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United States Department of Agriculture

Agricultural Research Service

Research Project: FINGERPRINTING AND PROFILING METHODS FOR CHARACTERIZATION OF FOODS AND DIETARY SUPPLEMENTS Title: A flow-injection mass spectrometry fingerprinting method for authentication and quality assessment of Scutellaria lateriflora-based dietary supplements

Authors
item Sun, Jianghao -
item Long-Ze, Lin -
item Chen, Pei

Submitted to: Analytical and Bioanalytical Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 6, 2011
Publication Date: July 21, 2011
Citation: Sun, J., Long-Ze, L., Chen, P. 2011. A flow-injection mass spectrometry fingerprinting method for authentication and quality assessment of Scutellaria lateriflora-based dietary supplements. Analytical and Bioanalytical Chemistry. 401:1577-1584.

Interpretive Summary: Identification and differentiation of anthocyanins and non-anthocyanin compounds in natural products can be very difficult. Anthocyanin analysis using mass spectrometry (MS) is carried out in a positive mode since anthocyanins are positively charged. In the positive mode, MS cannot differentiate anthocyanins and non-anthocyanin phenolic compounds. Traditionally, an ultra-violet/visible detector is used. However, it suffers from low sensitivity and poor specificity. The newly developed strategy is primarily based on the mass spectrometric behavior of anthocyanins in negative ionization mode in which a series of characteristic ions, e.g. [M-2H]-, [M-2H+H2O]- , formic acid adducts, and double charged ions for anthocyanins can be observed. For non-anthocyanin phenolic compounds, usually only the [M-H]- ion is observed. Thus, 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 flavonol glycosides in blueberry, Brassica compestris L. var. purpurea Bailey, and red radish. The data generated from a single LC run proved to be able to rapidly and reliably differentiate and identify anthocyanins and non-anthocyanin phenolic compounds.

Technical Abstract: Identification and differentiation of anthocyanins and non-anthocyanin compounds in natural products can be very difficult by mass spectrometry. Using a ultra-violet/visible detector can be helpful, but not fool-proof, and it requires an additional detector. To solve the problem, a fast and reliable method was developed using an ultra performance liquid chromatography tandem with high resolution mass spectrometry (UPLC-HRMS). Traditionally, anthocyanin analysis in mass spectrometry is carried out in positive mode. The new strategy is primarily based on the mass spectrometric behavior of anthocyanin in negative ionization mode in which a series of characteristic ions, e.g., [M-2H]-, [M-2H+H2O]-, formic acid adducts, and doubly charged ions could be observed. 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 flavonol glycosides in blueberry, Brassica compestris L. var. purpurea Bailey, and red radish. Tentative identification for these phenolic compounds was made by accurate mass measurement with <3 ppm accuracy and multiple-stage mass fragmentation data in both negative and positive ion modes. The whole cycle time of the new method was 1.8 sec for 2 full scans and 6 data-dependent scans. The data generated from a single LC run enabled rapid and reliable differentiation and identification of anthocyanins and non-anthocyanin phenolic compounds in botanicals and in foods.

Last Modified: 10/30/2014