Chemiluminescence, time-delayed

The AED would represent a useful tool for the simultaneous selective detection of a number of elements occurring in pesticide molecules however, its rather high cost and maintenance requirements virtually ruled this detector out of the routine practice. The PEPD is another detector that can be tuned to selectively detect more elements (up to two simultaneously) based on their time-delayed chemiluminescence emission versus carbon. Thus, in contrast to the FPD that can only be employed either in phosphorus or sulfur mode, the PEPD offers simultaneous detection of these (or other) two elements. However, no element selective detector, even if it detects several elements simultaneously, is confirmatory without additional information because structural isomers with the same molecular formula may exist. 

The LS-3B is a fluorescence spectrometer with separate scanning monochromators for excitation and emission, and digital displays of both monochromator wavelengths and signal intensity. The LS-5B is a ratioing luminescence spectrometer with the capability of measuring fluorescence, phosphorescence and bio- and chemiluminescence. Delay time (t) and gate width (t) are variable via the keypad in lOps intervals. It corrects excitation and emission spectra. 

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