Potassium carbonate

The standard of ligandrol (LGD-4033) was purchased from Toronto Research Chemicals; TRC (Toronto, ON, Canada). Stock solution of standard substance was prepared at the concentration of 1 mg/mL and its working solutions (100 µg/mL, 10 µg/mL, and 1 µg/mL) in methanol and stored at −20 °C.
Due to unavailability of certified reference materials of LGD-4033 metabolites, the reference urine collected from volunteers who ingested 50 µg of LGD-4033 dissolved in 120 mL of drinkable yogurt was utilized in the experiment [14 (link)].
LC/MS-grade of methanol and acetonitrile were purchased from MerckMillipore (Darmstadt, Germany) and Fisher Chemical (Hampton, NH, USA), respectively. Disodium phosphate and monosodium phosphate ≥ 99% purity were supplied by Honeywell (Charlotte, NC, USA), while potassium carbonate and potassium bicarbonate, both HPLC grade, were purchased at POCH S.A. (Gliwice, Poland). In turn, β-glucuronidase (Escherichia coli) and HPLC-grade methyl tert-butyl ether were supplied by Roche (Basel, Switzerland) and J.T.Baker (Philipsburg, NJ, USA), respectively. The Millipore DirectQ UV3 system (Darmstadt, Germany) was used as the source of water (R > 18 MΩ/cm). Sample preparation of dietary supplement samples followed the protocol described in [19 (link),20 (link)].

Alkyl bromides, N-methyldiethanolamine (MDEA), and methyl methacrylate (MMA) were purchased from Acros Organics (Geel, Belgium). Bisphenol A glycerolate dimethacrylate (Bis-GMA), camphorquinone (CQ), dibutyltin dilaurate (DBTDL), 2-dimethylaminoethyl methacrylate (DMAEMA), phenothiazine (PTZ), triethylene glycol dimethacrylate (TEGDMA), and tetramethylsilane (TMS) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Chloroform, methylene chloride, potassium carbonate, and toluene were purchased from POCH S.A. (Gliwice, Poland). Trimethylhexamethylene diisocyanate (TMDI) was purchased from Tokyo Chemical Industry (Tokyo, Japan). All reagents were used as received.

Alkyl bromides, MDEA, and MMA were purchased from Acros Organics (Geel, Belgium). TMDI was purchased from Tokyo Chemical Industry (Tokyo, Japan). Camphorquinone (CQ), 2-dimethylaminoethyl methacrylate (DMAEMA), phenothiazine (PTZ), and tetramethylsilane (TMS) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Dibutyltin dilaurate (DBTDL) was purchased from Fluka (Charlotte, NC, USA). Chloroform, methylene chloride, potassium carbonate, and toluene were purchased from POCH S.A. (Gliwice, Poland). All reagents were used as received.

Potassium permanganate (KMnO₄, 98%), hydrogen peroxide (H₂O₂, 35%), and ether [(C₂H₅)₂O, 99+%] were obtained from ACROS. Potassium nitrate (KNO₃, 95%), potassium carbonate (K₂CO₃, 99%), and potassium persulfate (K₂S₂O₈, 99%) were purchased from JT-Baker. Hydrochloric acid (HCl, 37%) and sulfuric acid (H₂SO₄, >95%) were purchased from Scharlau. All the chemicals were used as received. The raw MWCNTs were synthesized using a water-assisted catalytic chemical vapor deposition53 , and details are described in the supporting information. The detailed GNR synthesis process was similar to our previous work4 (link) and provided in the supporting information. In brief, MWCNTs (0.1 g) was magnetically stirred (300 rpm, 2 hrs) with a different amount of concentrated H₂SO₄ and 1 g KNO_3. Detailed conditions are summarized in Table 1. Then 0.5 g KMnO₄ was added slowly to the solution and further stirred (2 hrs, room temperature). Then the unzipping reaction was performed for 2 hrs in a water bath. Table 2 shows the detailed reaction conditions. After the reaction was completed, the product was purified and dried with a series steps reported elsewhere14 (link). The as-produced samples were characterized by various techniques including SEM, TEM, AFM, XPS, XRD, micro Raman, FTIR, and TGA. The detailed sample preparations and measurement conditions are provided in the supporting information.

All reagents were purchased from the indicated suppliers and used without further purification. Silver nitrate was purchased from Mallinckrodt (Staines-upon-Thames, United Kingdom). Trisodium citrate, potassium iodide (KI), ascorbic acid, (3-aminopropyl)trimethoxysilane (APTMS), and sodium silicate solution were purchased from Aldrich (St. Louis, MO, USA). Potassium carbonate was purchased from J. T. Baker (Phillipsburg, NJ, USA). Hydrogen tetrachloroaurate(III) hydrate was purchased from Strem (Newburyport, MA, USA). Water was purified to a resistivity of 18 MΩ.cm (Academic Milli-Q Water system; Millipore Corporation (Burlington, MA, USA)). All of the glassware used during the experiments were cleaned in a base bath, followed by aqua regia solution (3:1 HCl:HNO₃), and then dried in the oven and cooled prior to use.