Ammonium chloride

Natural graphite powder (CFW-18AK, 18 μm nominal particle size), and UF resin were provided by Chuetsu Graphite Works (Osaka, Japan), and DIC Kitanihon Polymer (Tomakomai, Japan), respectively. According to the manufacturer, the resin has the following general physicochemical properties: 51% non-volatile solids content, 7.5 pH, 110 mPa s viscosity, and 1.2 formaldehyde/urea molar ratio. Ammonium chloride (99.5% purity), which is a curing agent, was purchased from Kanto Chemical (Tokyo, Japan). Citric acid (>99.5% purity), and calcium hydroxide (>96.0% purity) as a pH adjuster were purchased from Wako Pure Chemical Industries (Osaka, Japan), and Kanto Chemical, respectively. Sulfuric acid (96.0% concentration), potassium permanganate (99.3% purity), and hydrogen peroxide solution (34.5% concentration) for GO preparation were purchased from Kanto Chemical. All reagents were used as received without further purification.

2,2’-Dipyridyl disulfate, 4-nitro-7-piperazino-2,1,3-benzoxadiazole, 5,6-diamino-2,4-hydroxypyrimidine sulfate, pentobarbital sodium, and triphenyl phosphine were purchased from Tokyo Kasei Kogyo (Tokyo, Japan). Ammonia was obtained from Showa Chemical (Tokyo, Japan), and ammonium chloride was purchased from Kanto Chemical (Tokyo, Japan). A bicinchonic acid (BCA) Protein Assay kit was obtained from Thermo Fisher Scientific (Waltham, USA). Citric acid monohydrate and sodium hydroxide were purchased from Nacalai Tesque (Kyoto, Japan). Lithium D-lactate, lithium L-lactate, paraformaldehyde, and methylglyoxal were obtained from Sigma Chemical (St. Louis, USA). High-performance liquid chromatography (HPLC)-grade acetonitrile was obtained from Merck (Darmstade, Germany). HPLC-grade methanol and propionic acid were purchased from Mallinckrodt Baker (Phillipsburg, USA). Saikosaponin C was obtained from Wako Pure Chemical (Osaka, Japan). Triflouroacetic acid was purchased from Riedel-de Haën (Seelze, Germany).

Irgafos 168 and Erucamide were purchased from Tokyo Chemical Industry Co. (Tokyo, Japan). Acetone, methanol, chloroform, sodium chloride, potassium chloride, sodium sulfate, ammonium chloride, urea, lactic acid, sodium hydroxide, and 2-propanol were purchased from Kanto Chemical Co. (Tokyo, Japan). Formic acid was purchased from Fluka (Charlotte, NC, USA). Water was generated by PURELAB frex-3 (ELGA, High Wycombe, UK). These reagents were used without further purification. Stock solutions of Irgafos 168 and Erucamide were prepared by dissolving 0.1 g of reagents in 100 mL of Acetone and methanol, respectively. Working solutions were prepared by diluting the stock solutions with methanol.