Direct q 3 uv

EOZ, PhOZ, chlorobenzene,
methanol, ethanol, 37% (w/w) HCl (aq.), hexanenitrile, and hexanoic
acid were purchased from Sigma-Aldrich. The monomers and chlorobenzene
were dried over calcium hydride (CaH₂) and distilled before
polymerization. Butyronitrile and 2-chloroethylamine hydrochloride
were purchased from ABCR. Trifluoromethanesulfonic acid (TfOH) and
oxalyl chloride were purchased from Across Organics. Sodium hydroxide
(NaOH) and potassium hydroxide (KOH) were purchased from ISOLAB. ethanolamine,
CaH₂, dichloromethane (DCM), zinc acetate dihydrate (Zn(OAc)₂·2H₂O), triethylamine (TEA), and sodium sulfate
(Na₂SO₄) were purchased from Merck. PrOZ and
PeOZ monomers were synthesized following the procedures previously
reported by our group.^{36 (link)} Unless otherwise
stated, no further purification of the chemicals was performed. Deionized
water was acquired from a Merck Direct-Q-3 UV.

Acrylamide (≥99%), 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959, 98%), N,N-dimethylAcrylamide (99%), ammonium persulfate (≥98%), sodium chloride (≥99%), silicon dioxide (fine granular), lithium fluoride (powder, 300 mesh), magnesium fluoride (99.9%), sodium fluoride (99.99%), hydrochloric acid (ACS Reagent, 37%), 3-aminopropyltriethoxysilane (APTES, 99%), 3-(trimethoxysilyl)propyl acrylate (≥92%), toluene (≥99.5%), silicon oil (CAS no. 63148-62-9, viscosity 5 cSt), methacrylic acid (for synthesis) and glycerol (≥99%) were purchased from Sigma-Aldrich. Iron(iii) chloride (anhydrous, 98%) was purchased from Thermo Scientific. Magnesium oxide (99.95%) was purchased from Alfa Aesar. Fluorescein-PEG-acrylate (cat. no. FL044009-2K) was purchased from Biopharma PEG. toluene was dehydrated by 4 Å molecular sieves for 48 h before use. Deionized water (18.2 MΩ; Millipore Direct-Q 3 UV) was used in all the experiments. Laponite RD was provided by BYK Additives & Instruments. Ti₃AlC₂ MAX powder (particle size, <40 µm) was purchased from Carbon-Ukraine.

