Liquid chromatography with photolysis–electrochemical detection for nitro-based high explosives and water gel formulation sensitizers

Abstract The use of high performance liquid chromatography with photolysis–electrochemical detection (LC-hv-EC) for conventional high explosives has been improved through the use of a knitted open tubular (KOT) photolysis chamber geometry. Improvements in the analytical figures of merit and selectivity of this hybrid analytical technique are a direct result of the improved radial mass transfer of analyte in the KOT reactor, as demonstrated in comparisons with the coiled reactor geometry previously used. Using the KOT photolysis chamber geometry in LC-hv-EC, the limits of detection for aromatic C-nitro compounds, nitramines and nitrate esters are in the range of 120- to 250- pg injected. In addition, an off-line, pre-column chemical derivatization has been developed to convert water gel sensitizer residues to a form which will allow for their determination using LC-hv-EC. In a rapid, single-step process, 2,4-dinitrofluorobenzene (Sanger's reagent) is used to derivatize residues of monomethylamine and monoe...