Integral 5 water purification system

Potassium hexacyanoferrate (II) trihydrate (98%, Carrez-I) and zinc acetate dehydrate (>99%, Carrez-II) were obtained from Sigma (St. Louis, USA). 13C3-labelled acrylamide (99% isotopic purity) was obtained from Cambridge Isotope Laboratories (Andover, MA, USA). HMF was purchased from Sigma (St. Louis, MO, USA). Formic acid (98%) was obtained from Panreac (Barcelona, Spain). Deionized water was obtained from a Milli-Q Integral 5 water purification system (Millipore, Billerica, MA, USA). Reversed-phase Oasis-HLB cartridges (30 mg, 1 mL) were provided by Waters (Milford, MA, USA). High performance liquid chromatography (HPLC)-grade methanol was obtained from Merck (Darmstadt, Germany). All other chemicals, solvents and reagents were of analytical grade.

In total, 92 ginsenosides were used as reference standards, which were either purchased from Shanghai Standard Biotech. Co., LTD. (Shanghai, China) or isolated by the authors from the P. ginseng and P. notoginseng roots. The chemical structures of these compounds and detailed information are shown in Fig. 2 and Additional file 1: Table S1. The raw materials of PJM were purchased from Hanzhong (Shaanxi, China), and authenticated by Prof. Xian-kuan Li (Tianjin University of Tradition Chinese Medicine). The voucher specimens were deposited at the authors’ laboratory in Tianjin University of Traditional Chinese Medicine (Tianjin, China). Both acetonitrile and formic acid (Fisher, Fair Lawn, NJ, USA) were the LC–MS grade. Ultra-pure water (18.2 MΩ·cm at 25 °C) was in-house prepared using a Milli-Q Integral 5 water purification system (Millipore, Bedford, MA, USA).
Fig. 2

Chemical structures for 92 ginsenoside reference standards

All experiments involving the use of radioactive materials at Washington University are conducted under the authorization of the Radiation Safety Committee in accordance with the University's Nuclear Regulatory Commission license. Activity was determined with a Capintec CRC-25 Dose Calibrator calibrated to a factor of 465 for ⁸⁹Zr (Capintec, Ramsey, NJ). All chemicals were purchased from Sigma-Aldrich (St. Louis, MO), unless otherwise specified, and all solutions were prepared using ultrapure water with an 18 MΩ-cm resistivity produced by a Millipore Integral 5 water purification system (Millipore, Billerica, MA).