Post-column electrochemical oxidation

Boyer, G.L. and Goddard, G.D., High performance liquid chromatography coupled with post-column electrochemical oxidation for the detection of PSP toxins, Nat. Toxins, 7, 353, 1999. 

Fig. 6.1.9A-C Electrochemical detector (a) and florescence chromatograms (b), the latter generated following post-column oxidation. A Standards - 50 nM. 1 BH4 (retention time = 5.12 min) 2 dihydroneop-terin (retention time = 4.17 min), lox oxidized BH4 generated by electrochemical detector oxidation. N.B. This peak is variable in height/area and is not used for quantification ...

Detector E, Metrohm 1096/2, platinum working electrode +0.4 V, Ag/AgCl reference electrode following post-column reaction. The column effluent passed through an electrochemical cell (construction details in paper) and the bromide was oxidized to bromine at 3 pA. The mixture flowed through a 20 s reaction coil (3.9 m ( ) X 0.33 mm ID) to the detector. 

Post-column derivatlzation of reducing sugars with ethylene-diamine in a weakly alkaline medium at 150°C generates compounds detectable down to 1 pmol by electrochemical oxidation. This procedure was recommended over an earlier reaction involving 2-... 

HPLC Post-column derivatisation e.g. Ellman s reagent) Non-specific pre-column derivatisation e.g. of amino acids to form chromophores or fluorophores) Pre-column derivatisation to form fluorophores e.g. with bimanes, maleimides) Oxidative and reductive electrochemical detection... 

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