Milli q system

Part of the oilfield sand was washed with ultrapure water (Milli-Q system, resistivity 18.2MΩcm) and roasted at 600°C for 3 h in a muffle furnace (Thermolyne Industrial Benchtop Muffle Furnaces, Thermo Fisher Scientific) to remove surface organic matter and used as treated sand (Tian et al., 2012 (link)). After the temperature treatment, the sand was cooled to room temperature inside the furnace; and, later stored under vacuum conditions for further characterization.

The certified standard solutions of Cd, Cr, Pb, As, and Hg (1 mg/mL) were purchased from the National Institute of Metrology, China. The working standard solutions were prepared from the standard solutions with Milli-Q water (18.2 MΩ cm resistivity) from a Millipore Milli-Q system (Thermo Scientific EASYpure II, Waltham, MA, USA). Calibration was performed by analyzing the prepared working standard solutions and two agent blank samples. Concentrations of Cd, Cr, and Pb were determined using an Inductively Coupled Plasma-Atomic Emission Spectrometry instrument (SPECTRO Analytical Instruments GmbH, Kleve, Germany) with axial viewing configuration. Total concentrations of As and Hg were determined using Atomic Fluorescence Spectrometry (AFS-930) (Beijing Jitian instrument Ltd., Beijing, China).

316L SSM (1 cm × 2.5 cm, 200 mesh) was purchased from good fellow (Cambridge, Ltd., Shanghai, China). Pt plate (0.6 cm × 0.2 cm), Na₂MoO₄·2H₂O (99%), CH₄N₂S (99%), H₂SO₄ (95%), HCL (37%), ethanol were purchased from Sinopharm Chemical Reagent Co., Ltd., Shanghai, China. All chemicals were analytical grade and used as received without further purification. The deionized water (~18.2 mΩ.cm) used throughout all experiments was purified by Milli-Q system (Thermo Fisher Scientific, Massachusetts, MA, USA).

Sodium alginate, sucrose, calcium chloride (CaCl₂), sodium carbonate (Na₂CO₃), calcium chloride dihydrate (CaCl₂(H₂O)₂), sodium hydroxide (NaOH), sodium citrate (Na₃C₆H₅O₇(H₂O)₂), hydrochloric acid (HCl), potassium chloride (KCl), potassium dihydrogen phosphate (KH₂PO₄), sodium acetate (CH₃COONa), sodium chloride (NaCl), magnesium chloride hexahydrate (MgCl₂(H₂O)₆), ammonium carbonate (NH₄)₂CO₃, gallic acid (GA), Folin–Ciocalteu regent, and ethanol were purchased from Merck (Merck, Darmstadt, Germany). Ultrapure water (18 Ω) and deionized water were obtained from a Milli-Q^® system (Thermo Fisher Scientific, Waltham, MA, USA).

l-α-phosphatidylcholine (PC) from egg yolk, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), and cholesterol (CH) were purchased from Sigma-Aldrich and used as supplied. The N,N,N-triethyl-N-(12-naphthoxydodecyl)ammonium surfactant (12NBr) was synthesized and characterized as reported in Reference [20 (link)]. Cefepime (see Figure 1) and chloroform (analytical grade) were from Normon (Madrid, Spain) and Merck (Mollet del Vallès, Barcelona, Spain), respectively, and used as received.
All solutions were prepared with distillated and deionized water obtained from a Millipore Milli-Q system (Fisher Scientific Company, Ottawa, ON, Canada), with a conductivity value lower than 10⁻⁶ Sm⁻¹. The pH of the solutions was maintained constant at a value of 7.4 by using a HEPES (4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid, from Sigma-Aldrich) buffer (I = 0.01 mol dm⁻³). Measurements were done at 303.0 ± 0.1K.

Fluoxetine hydrochloride (CAS# 56296-78-7), Paroxetine hydrochloride hemihydrate (CAS# 110429-35-1), Sertraline hydrochloride (CAS# 79559-97-0), dimethyl sulfoxide (CAS# 67-68-5), tricaine methanesulfonate (CAS# 886-86-2), and water (sterile filtered, Bioreagent grade) were purchased from Sigma-Aldrich Canada (Oakville, ON, Canada). Working stocks of Fluoxetine hydrochloride and Paroxetine hydrochloride hemihydrate were made by dissolving the powders in water at 10 and 5 mg/mL, respectively. Sertraline hydrochloride was dissolved in dimethyl sulfoxide (DMSO) at 10 mg/mL. These stocks were stored at 4°C. Methanol used in SSRI extractions was distilled-in-glass grade (Caledon Laboratories Ltd., Georgetown, ON, Canada). Mobile phases used in the liquid chromatography–high resolution mass spectrometry (LC-HRMS) were prepared with deionized water obtained from a Milli-Q system and LC-MS grade acetonitrile and LC-MS grade formic acid (Fisher Chemical, Ottawa, ON, Canada).