A phosphorus-sensitive molecular emission cavity analysis detector for high-performance liquid chromatography

Molecular emission cavity analysis is adapted to monitor organophosphorus compounds emerging from both normal-phase and reversed-phase columns. Reproducibility of detection was ca. 3% (using peak area measurements) and sub-microgram quantities were easily detectable. The detector consists of a water-cooled duralumin disc with 40 cavities drilled into its circumference. Eluent is collected in the cavities and rotated stepwise into a H₂—N₂—air flame where the HPO emission is monitored at 528 nm. During rotation, the bulk mobile phase is completely evaporated. Examples are given of separations of phosphate esters, phosphonates, pyrophosphonates, phosphonic acids and pesticides. The detector also operates as a sulphur-selective detector at 384 nm.