B American Society for Mass Spectrometry, 2018 J. Am. Soc. Mass Spectrom. (2018) 29:1594Y1600
Ambient Profiling of Phenolic Content in Tea
Infusions by Matrix-Assisted Ionization in Vacuum
Robert B. Cody
JEOL USA, Inc., 11 Dearborn Road, Peabody, MA 01960, USA
Abstract. Matrix-assisted ionization in vacuum
(MAIV) was used to analyze the polyphenol con-
tent of ten different tea infusions. Nine different
Camellia sinensis infusions were analyzed in-
cluding three green teas, two black teas, two
oolong teas, jasmine tea, and white tea. An infu-
sion of rooibos (Aspalathus linearis) tea was also
analyzed. Each freshly brewed tea was diluted
1:1 with methanol, and 100 ppm of phenolphtha-
lein was added as an internal standard. An ex-
cess of 3-nitrobenzonitrile (NBN) was added to each vial, and the solution containing NBN crystals was analyzed
by aspiration directly into the mass spectrometer sampling orifice. A working curve constructed for dilutions of
catechin with phenolphthalein internal standard showed good linearity for five replicates of each concentration.
The measured relative abundances of flavonoid polyphenols in each tea were in good agreement with previously
reported values. Polyphenol content in tea infusions varied from 19.2 to 108.6 mg 100 mL
. In addition to the
expected catechin flavonoids, abundant quinic acid and gallic acid was detected in the C. sinensis infusions.
Characteristic A. linearis flavonoids were detected in the rooibos tea.
Keywords: Ambient ionization, Tea, Camellia sinensis, Matrix-assisted ionization in vacuum, Polyphenols,
Received: 18 May 2017/Revised: 4 May 2018/Accepted: 4 May 2018/Published Online: 29 May 2018
ith the exception of water, tea is the most widely con-
sumed beverage in the world. Infusions of Camellia
sinensis leaves are the most familiar form of tea, although other
many other plants can be used to prepare a beverage.
C. sinensis polyphenols are of interest because of potential
health benefits. Epigallocatechin gallate (EGCG) has antioxi-
dant properties and may also have chemoproventive,
antiinfective, and cardiovascular properties [1–4]. Other poly-
phenols in C. sinensis tea may have beneficial properties. For
example, quinic acid has been proposed as a candidate for
treating prostate cancer . Aspalathus linearis (rooibos tea)
polyphenols may have similar properties [6–9]. Because of
these potential benefits, the chemical analysis of tea has been
the subject of numerous chromatographic studies, as detailed in
a recent review .
C. sinensis tea is categorized by the degree of fermentation.
In order of increasing fermentation, the most common varieties
are white, green, oolong, and black tea. Matcha refers to finely
powdered green tea made from the deveined leaves of shade-
grown tea. Jasmine tea is green tea with dried jasmine (Genus
Jasminium) leaves added for fragrance. Rooibos (Bred bush^)
tea is made from leaves of A. linearis with a very different
phenolic composition than C. sinensis tea.
Analysis of tea products by ambient ionization  has been
reported in only a few instances. Direct Analysis in Real Time
(DART)  was used to profile selected catechin polyphenols
in green tea, black tea, oolong tea, and a nutraceutical tea
extract. Because thermal degradation of flavonoid glycosides
such as catechin gallates can occur during DART analysis,
detection of these important compounds required derivatization
 and the derivatized compounds were detected in positive-
ion mode. Fraser and coworkers reported on the use of DART
Electronic supplementary material The online version of this article (https://
doi.org/10.1007/s13361-018-1990-2) contains supplementary material, which
is available to authorized users.
Correspondence to: Robert Cody; e-mail: email@example.com