Chromasolv

Hydrogen peroxide pure (Warchem, PL), with a nominal concentration 60% w/w and an actual concentration 56 ± 1% w/w, was used without purification; the concentration was determined by the standard iodometric procedure.
Phosphorus pentoxide (anhydrous, ReagentPlus^®), methanol (Chromasolv^®), n-dodecane (ReagentPlus^®), and potassium bromide (Uvasol^®) were obtained from Merck Life Science Sp.z.o.o. (PL).
Peroxides were detected in an aqueous solution using the peroxide strip test XploSens PS™ (Xplosafe LLC, USA).
Ground turmeric and sweet paprika (Kamis brand, McCormick Polska S.A., PL), ground coffee (Prima brand, Jacobs Douwe Egberts PL sp z.o.o., PL), and black tea from teabags (Minutka brand, Mokate S.A., PL) were used as obtained.

The reagents used for spectrophotometric determinations (sodium acetate, aluminum chloride, Folin–Ciocalteu phenol reagent, reagent-grade sodium carbonate, sodium acetate buffer, potassium chloride buffer) and solvents were bought from Merck (Darmstadt, Germany)
All standards and solvents were of HPLC (Chromasolv) quality and were purchased either from Sigma-Aldrich or from Merck (Darmstadt, Germany). The pure compounds used as standards were obtained from Sigma-Aldrich (Darmstadt, Germany) and the purity grade was at least 95%.

Methanol (99.9% Chromasolv) was obtained from Fluka (Sigma-Aldrich Denmark, Copenhagen, Denmark), acetonitrile (LC-MS Chromasolv) was from Riedel-de-Haën (Sigma-Aldrich Denmark, Copenhagen, Denmark) and water was Milli-Q-filtered water (Elga, Krüger Aquacare, Glostrup, Denmark). Ammonium acetate (99.999 trace metal basis), 2,5-dihydroxybenzoic acid (>99 %, matrix substance for MALDI-MS), dextran (MW ~ 6000), and polyethylene glycol 1500 were obtained from Sigma-Aldrich (Saint Louis, MO, USA).The following authentic standards were used: tetramethoxysilane, trimethoxymethylsilane, trimethoxyoctylsilane, hexamethylcyclotrisiloxane, octamethylcyclotetra- siloxane, 2-pyrrolidone, tetradecanoic acid methyl ester, pentadecanoic acid methyl ester, hexadecanoic acid methyl ester, octadecanoic acid methyl ester, tetradecanoic acid, hexadecanoic acid, and octadecanoic acid (all >99% purity; Sigma-Aldrich, Saint Louis, MO, USA). Alkyltrimethylammonium chloride with C₁₆ (>98%) and C₁₈ (>95%) alkyl chains, dimethyldialkylammonium chlorides or bromides with C₁₄ (>97%), C₁₆ (97%) and C₁₈ (>97%) alkyl chains, and benzalkonium chloride with a C₁₂ alkyl chain were also obtained from Sigma Aldrich.

OEA, PEA, the deuterated standards D₉-progesterone and D₇-cortisone, and ¹³C-labeled standards ¹³C₃-androstenedione, ¹³C₃-testosterone, and ¹³C₃-progesterone were purchased from Sigma-Aldrich (Buchs, Switzerland). ¹³C₃-cortisol and ¹³C₃-cortisone were purchased from Isoscience (Ambler, USA). AEA, 2-AG, and the deuterated eCBs (D₄-AEA, D₅-2-AG, D₄-OEA, D₄-PEA, and D₁₁-AEA) were purchased from Cayman Chemicals (Ann Arbor, USA). Water and methanol (MeOH) were of LC–MS grade (Chromasolv®) and purchased from Sigma-Aldrich (Buchs SG, Switzerland). Acetone, ethyl acetate, and ammonium fluoride were purchased from Merck (Darmstadt, Germany). Reconstitution solution consisted of 0.2 mM NH₄F in water/methanol 97/3 v/v, respectively. Isolute® SLE + columns were purchased from Biotage® (Uppsala, Sweden). All chemicals were of highest analytical grade.

Choline chloride (≥99%), lactic acid (∼90%), 1.2-propanediol (≥99%), ethanol (reagent), methanol (CHROMASOLV^®  ≥ 99.9%), water (CHROMASOLV^® Plus grade HPLC), 2,2,1-diphenyl-1-picrylhydrazyl (DPPH), 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox) gallic, ferulic, p-coumaric, sinapic and vanillic acids were obtained from Sigma-Aldrich (St. Louis, MO, USA).

For GPC,
approx. 5 mg of lignin or lignin
derivative were acetobrominated^{40 (link)} and redissolved
in tetrahydrofuran (THF) (3 mg/mL). Analysis was performed as detailed
before,^{41 (link)} omitting the determination of
correction factors. Analyses were performed using the Shimadzu hardware
components described in Method A, employing three analytical GPC columns
(each 7.5 × 30 mm) in series for analyses: Agilent PLgel 5 μm
10000 Å, followed by Agilent PLgel 5 μm 1000 Å, followed
by an Agilent PLgel 5 μm 500 Å. High-performance liquid
chromatography (HPLC)-grade THF (Chromasolv, Sigma-Aldrich) was used
as eluent (0.75 mL min^–1 for 70 min at 40 °C
column temperature). Standard calibration was performed with polystyrene
standards (Sigma-Aldrich, MW range 0.162–5000 kDa). Analyses
were run in duplicate.