Fig. 14.
Resolution of the initially excired and relaxed states of N-acetyl-l-tryptophanamide by phase-sensitive detection of fluorescence. Excitation was through a 280 nm interference filter with 10 nm band pass. Emission was observed through a monochromator with a band pass of 8 nm. The concentration of NATA was 5 × 10−5 M. For the spectra shown polarizers were nor used. Measurements with polarizers set at the magic angle [22] gave equivalent results with a decreased signal-to-noise raatic.