Determination of polyphenolic compounds by liquid chromatography–mass spectrometry in Thymus species

Simultaneous determination of caffeic acid phenethyl ester and its metabolite caffeic acid in dog plasma using liquid chromatography tandem mass spectrometry

“…Moreover, a variety of methods has been established to identity or quantify CA in various matrices including plant tissues [38][39][40][41], rat plasma [42,43], human plasma [44,45] and human serum [46]. Those methods involved high performance liquid chromatography coupled with electrochemical detector [47][48][49], HPLC-UV [50], gas chromatography coupled with mass spectrometry [51], LC-MS [39,40] and LC-MS/MS [41,[43][44][45]. Nevertheless, no study has reported a method for the simultaneous determination of CAPE and CA in biological matrices.…”

Challenges in Separations of Proteins and Small Biomolecules and the Role of Modern Mass Spectroscopy Tools for Solving Them, as Well as Bypassing Them, in Structural Analytical Studies of Complex Biomolecular Mixtures

“…While the LC-MS approach does simplify identification of polyphenols significantly, due to the efficient separation of various classes of polyphenol structural isomers, it often requires purified standards for assigning R t values to specific polyphenol structures, and these are not readily available, especially when novel polyphenols or their derivatives are detected in various plant/food samples. Thus, while the LC-MS approach excels in partial characterization of complex polyphenol mixtures [2,[64][65][66], full characterization of all polyphenols and their derivatives detected using MS alone has not yet been attempted, unless simpler mixtures were analyzed. In order to achieve that, appropriate intra-laboratory databases have to be constructed [67], which requires focus on one sample/plant type, respective standards and literature data.…”

“…Thus the polyphenol standards are still widely used for both qualitative [64] and quantitative [65] analyses. In Figure 20, LC-MS chromatograms of standards for 15 phenolic compounds are shown [64]. These can subsequently be used for the creation of an Rt, m/z database, confirmation of MS data, as well as for subsequent MS/MS experiments.…”

“…This is particularly true since the main role of LC is separation of stereoisomers, as well as their identification based on R t values, determined with the help of available standards. Thus the polyphenol standards are still widely used for both qualitative [64] and quantitative [65] analyses. In Figure 20, LC-MS chromatograms of standards for 15 phenolic compounds are shown [64].…”

“…Phenolic compounds include various plant metabolite structures, ranging from simple phenolic acids and phenyl alcohols, to very complex tannin structures [2,64]. Polyphenols represent one of the least favorable classes of biomolecules for structural MS analysis.…”