Fluorescent materials being proposed as fluorescence standards by the National Bureau of Standards have been evaluated regarding 1. stability, 2. intensity, 3. spectra, 4. interference from scatter, and 5. lifetimes. The lifetimes of these inorganic phosphors imbedded in sintered polytetrafluoroethylene were in the microsecond-millisecond range, so they would not be useful as lifetime standards for solution organic chemistry. However, the spectra, intensity, stability, and correctable scatter suggest that the materials could be used to calibrate and standardize fluorometers. Only mechanical defects (sample size, warping of the sheets) were significant. The method for determining the association constants of tryptophan and tyrosine-containing peptides with cupric and nickel ions was developed and published. Quenching was the parameter used to quantitate binding. Interference from collisional quenching was considered to be negligible for studies of cupric ion binding, but could be a factor with nickel ion.
