High performance liquid chromatography grade methanol

The standard chemicals for untargeted and targeted profiling were obtained from Steraloids (Newport, RI, USA); Cayman Chemical (Ann Arbor, MI, USA); Tokyo Chemical Industry (Tokyo, Japan); and Sigma-Aldrich (St. Louis, MO, USA). Formic acid, sodium acetate, and acetic acid were obtained from Sigma-Aldrich. The enzyme hydrolysis solution, β-glucuronidase/arylsulfatase extracted from Helix pomatia, was obtained from Roche (Mannheim, Germany). Derivatization agents 2-hydrazinopyridine, triphenylphosphine, 2,2′-dipyridyl disulfide, and dansyl chloride were purchased from Sigma-Aldrich and Tokyo Chemical Industry. High-performance liquid chromatography-grade methanol, acetonitrile, ethyl acetate, methyl tert-butyl ether, and hexane were purchased from Burdick & Jackson (Muskegon, MI, USA). Deionized water was prepared using a Milli-Q purification system from Millipore (Bedford, MA, USA). Oasis HLB cartridge (3 mL, 60 mg) was purchased from Waters (Milford, MA, USA).