Submitted to: Rapid Communications in Mass Spectrometry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/27/2012
Publication Date: 2/27/2012
Citation: Sun, J., Lin, L., Chen, P. 2012. Study of the mass spectroscopic behaviors of anthocyanins in negative ionization mode and its applications for fast differentiation of anthocyanins and non-anthocyanin polyphenols in natural products. Rapid Communications in Mass Spectrometry. 26:-1123-1132. Interpretive Summary: The mass spectrometry (MS) behaviors of anthocynanins in positive ion mode have been well studied. However, the study of anthocyanins in negative ion mode MS has not been reported. This paper describes a newly developed strategy primarily based on the mass spectrometric behavior of anthocyanin in negative ionization mode. Compared to positive ion mode MS study, the new strategy gives a different set of ions that can be used for identification and differentiation of anthocyanin and non-anthocyanin phenolic compounds. The new strategy has been applied to the differentiation of anthocyanins and flavonol glycosides in blueberry, Brassica compestris L. var. purpurea Bailey, and red radish. The data generated from a single LC run can rapidly and reliably differentiate and identify anthocyanin and non-anthocyanin phenolic compounds.
Technical Abstract: A study of the mass spectroscopic behaviors of anthocyanins in the negative ionization mode was reported and it can be used for differentiation anthocyanins from other non-anthocyanin polyphenols. For the study, an ultra-high performance liquid chromatography with high resolution mass spectrometry (U-HPLC-HRMS) method was developed. Traditionally, anthocyanin analysis in mass spectrometry is carried out in the positive ionization mode only. The new strategy found , in the negative ionization mode, a series of characteristic ions, e.g. [M-2H]-, [M-2H+H2O]- , formic acid adducts, and double charged ions were observed for the MS analysis of anthocyanins. The characteristic ions can be used for identification and differentiation of anthocyanins and non-anthocyanin phenolic compounds. Comprehensive studies were performed on the differentiation of anthocyanins and non-anthocyanin polyphenols in blue berry, Brassica compestris L. var. purpurea Bailey, and red radish. Tentative identification of these phenolic compounds was made by accurate mass measurement with <3 ppm accurarcy and multiple-stage mass fragmentation data in both the negative and positive ion in one single LC run. The whole cycle time of the new method is 1.8 sec for 2 full scans and 6 data-dependent scans. The data generated from a single LC run enables rapid and reliable differentiation and identification of anthocyanins and non-anthocyanins in botanicals and foods.