Analysis of ellagitannins and conjugates of ellagic acid and quercetin in raspberry fruits by LC–MSn

Identification of phenolic compounds in strawberries by liquid chromatography electrospray ionization mass spectroscopy

“…Peak 17 was identified as sanguiin H-6 (MS m/z = 1869; MS/ MS m/z = 1567, 1265,935,633,301,257,229) (Fig. 1) by comparison of its LC-MS/MS data with literature reports (Maatta-Riihinen et al, 2004;Mullen et al, 2003).…”

“…Zoom scan analyses were carried out to determine the charge state of some of the ellagitannin-based compounds. Identities of the compounds were obtained by matching their molecular ions (m/z) obtained by LC-ESI-MS and LC-ESI-MS/MS with literature data (Lopes-da-Silva et al, 2002;MaattaRiihinen et al, 2004;Mullen et al, 2003).…”

“…LC-MS/MS methods were also used to distinguish between conjugates of quercetin and EA since their aglycons produce identical molecular ions on fragmentation (M À H + , m/z 301) (Mullen et al, 2003). On MS/MS analyses, the quercetin m/z 301 ion further fragments to form characteristic m/z 179 and 151 ions (Fig.…”

“…This technique improves resolution of the 12 C/ 13 C isotopes of compounds, allowing their charge state to be determined and hence facilitating the correct determination of their molecular weights (MW) (Mullen et al, 2003). Therefore, peak 17 had a (M À H + ) ion at m/z 934, which was shown to be doubly charged by zoom-scan analysis (Fig.…”

“…On the other hand, the use of HPLC with mass spectrometry (HPLC-MS) detection provides useful structural information and allows for tentative compound identification when standard reference compounds are unavailable and when peaks have similar t R and similar UV-absorption spectra (Hakkinen, Karenlampi, Heinonen, Mykkanen, & Torronen, 1999;Lopes-da-Silva et al, 2002;Maatta-Riihinen, Kamal-Elin, & Torronen, 2004). In addition, tandem mass spectrometric (MS n ) techniques are useful for distinguishing compounds with identical molecular weights (Mullen, Yokota, Lean, & Crozier, 2003).…”