Milli q gradient a10

N-hexane (≥95 %, PESTINORM®), acetone (Anala® NORMAPUR) and 2-propanol (Anala® NORMAPUR) were purchased as solvents from VWR Chemicals (Vienna, Austria). Ultra-pure water was obtained from a water purification system (Milli-Q gradient A 10, Milipore, Merck, Darmstadt, Germany). Norit® SAE SUPER (Cabot Norit Nederland B.V., Klazienaveen, The Netherlands) was used as activated carbon powder. Grade 50 filter paper was purchased from Whatman (GE Heathcare, Dassel, Germany). Copper wire (0.6 mm thickness) was from HSB Elektro (Uslar, Germany). DEHP (analytical standard) and DEHP-d4 (Pestanal®, analytical standard) were purchased from Merck (Darmstadt, Germany). DEHP and DEHP-d4 stock standards (each 5000 μg mL⁻¹) were prepared in 2-propanol. From these working standards of DEHP (50 μg mL⁻¹ and 500 μg mL⁻¹) and DEHP-d4 (50 μg mL⁻¹) were made in 2-propanol. All standards were stored at 4 °C in dark in amber brown glass vials closed with caps equipped with teflon septa. A 1 mM potassium chloride (KCl) solution was used as background solution to stabilise the ionic strength. PVC pellets were purchased from Industrie Generali spa (Samarate, Italy) and contained ∼35 % of DEHP. Each leaching or spiking experiment was conducted in triplicates, including three blanks.

Phloroglucinol, L-ascorbic acid, sodium acetate, Folin–Ciocalteu reagent, hydrochloric acid 37%, formic acid 98%, and phosphoric acid 85% were purchased from Sigma-Aldrich Co., St. Louis, MO, USA; sodium carbonate and acetic acid 100% were purchased from Merck KGaA, Darmstadt, Germany. Commercial ethanol 95% v/v was used for the preparation of the extracts. Methanol high-performance liquid chromatography (HPLC) grade (VWR Chemicals, Radnor, PA, USA) and acetonitrile HPLC grade (Merck KGaA, Darmstadt, Germany) were used for the high-performance liquid chromatography (HPLC) analyses. The standards used for the Phloroglucinolysis method were (+)-catechin, (−)-epicatechin, and (−)-epicatechin-3-O-gallate (Sigma Aldrich Co., St. Louis, MO, USA). C-18 solid-phase extraction cartridges (Sep-Pak tC18 1g) were purchased from Waters, Milford, MA, USA. Ultrapure water was used throughout the experiment (Milli-Q gradient A10—Millipore Corporation, Billerica, MA, USA).

Rongalite, dopamine hydrochloride and resorcinol were purchased from Macklin Company (Shanghai, China). Formaldehyde solution (37–40%) was obtained from J &K Scientific (Beijing, China). Glucose, sucrose, glutamate, prolamin and Ca²⁺ were supplied by Aladdin Industrial Corporation (Shanghai, China). Sodium carbonate, sodium hydroxide and hydrochloric acid were purchased from Sinopharm Chemical Reagent Co., Ltd. (Beijing, China). All the reagents were analytical grade.
Sterile syringe filters (0.45 μm) were obtained from Merck (Merck Millipore, Burlington, MA, USA). White opaque microplates were supplied by Corning Ltd. (Corning Life Science, Hartford, NY, USA). Ultra-pure water was used in all aqueous solution and was produced by Millipore purification system (MilliQ gradient A10, Millipore, Bedford, MA, USA). Fluorescence excitation and emission spectra, absorption spectra, optical density, and fluorescence intensity were measured using a microplate reader (SpectraMax M2e, Molecular Devices, San Jose, CA, USA). The pH values were measured by a pH meter supplied by Thermo Fisher Scientific Inc. (Orion 4 Star, Beverly, MA, USA). The mass spectrum analysis was performed on the electrospray ionization (ESI)-TRIPLE QUAD 5500 (AB SCIEX, Framingham, MA, USA.) in the negative ion mode.