Dietary Phenolic Compounds in Biological Samples: Current Challenges in Analytical Chemistry

Abstract

Phenolic compounds are bioactive molecules relevant in plant-derived foods and are associated with beneficial health effects in humans. The metabolism of these phytonutrients comprises of the absorption, distribution, metabolism, and excretion and is investigated in in vivo intervention or in vitro cell culture studies. Blood and urine samples are collected during animal or human trials, and matrix effects caused by high protein and salt concentration are a major challenge during analysis. This chapter describes the context between the matrix effects which arise during phenolic compound analysis from biological samples and possible analytical techniques to handle these challenges. Difficulties arise from interfering matrix compounds, low concentrations of chemically heterogeneous metabolites, and the lack of reference compounds. Therefore, interactions of phenolic compounds with plasma proteins are reviewed, as well as ion suppression as one of the most common matrix effects during LC-MS analysis. Frequently used analytical techniques for sample preparation, compound synthesis, separation, and detection are described in this chapter.