Supporting Information

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1 Supporting Information 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 Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin , China * Corresponding author: L. Wang Nankai University #38Tongyan Road Tianjin, China Tel: Fax: wang2007@nankai.edu.cn Pages: 10 Tables: 5 Figure: 3 S1

2 Tables: 5 Table S1. Detailed procedure of depolymerization, MPs spiking, and solid phase extraction Table S2. HPLC gradient elution programs for BPA and PTA Table S3. MS parameters for the analysis of BPA and PTA Table S4. Recoveries ± RSDs (%) of the spiked MPs in sludge samples (n = 6) Table S5. Amounts of BPA and PTA (mg) released from 0.5 g of PVC, PC or PET plastics before and after depolymerization Figures: 2 Figure S1. Sampling location of the marine sediment samples in Bohai Bay Figure S2. Chromatograms of BPA and PTA in the extracts from depolymerized sludge with/without PET and PC MPs at low spiking level (10 mg/kg) Figure S3. The detected concentrations of BPA and PTA depolymerized from the spiked PC and PET particles at different spiking levels (10, 100, 1000 mg/kg) in (a) 1-pentanol or (b) 1-butanol system. The diagram represents average value of six replicates, while the error bar represents SD S2

3 Table S1. Detailed procedure of depolymerization, MPs spiking, and solid phase extraction Depolymerization PET (0.5 g) or PC (0.5 g) particles ( mm) together with KOH (1.0 g) was added in a 100 ml rounding bottom flask, which contained 20 ml of 1-pentanol. The system was heated at 135 C in a heating sleeve, while the condense pipe was installed to reflux the solvent and the target compounds. After different heating time (5, 15, 30, 60, 90, 120 min), the pentanol solution was transferred to a 60 ml glass tube after it had cooled to room temperature. The flask was rinsed three times with 10 ml water for each time, while the rinse water was also transferred to the glass tube. To extract the depolymerization products from pentanol, the glass tube was then sealed and shaken at 180 rpm for 5 min, and then centrifuged at 3000 rpm for 5 min. After that, the upper organic phase of pentanol was moved to another tube, and 20 ml of fresh water was added to pentanol to repeat the extraction process. The water extracts were combined and diluted times. MPs spiking into the samples To obtain sludge sample with spiking MPs at 1000 mg/kg, 10 mg of PC or PET particles were added into 10 g of freeze-dried sludge. To obtain sample with spiking MPs at 100 mg/kg, 1.0 g of MPs spiked sludge (1000 mg/kg) and 9.0 g of original freeze-dried sludge were fully mixed by a vortex mixer. Furthermore, sludge with 10 mg/kg of spiked MPs was prepared by diluting samples with 100 mg/kg of MPs with original dry sludge. Solid phase extraction 1.0 ml of extracted samples were diluted with HPLC grade water to 10 ml and adjusted to ph 2-3 with HCL before SPE. The cartridges (Poly-SeryHLB 6 cc/200 mg; CNW, Shanghai, China) were conditioned by 12 ml of MeOH and equilibrated with 12 ml of HPLC grade water. Then, the extracts were passed through the cartridge. Cartridges were washed by 4 ml of HPLC grade water containing 10% MeOH before dryness. Finally, the target analytes were eluted with 5 ml of MeOH. The solvent was evaporated to near dryness under a gentle stream of nitrogen, reconstituted with a 1 ml of water/acetonitrile (1:1 v/v) and transferred into an auto-sampler vial for LC-MS/MS analysis. S3

4 Table S2. HPLC gradient elution programs for BPA and PTA a Time (min) BPA PTA Time (min) A (%) B (%) A (%) B (%) a Aglient 1260 system (Aglient Technologies, Inc., Sanata, CA, U.S) was used in the chromatographic separation. A Boltimate C18 column (100 mm 2.1 mm, 2.7 μm, Welch Materials, Inc., Shanghai, China) and a Polar RP C18 column (100 mm 3 mm, 3.0μm, Welch Materials, Inc., Shanghai, China) were applied to detect BPA and PTA, respectively. The mobile phase was comprised of MeOH (A) and HPLC grade water (0.01% v/v formic acid for PTA, 0.4 mm NH4F for BPA) (B),The flow rates of 300 and 600 μl/min were applied for BPA and PTA, respectively; S4

5 Table S3. MS parameters for the analysis of BPA and PTA a compounds Precursor ion (m/z) Quantification/Qualitative product ion (m/z) Fragment Voltage(V) b Collision energy (V) b BPA / /88 16/24 13 C 6-BPA / /88 16/24 PTA / /80 10/20 D 4-PTA / /80 10/20 a Identification and quantification of BPA and PTA were performed with a triple quadrupole mass spectrometer G6460C (ESI MS/MS; Aglient Technologies, Inc., Sanata, CA, U.S.). The dry gas and sheath gas temperatures were 300 and 400, respectively; The dry gas and sheath gas flows were 8 L/min and 12 L/min, respectively. The capillary voltage was 3.5kV. The nebulizer gas pressure was set at 45 psi; b coefficient for quantitative product ion / coefficient for qualitative product ion were shown respectively. S5

6 Table S4. Recoveries ± RSDs (%) of the spiked MPs in sludge samples (n = 6) in 1-pentanol at low spiking level a at medium spiking level a at high spiking level a PC 89.3± ± ±1.1 PET 87.9± ± ±2.1 in 1-butanol PC 59.4± ± ±2.4 PET 54.0± ± ±1.8 a The low, medium and high spiking levels of PC and PET MPs were 10, 100 and 1000 mg/kg, respectively; S6

7 Table S5. Amounts of BPA and PTA (mg) released from 0.5 g of PVC a, PC or PET plastics before and after depolymerization BPA non-depolym PTA non-depolym BPA depolym PTA depolym PVC A <LOQ <LOQ PVC B PET <LOQ <LOQ <LOQ 430 PC <LOQ <LOQ 413 <LOQ a Two PVC pipes, namely PVC A and PVC B, were randomly purchased from a local building material market, which were ground to 2 mm of particles for further treatment. S7

8 Figure S1 Tianjin Bohai Bay B A Figure S1. Sampling location of the marine sediment samples in Bohai Bay. S8

9 Figure S2 BPA: 227.1>212.1 Quantification ions BPA: 227.1>133.0 Qualitative ions with PC spiked without PC spiked PTA: 165.0>77.0 Quantification ions PTA: 165.0>121.0 Qualitative ions with PET spiked without PET spiked Figure S2. Chromatograms of BPA and PTA in the extracts from depolymerized sludge without/with PET and PC MPs spiked (at low spiking level of 10 mg/kg). S9

10 (a) (b) Figure S3. The detected concentrations of BPA and PTA depolymerized from the spiked PC and PET particles at different spiking levels (10, 100, 1000 mg/kg) in (a) 1-pentanol or (b) 1-butanol system. The diagram represents average value of six replicates, while the error bar represents SD. S10