Resolution of multicomponent fluorescent mixtures by analysis of the excitation–emission–frequency array

Abstract

Fluorescence lifetime provides a third independent dimension of information for the resolution of total luminescence spectra of multicomponent mixtures. The incorporation of this parameter into the excitation–emission matrix (EEM) by the phase modulation technique results in a three‐dimensional excitation–emission–frequency array (EEFA). Multicomponent analysis based on the three‐dimensional EEFA brings a qualitative change for the resolved spectra, i.e. individual spectra can be uniquely resolved, which is impossible with any two‐dimensional analysis. In this paper we present a method for analyzing the EEFA. We show mathematically that with the three‐dimensional analysis of the EEFA individual spectra and lifetimes can be obtained. Our algorithm is developed in mathematical detail and is demonstrated by its application to a two‐component mixture.