Diethyl phthalate

All PEs standards including dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP) and bis(2-ethylhexyl) phthalate (DEHP) were purchased from Sigma Aldrich, Germany. The purities of all PEs were >98%. A 1000 μg mL⁻¹ stock standard solution of each standard was prepared in methanol and stored in glass vials at −20 °C. The standard working solution mixtures (0.001–1.00 μg mL⁻¹) were prepared daily by diluting appropriate aliquots of the stock standard solutions to obtain the required concentrations and stored at 4 °C. HPLC grade methanol, acetonitrile and acetone were purchased from Sigma-Aldrich, Germany. Chloroform (CHCl₃), dichloromethane (CH₂Cl₂), chlorobenzene (C₆H₅Cl), carbon tetrachloride (CCl₄) and sodium chloride (NaCl) were from Merck (Darmstadt, Germany). Deionized water (18.2 mΩ cm) was prepared by Pure Lab Ultra water system (ELGA, High Wycombe, UK) and used in all procedures. Glass tight microsyringes (Hamilton, Nevada, USA) were used for measuring the extracted sediment volume and for the DLLME procedure. All glassware used were rinsed with deionized water then acetone before drying at 300 °C for at least 5 hours. Moreover blank runs were done for each set of samples.

Unless stated otherwise all chemicals used were of analytical grade, or in the case of chromatographic solvents, gradient grade or ULC/MS grade (mass spectrometry). Bisphenol A (BPA, purity 95%) was provided by Fluka (Sigma-Aldrich, St. Louis, MO, United States; now belonging to Merck Group, Darmstadt, Germany). Dibutyl phthalate (DBP, purity > 99%), diethyl phthalate (DEP, purity 99.5%), and piperonyl butoxide (PB) of technical grade (purity 90%) were purchased from Sigma-Aldrich. 2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS, purity > 98%) was obtained from AppliChem (Darmstadt, Germany). All other chemicals were purchased from Merck, Sigma-Aldrich and Th. Geyer GmbH (Renningen, Germany).

All reference standards for target compounds were of high purity grade (>99%). Methylisothiazolinone (MI), benzisothiazolinone (BIT), dimethyl phthalate (DMP), diethyl phthalate (DEP), and their internal standards (dimethyl phthalate-3,4,5,6-d4 and diethyl phthalate-3,4,5,6-d4) were obtained from Sigma-Aldrich, methylchloroisothiazolinone (CMI), and its internal standard benzoisothiazol-3-one-13C6 was supplied by Toronto Research Chemicals. Other solvents, including methyl tert-butyl ether (MTBE), were purchased from Duksan Pure Chemicals, South Korea. Dichloromethane (DCM), methanol, and ethyl acetate were purchased from Fisher Scientific Korea Ltd. HPLC grade water was supplied by Avantor Performance Materials Korea. Individual stock solutions of all target compounds and internal standards were prepared in ethanol and stored at −20 °C before use.

Cypermethrin (Lot# BCCB1117), Diethyl phthalate (Lot #BCBZ8989), Vinclozolin (Lot #BCBZ5052), 17α-ethinyl estradiol (Lot #WXBC9894V), Perfluorooctanesulfonic acid (#0000091932) and Atrazine (Lot# BCBZ3835) were obtained from SIGMA-ALDRICH INC. P.O. (St. Louis, MO, USA). Unless otherwise stated, all compounds were purchased from Sigma-Aldrich. All solutions used for in vivo infusions were prepared using nonpyrogenic saline (0.9% NaCl; Baxter Healthcare Ltd., Thetford, Norfolk, UK).

The chemicals CuSO₄, MnSO₄, benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), dicyclohexyl phthalate (DCP), diethyl phthalate (DEP), di-(2-ethylhexyl) phthalate (DEHP), acetosyringone (AS), syringaldehyde (SA), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), vanillin (VA), N-hydroxyphthalimide (HPI), (2,2,6,6-tetramethylpiperidin-1-yl) oxyl (TEMPO), and hexane, along with other solvents (analytical grade, 99.0% purity), were purchased from Sigma-Aldrich (Merck/Millipore Sigma, St. Louis, Missouri, USA). The chemical structures of the compounds used in this study are shown in Figure 1A and Supplementary Table S1. Laccases from three fungi (Aspergillus sp., Rhus vernicifera, and Trametes versicolor) were purchased from Sigma-Aldrich (Merck/Millipore Sigma, St. Louis, Missouri, USA).

Monobutyl phthalate (MBP, 99% purity), di-n-butyl phthalate (DBP, 99%), diethylhexyl phthalate (DEHP, 99.5%), diethyl phthalate (DEP, 99%), dimethyl phthalate (DMP, 99%), phthalic acid (PA, > 99.5%), 2-ethyl-1-hexanol (99.6%), terephthalic acid (98%), and isophthalic acid (99%) were purchased from Sigma Aldrich Chemie GmbH (Hamburg, Germany). Acetonitrile, ethyl acetate, hexane, and formic acid were of HPLC grade and purchased from Carl Roth (Karlsruhe, Germany).

Acetonitrile HPLC grade, methanol, and hexane GC-MS grade were supplied by Merck (Darmstadt, Germany). Ethanol for analysis was supplied by Merck (Darmstadt, Germany). The 2-butoxyethanol, spectrophotometric grade with a purity of ≥99.0%, 2,2-dimethyl-1,3-propanediol with a purity of 99.0%, octanal with a purity of 99%, D-Limonene, ε-Caprolactam; 2,6-Di-tert-butyl-1,4-benzoquinone with a purity of 98.0%, diethyl phthalate with a purity of 99.5%, benzophenone with a purity of ≥99.0%, benzoic acid with a purity of 99.5%, vanillin with a purity of 99.0%, 2,4-ditertbutylphenol with a purity of 99.0%, and α-terpineol were purchased from Sigma Aldrich (Steinheim, Germany). Nonanal with purity of 98.7% was purchased from Supelco (Bellefonte, PA, USA). The 2-phenoxyethanol with purity of ≥99.0% was supplied by Fluka (Seelze, Germany). Working solutions were prepared by diluting different amounts of the stock standard solution in methanol.