New thermionic detector utilizing orthogonal nebulization for capillary column liquid chromatography.
A new version of the previously studied phosphorus-sensitive, dual-flame thermionic detector has been developed for microcolumn liquid chromatography. The total column effluent is orthogonally nebulized and aspirated directly into a primary air-hydrogen diffusion flame. Phosphorus compounds with molecular weights extending beyond 500 a.m.u. are then selectively detected by measuring the conductivity of the secondary flame in the presence of a rubidium silicate bead. The sensitivity was found to be 1.36 X 10(-11) g phosphorus/sec at the maximum of a Gaussian peak, and the signal increased linearly with concentration over 2 orders of magnitude for dilute samples. Possible mechanisms accounting for the negative orientation of the signal and for the limited dynamic range are discussed.
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002853:Chromatography, Liquid / Q000295:instrumentation*; D008970:Molecular Weight