc in sea salt

A Simple Method for Quantifying Polycarbonate ... - ACS Publications

Recommend Documents