Analyses were performed for whole C. costata larvae (pools of 5 larvae taken in 4 replicates). The larvae were weighed to obtain fresh mass, plunged into LN₂, and stored at −80 °C until analysis. Frozen samples were melted on ice and homogenized in 400 μL of extraction buffer: methanol:acetonitrile:deionized water mixture (2:2:1, v/v/v). The methanol and acetonitrile (Optima™ LC/MS) were purchased from Fisher Scientific (Pardubice, Czech Republic) and the deionized water was prepared using Direct Q 3UV (Merck, Prague, Czech Republic). Internal standards, p-fluoro-DL-phenylalanine, methyl α-D-glucopyranoside (both from Sigma-Aldrich, Saint Luis, MI, USA) were added to the extraction buffer, both at a final concentration of 200 nmol.mL⁻¹. Samples were homogenized using a TissueLyser LT (Qiagen, Hilden, Germany) set to 50 Hz for 5 min (with a rotor pre-chilled to −20 °C). Homogenization and centrifugation (at 20,000× g for 5 min at 4 °C) was repeated twice and the two supernatants were combined.
In the whole-body extracts, we performed relative quantification analyses of 56 select metabolites (listed in Table S1) using the LC-HRMS platform on the Q Exactive Plus high resolution Orbitrap mass spectrometer coupled to a Dionex Ultimate 3000 liquid chromatograph and a Dionex open autosampler (all from ThermoFisher Scientific, Waltham, MA, USA). Full scan LC-HRMS positive and negative ion mass spectra were recorded in separate runs with a mass range of 70–1000 Da at 70,000 resolution (at mass m/z 200). The LC-HRMS settings were: scan rate at ±3 Hz, 3 × 106 automatic gain control (AGC) target, and maximum ion injection time (IT) 100 ms. Source ionization parameters were as follows: (±) 3000 kV spray voltage, 350 °C capillary temperature, sheath gas at 60 au, aux gas at 20 au, spare gas at 1 au, probe temperature 350 °C, and S-Lens level at 60 au. For accurate mass identification, we used lock masses of 622.0290 Da for the positive ion mode and 301.9981 Da for the negative ion mode. Chromatographic separation of metabolites was carried out on the SeQuant ZIC-pHILIC (150 mm × 4.6 mm i.d., 5 μm, Merck, Darmstadt, Germany), the mobile phase flow rate was 450 μL/min; the injection volume, 5 μL; column temperature, 35 °C. The mobile phase: A = acetonitrile (ThermoFisher Scientific, Waltham, MA, USA). B = 20 mM aqueous ammonium carbonate (pH = 9.2 adjusted by NH₄OH, Sigma-Aldrich); gradient: 0 min, 20% B; 20 min, 80% B; 20.1 min, 95% B; 23.3 min, 95% B; 23.4 min, 20% B; 30.0 min 20% B. Data were acquired and metabolites identified using an in-house Metabolite Mapper platform equipped with an internal metabolite database in conjunction with Xcalibur™ software (v2.1, ThermoFisher Scientific, Waltham, MA, USA). All 56 metabolites were quantified relatively using the areas under respective chromatographic peaks normalized to fresh mass of larval samples.

After 5 days treatment with 0 (control) or 100 μM Cd, Salvia plants were harvested, separated in roots and aboveground (shoots-leaves) tissues, washed three times in deionized water, and then dried at 65 °C to constant biomass, milled and finally sieved. Dried sieved samples of 0.3 g were transferred in 10 mL quartz vessels with 65% (v/v) nitric acid (Suprapur, Merck, Darmstadt, Germany) and 30% (v/v) hydrogen peroxide (Suprapur, Merck, Darmstadt, Germany) in 3:1 ratio. Digestion was carried out in the microwave assisted digestion system Ethos One (Milestone Srl, Sorisole, BG, Italy). The process run out in 3 stages: ramp time—20 min to reach 200 °C and 1500 W; hold time—30 min at 200 °C and 1500 W; cooling—30 min. The next step was the quantitative transfer of digested samples into polypropylene tubes and dilution with demineralized water (Direct-Q 3 UV, Merck, Darmstadt, Germany). All prepared samples were diluted immediately prior to inductively coupled plasma mass spectrometer (ICP-MS) analysis. Samples were analyzed in an ICP-MS model ELAN DRC II (PerkinElmer Sciex, Toronto, Canada) [127 (link)]. ICP-MS operational conditions, instrumental settings calibration solutions, data validation, and validation parameters are given in Appendix A. Elemental analysis was performed for Cd, Cu, Ca, Mg, Mn, Fe, and Zn.

