Direct q3 uv system

Acetonitrile and formic acid of ULC/MS grade were from Bio-Lab (Israel). Water with resistivity 18.2 MΩ was obtained using Direct 3-Q UV system (Millipore). N-acetylneuraminic acid standard (NANA) was purchased from Biosynth-Carbosynth. ¹³C₃-N-acetylneuraminic acid (¹³C₃-NANA) from Omicron Biochemicals was used as internal standard.

Deuterated internal standards (ISs) D₄-Cort, D₈-21Deox, D₂-11Deox, D₅-4AD and D₈-17OHP were purchased from Cambridge Isotope Laboratories (Andover, MA, USA); unlabeled Cort, 21Deox, 11Deox, 4AD and 17OHP from Sigma-Aldrich (St. Louis, MO, USA); methanol (LC-MS grade) and formic acid (LC-MS grade) from Honeywell (Charlotte, NC, USA); and acetonitrile (LC-MS grade) from Merck (Darmstadt, Germany). Ultrapure water (18.2 MΩ.cm), filtered through a 0.22 μm pore size membrane, was obtained from a Merck Millipore Direct-Q 3 UV system (Billerica, MA, USA).

All reagents were of analytical quality. Ultrapure (Milli-Q) water (18.2 MΩ cm) from a Direct-Q 3 UV system (Merck Millipore, Darmstadt, Germany) was used for all steps of sample preparation and analysis. Conc. HNO₃ was purchased from Merck (Darmstadt, Germany). A citrate buffer solution (CBS) was prepared as previously described [46 (link)].
Working standards for fluoride (F^–) were prepared from a (100.0 ± 0.5) mg/L-certified standard solution (Thermo Fisher Scientific, Waltham, MA, USA). A Merck-IV-certified ICP multi-element standard solution ((1001 ± 10) mg/L, aluminium) was used to prepare working standards for aluminium (Al). A 0.050 mol/L working solution of sodium fluoride was prepared by dissolving NaF (Merck) in water.
The accuracy of the calibration curve for F^– was checked with another certified F^– standard solution and for Al with an Inorganic Ventures certified-quality standard IV-ICPMS-71A ((10.01 ± 0.04) mg/L, aluminium) (Christiansburg, VA, USA).
Samples were weighed into brown tea filter Cilia size M (Melitta, Minden, Germany). The 0.45 µm polytetrafluoroethylene hydrophobic membrane filters (25 mm diameter) from Machery Nagel (Dueren, Germany) were used for filtration with a 10 mL syringe Chirana (Stará Turá, Slovakia).

The chemicals used were deionized water (from Direct-Q3 UV system, Merck Millipore, Burlington, MA, USA); methanol (for LC-MS, VWR, Střibrná Skalice, Czech Republic); EDTA disodium salt (G.R., Lach-Ner, Neratovice, Czech Republic); hydrochloric acid (p.a., Penta, Chrudim, Czech Republic) and standards of ampicillin, chloramphenicol, clindamycin hydrochloride, erythromycin, linezolid, tetracycline, vancomycin hydrochloride (Spinchem, Plzen, Czech Republic), nitrofurantoin, teicoplanin A2 (mixture of A2-1–A2-5), tigecycline, ampicillin-d5, clindamycin-d3, chloramphenicol-d5, erythromycin-13C,d3, linezolid-d3, nitrofurantoin-13C3, tetracycline-d6 and tigecycline-d9 (LGC standards, Lomianki, Poland).

All solid reagents were of analytical grade and were used without further purification. Ethanol, HAuCl₄, and sulfate acid were obtained from Beijing Chemical Works (Beijing, China). NaCl and KNO₃ were obtained from Sinopharm Chemical Reagent Co. Ltd. (Shanghai, China). PdCl₂ was obtained from Sigma-Aldrich (Saint Louis, MO, USA). Water used in the experiment was all deionized water with a resistivity of 18 MΩ·cm obtained from Millipore Direct-Q 3 UV system (Merck Millipore Co., Billerica, MA, USA).

ONC201 dihydrochloride (DiHCl) (batch #S22S02C27; purity > 99%) was purchased from MedKoo Biosciences (Morrisville, NC, USA). Analytical grade acetonitrile was obtained from Sigma-Aldrich (St Quentin-Fallavier, France). Ultrapure water was produced by the Direct-Q^® 3 UV system (Merck, Guyancourt, France). Hydrogen peroxide (H₂O₂) 30% v/v was supplied by Carlo Erba SDS (Val de Reuil, France), whereas hydrochloric acid and sodium hydroxide were obtained from Sigma-Aldrich (St Quentin-Fallavier, France).
The antioxidant agents used were ascorbic acid, N-acetyl cysteine, and sodium sulfite. The latter were supplied by Sigma-Aldrich (St Quentin-Fallavier, France).

Non-aligned bast fibers from hemp (Cannabis sativa L.) plants of the Carmagnola variety, harvested at seed maturity, non-retted, and mechanically decorticated in a “disordered line”, were supplied by Assocanapa (Carmagnola, Italy). The fibers were cleaned and disentangled with a Mixicomber machine (O. M. Alvaro Mason & C S.N.C., Valle Mosso, Italy) prior to use.
The chemicals used for the pretreatment were sodium hydroxide pellets (Carlo Erba Reagents S.A.S., Val de Reuil, France) and hydrochloric acid, 37% (Sigma-Aldrich, Inc., St. Louis, MO, USA); ultrapure water from a Millipore Direct-Q 3 UV system (Merck KGaA, Darmstadt, Germany) was used to dilute them to the desired concentrations. For the enzymatic treatment, a buffer was prepared using acetic acid ≥99.7% and sodium acetate trihydrate ≥99.0% (Sigma-Aldrich, Inc., St. Louis, MO, USA); the enzyme was FiberCare^® R cellulase 4890 ECU (Novozymes, Copenhagen, Denmark).