2.1. Reagents and Standards

Analytical reference standards for identity confirmation were supplied, as specified in Section 1 of the Supplementary Materials. Hydrochloric acid (37%), LC-MS grade methanol and water were obtained from J.T. Baker (Deventer, the Netherlands). HPLC grade acetone, glacial acetic acid and LC-MS formic acid were purchased from Sigma-Aldrich (St. Louis, MO, USA). Sodium fluoride, Folin–Ciocalteu reagent and sodium carbonate were obtained by Merck (Darmstadt, Germany). Ultrapure water was taken from a Milli-Q system (Millipore, Billerica, MA, USA). Nylon membranes (porosity 0.2 μm) for the filtration of raspberry extracts before HPLC analysis were obtained from VWR™ International (Radnor, PA, USA).