All solutions used in this work were prepared by utilization of an ultra-pure water purification system from Millipore: Direct-Q3 UV with 18.2 MΩ cm water resistivity. Supporting solutions of 0.1 M NaOH and 0.5 M Na₂SO₄ were made up from Merck 99.99% NaOH pellets and Merck 99.99% Na₂SO₄ pellets, respectively. Additionally, 0.5 M H₂SO₄ solution was prepared from sulphuric acid (SEASTAR Chemicals, Sidney, BC, Canada) to charge a Pd reversible hydrogen electrode (RHE). The resorcinol concentration (Sigma-Aldrich (Saint Louis, MO, USA), >99%) was on the order of 1 × 10⁻³ M.
Two types of electrochemical cells were used during the course of this work. Hence, all kinetic investigations were carried out with a typical, three-compartment Pyrex glass made electrochemical cell, whereas a single-cell electrolyzer unit was employed to perform continuous (8-h long) galvanostatic/potentiostatic resorcinol oxidation tests. Both cells contained three electrodes: a Ni foam-based working electrode (WE), the RHE as reference, and a counter electrode (CE) made from a coiled Pt wire (1.0 mm diameter, 99.9998% purity, Johnson Matthey, Inc., Audubon, PA, USA) and stainless steel, correspondingly.
Nickel foam was delivered by MTI Corporation (purity: >99.99% Ni; thickness: 1.6 mm; surface density: 346 g m⁻²; porosity: ≥95%). Examined electrodes were in two sizes, namely: 1 × 1 cm and 5 × 5 cm (continuous, 8-h long electrolysis trials). Information on the preparation of working electrodes (including Pd catalyst modification) and on all pre-treatments was given in Reference [12 (link)]. Nevertheless, it should be stated that for a 1 × 1 cm nickel foam electrode (ca. 33.4 mg mass), the electrochemically active surface area was roughly estimated (based on the a.c. impedance-derived double-layer capacitance parameter) in Reference [12 (link)] at 13.9 cm². However, as it is very difficult to quantitatively determine the surface area of such a porous entity as a Ni foam electrode, it is, therefore, quite convenient to present the recorded electrochemical results as per the electrode mass. In this work, average values of Ni foam electrode mass were estimated at: 35.8 mg (1 × 1 cm) and 894.2 mg (5 × 5 cm).
All electrochemical measurements were conducted at room temperature by means of the Solartron 12,608 W Full Electrochemical System, containing a 1260 frequency response analyzer (FRA) and 1287 electrochemical interface (EI) units. Electrochemical impedance spectroscopy and cyclic voltammetry, as well as continuous, 8-h long galvanostatic/potentiostatic resorcinol electrodegradation experiments, were carried out in this work. For a.c. impedance measurements, the generator provided an output signal of 5 mV and the frequency range was swept between 1.0 × 10⁵ and 0.5 × 10⁻¹ Hz. The instruments were controlled by ZPlot 2.9 or Corrware 2.9 software for Windows (Scribner Associates, Inc., Southern Pines, NC, USA). Usually, three impedance measurements were independently conducted at each potential value on two Ni foam electrodes. Reproducibility of the thus-obtained results was typically below 10%. Data analysis was performed with ZView 2.9 (Corrview 2.9) software package, where the impedance spectra were fitted by means of a complex, non-linear, least-squares immittance fitting program, LEVM 6, written by J.R. Macdonald [13 ].
Furthermore, selected pre-electrolyzed wastewater samples were subjected to a quantitative assessment of the reaction products/intermediates by means of the combined HPLC/MS analysis. Hence, the analyses were conducted by means of HPLC (LC 20 Prominence, Shimadzu, Japan) system combined with QTRAP 5500 mass spectrometer (AB SCIEX, Concord, ON, Canada), equipped with an ESI ion source, triple quadrupole and an ionic trap. Reaction products were separated by means of XBridge C18 (3.5 µm, 150 × 2.1 mm) chromatographic column (Waters, Milford, MA, USA) at 45 °C for the mobile phase flow of 0.2 mL min⁻¹. Both qualitative and quantitative analyses were conducted based on the MRM (Multiple Reaction Monitoring) method. The quantitative analysis was performed through the application of linear calibration curves (R² = 0.993), based on a series of dilutions of external standards. In addition, comparative determination of resorcinol was also carried out based on the bromometric titration method [14 ,15 ].
On the other hand, spectroscopic characterization of pure and Pd-modified Ni foam electrodes, before and after resorcinol electrooxidation trials, was performed by means of Quanta FEG 250 Scanning Electron Microscope (SEM), equipped with an Energy-Dispersive X-ray Spectroscopy (EDX) supplement (Bruker XFlash 5010). EDX tests were carried out at an acceleration voltage of 12 kV with a primary intention to confirm the presence of resorcinol polymer on the surface of the examined Ni foam electrodes.