RESPONSE RATIO CHROMATOGRAMS FROM A DUAL-CHANNEL DETECTOR

A computer algorithm and various readout modes have been developed that allow the average slope ratios from a dual-channel flame photometric detector (FPD) to be calculated for peak sections in manual mode and for whole or split peaks in automatic modes. The latter are available in numeric and (chromato)graphic form on printer, screen, and recorder. Such response ratio chromatograms routinely add a chemical dimension to the physical dimensions of quantity and retention, as depicted by conventional chromatograms. In the case of the FPD, they indicate the presence and nature of FPD-active elements. Response ratios can also assess peak homogeneity, confirm peak identity, and facilitate ''subtraction'' and ''element-specific'' chromatographies. The use of automatically procured response ratios for these routines is demonstrated on computer-stored separations of compounds containing various transition and main-group elements.