Detection, characterization and identification of phenolic acids in Danshen using high-performance liquid chromatography with diode array detection and electrospray ionization mass spectrometry

By using HPLC-diode array detection-electrospray ion trap tandem mass spectrometry (HPLC-DAD–ESI-MSn) in negative ion mode, we have analyzed the fragmentation pathways of 11 phenolic acids which were isolated from Danshen. Then the extract of Danshen was analyzed, and a total of 42 phenolic acids, including sixteen new minor constituents, were identified or tentatively identified for the first time. A new solid-phase extraction (SPE) method, new HPLC separation method, new liquid chromatography (LC)–MS and LC–MSn (n = 3–5) data and proposed fragmentation pathways, LC retention time for phenolic acids are reported.