A new method for quantifying anthocyanins using ultra-high performance liquid chromatography-triple
quadrupole mass spectrometry (UHPLC-3Q-MS/MS) was developed. The method utilizes controlled
and optimized in-source fragmentation, which enables group-specific detection and
subsequent quantification of all anthocyanins derived from a single anthocyanidin
using common MRM transitions (Figure 1). The method works for a wide variety of different
sample types, including crude plant extracts, simplifying and speeding up the analysis
of anthocyanins.
Fig. 1: Anthocyanidins included in the method (A) and example MRM chromatograms combined
from two berry extracts (B).
Typical analysis methods for anthocyanins include methods based on (U)HPLC-UV/Vis
and conventional compound-specific tandem mass spectrometry. For the UV/Vis-based
methods, separation of all compounds is naturally needed, and the compound-specific
MS/MS methods require several SRM or MRM transitions to comprehensively quantify all
anthocyanins derived from one anthocyanidin aglycone. As described, the developed
method bypasses the limitations of the latter by using in-source fragmentation, and
different cone voltages are used in the method to ensure the efficient cleavage of
different types of glycones.
The method complements similar earlier analysis methods published for several other
groups of polyphenolic compounds [1,2]. These previous methods can be combined with
our new methods allowing the quantification of all major polyphenolic compound groups
in one UHPLC-3Q-MS/MS injection.
[1] Engström MT, Pälijärvi M, Fryganas C, Grabber JH, Mueller-Harvey I, Salminen JP.
J Agric Food Chem 2014; 62: 3390 – 3399
[2] Engström MT, Pälijärvi M, Salminen JP. J Agric Food Chem 2015; 63: 4068 – 4079
