Fluorimetric derivatization

Derivatization of amino acids with [14C]DNS-C1 is very useful for protein sequencing [203,204]. The reactions involved are the same as described in the Fluorimetric Derivatization section (Section 4.2.1.1.1). The plates are observed under UV light for qualitative identification, but are quantitated by removing the spot from the plate for scintillation counting. Alternatively, the plates may be scanned with a radiochromatogram scanner. 

Fluorimetric derivatization Much more important is fluorimetric derivatization. The reason for this is that in biomedical analysis many of the native compounds, drugs, and drug metabolites are present at very low concentration (pg to ng ml ) excluding the possibility of using the insensitive UV detector both for underivatized and derivatized analytes. The high sensitivity of fluorimetric detection enables the limit of detection to be decreased by several orders of magnitude. It should be noted, however, that for complex matrices as, for instance, dealt with in environmental samples the chemistry as such becomes the crucial step the derivatization has to be successful for very low analyte concentrations in the presence of many possible matrix interferences. Nonetheless, HPLC with a fluorimetric detector is a very useful tool in biomedical analysis. Since only a limited number of analytes possess sufficiently strong native... 

Figure 6 Anion fluorimetric derivatization through redox reactions.

Pre-column fluorimetric derivatization of adenosine and its cyclic monophosphate with chloroacetaldehyde, and pre-column chemiluminescence derivatization of 5-fluoropyrimidines with 7-diethylamino-3-(4-iodoacetamidophenyl)-4-methylcoumarin, have yielded derivatives suitable for reversed-phase h.p.I.c. analysis. 

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