MULTICHANNEL CHROMATOGRAPHY AND ONLINE SPECTRA FROM A FLAME PHOTOMETRIC DETECTOR

A rotating variable interference filter has been incorporated into a f lame photometric detector to acquire and simultaneously display low-re solution spectra that are diagnostic for eluting peaks. In its present form this approach yields ten chromatograms (for ten different wavele ngth segments) that are stored in the computer for subsequent data man ipulation such as baseline correction and curve smoothing; three-dimen sional display; peak and noise diagnostics; and magnification, subtrac tion, or elemental correlation of chromatograms. A third, spectral dim ension is thus added to the conventional two, chromatographic dimensio ns of retention time and analyte intensity. The three-dimensional perf ormance is at present accompanied by an order-of-magnitude loss in det ection limit and linear range. Typical one-segment (i.e. 5% dwell time ) elemental detectabilities, at S/N-p-p = 2, are 7 . 10(-13) g P/s (vi a HPO), 3 . 10(-11) g S/s (S-2*), 7 . 10(-12) g Ge/s (GeH*) and 4 . 1 0(-12) g Ru/s.