An Instrument for Determining Single and Multiple Room-Temperature Phosphorescence Lifetimes

Abstract

A Room-Temperature Phosphorescence Lifetime Spectrometer (RTPLS) capable of resolving multicomponent intensity decays into separate lifetimes is described. Careful blank subtraction facilitated by a reproducible chopped-xenon arc source and data reduction with the use of nonlinear least-squares reconvolution are major features of the RTPLS. The performance and limitations of the RTPLS were evaluated with synthetic data and prepared samples. Better than 2% RSD was attained for multiple determinations of a single sample. 4-amino-1-naphthalenesulfonate, sodium salt and 2-naphthalenesulfonate, sodium salt both exhibit decays resolvable into two lifetimes when they are coadsorbed with NaI onto filter paper. The approximate ratio of the lifetimes is 1 to 10, and the shorter component is proposed to be a charge transfer complex between the analyte and NaI.