Time-resolved fluorescence spectroscopy global analysis

This interpretation was confirmed by time-resolved fluorescence spectroscopy using the single photon timing technique. The pentad as a 1 X 10 M solution in chloroform was excited at 590 nm, and emission decay curves were recorded at 14 wavelengths. All 14 decays were then fit simultaneously to four exponential functions (x = 1.12) using a global analysis technique. The results were used to construct the decay associated spectrum shown in Figure 16. The two major components of the decay had lifetimes of 0.039 and 1.2 ns. (The two minor components represent impur-... 

The value of trilinear models is clearest in steady-state fluorescence measurements. They are also valuable in time-resolved fluorescence spectroscopy in situations where the appropriateness of a specific parametric equation for time decay, such as a sum of a few exponentials, is unclear. Although we are unaware of any work using trilinear models with other kinds of excited-state spectroscopy, trilinear models will be a valuable means of achieving component resolution whenever the absence of reliable parametric equations makes global analysis impossible. 

A general discussion of the use of least-squares fitting in fluorescence measurements may be found in (28). The global analysis of fluorescence data is discussed in (29). Commercially available time-resolved fluorimeters are typically sold with data analysis software included. Available stand-alone packages include the Globals Unlimited suite, which is capable of analysing both time- and frequency-domain data, stopped-flow kinetics, etc. The Center for Fluorescence Spectroscopy at the University of Maryland (USA) also offers software for frequency- and time-domain fluorescence lifetime analysis. 

---