This paper describes the technique of excitation energy site-selection (SS) phosphorimetry for chemical analysis of polycyclic aromatic compounds in Shpolskii matrices at 4.2 K. The principle of the SS phosphorescence technique, which uses excitation via the singlet state and produces narrow-band phosphorescence, is discussed. The analysis of a three-component mixture is used to illustrate the spectral selectivity of the SS phosphorimetric technique.
Tuan Vo-Dinh and Michael Lamotte, "Site-Selection Phosphorimetry Via Singlet-State Excitation," Appl. Spectrosc. 42, 65-68 (1988)