Ficoll paque solution

DL-homocysteine, L-methionine, trichloroacetic acid (TCA), 2′,7′-dichlorofluorescein diacetate (DCFH-DA) were purchased from Sigma-Aldrich (St. Louis, MO, USA). DL-homocysteine-3,3,4,4-d4 (homocysteine-d4) was obtained from CDN Isotopes Inc. (Quebec, Canada). L-homocysteine was from Bide Pharmatech Ltd. (Shanghai, China). Hydrogen peroxide (30%), LC-MS grade acetonitrile, and methanol were from Merck (Germany). Catalase was purchased from Worthington Biochemical Corporation (NJ, USA). 2-chloroquinoline, trimethyloxonium tetrafluoroborate, and formic acid were purchased from Aladdin (Shanghai, China). Tris-(2-carboxyethyl) phosphine hydrochloride (TCEP) was purchased from Energy Chemical (Shanghai, China). Glutathione was obtained from Generay Biotech Co. Ltd. (Shanghai, China), and 2-chloro-1-methylquinolinium tetrafluoroborate (CMQT) was synthesized according to the literature [20 (link)]. Rosup (a chemical mixture including 4-Butylhydroperoxide, 50 mg/mL in DMSO, catalog S0033S-2) was purchased from Beyotime Biotechnology (Shanghai, China). The Methemoglobin Assay Kit was purchased from Nanjing Jiancheng Bioengineering Institute (Nanjing, China). The bovine hemoglobin and Ficoll-Paque solution were from Beijing Solarbio Science and Technology Co. Ltd. (Beijing, China).