Performance of 3‑[4‑(bromomethyl)phenyl]‑7‑(diethylamino) coumarin as a derivatization reagent for the analysis of medium and long chain fatty acids using HPLC with LIF detection.

Knowledge of the profile of fatty acids, including the profile of long chain fatty acids, is an important parameter for many areas like human health, food sciences, and the study of gene expression in plant tissues, among others. Moreover, very long chain fatty acids occur at low concentrations in many biological samples. The 3‑[4‑(bromomethyl)phenyl]‑7‑(diethylamino)coumarin (MPAC‑Br) reagent is an improved version of the coumarin bromomethyl-type reagents, used for the fluorescent labeling of carboxylic acids in a variety of sample types. Derivatization reactions are always a matter of concern in routine analyses, as they are seen as a time demanding step and a source of errors in analytical chemistry. MPAC‑Br is studied in the present work, including the robustness of its derivatization reaction, the stability of its derivatives, the limits of its detection and the repeatability of its results. An optimized version of its protocol was applied to determine the content and profiles of both medium and long chain fatty acids in eight samples of oils and fats. It was shown that the proposed derivatization reaction is a reliable, robust, fast and convenient method for the analysis of these compounds.