4-Bromomethyl-7-methoxycoumarin and analogues as derivatization agents for high-performance liquid chromatography determinations: a review

A major part of modern analytical problem solving deals with the trace level determination of organic compounds and contaminants in biomedical, food and environmental samples. In the analysis of these samples chromatographic techniques play a predominant role. Unfortunately, however, even the combined force of an efficient separation plus a sophisticated mode of detection does not always create sufficient selectivity and/or sensitivity for the final goal to be attained. In such cases, special attention has to be devoted to derivatization or conversion of the analyte(s) of interest (for improved detection selectivity and/or sensitivity) and sample pretreatment (for trace enrichment and clean-up). The above is especially true when, as is often the case today, relatively polar drugs, endogenous compounds, additives or environmental pollutants and/or their (bio)-degradation products have to be determined. For such classes of compounds high-performance column liquid chromatography (HPLC) generally is the preferred method of separation. Reversed-phase HPLC with fluorescence detection is a powerful means of analysis for compounds which possess native fluorescence. They are, however, relatively few in number. In order to make the method useful for a much wider range of analytes, one can therefore resort to derivatization (labelling) or other means of analyte conversion to obtain highly fluorescent reaction products, which can then be detected with the required selectivity and sensitivity. 4-Bromomethyl-7-methoxycoumarin is often used as fluorescent label for the determination of compounds possessing a carboxylic group. About 8% of the biologically interesting analytes--ranging from polar Amino acids and Peptides to apolar fatty acids--possess such a group.(ABSTRACT TRUNCATED AT 250 WORDS)