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Excitation Pulse Deconvolution in Luminescence Lifetime Analysis for Oxygen Measurements In Vivo ¶
Author(s) -
Mik Egbert G.,
Donkersloot Cornelis,
Raat Nicolaas J. H.,
Ince Can
Publication year - 2002
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/0031-8655(2002)0760012epdill2.0.co2
Subject(s) - phosphorescence , quenching (fluorescence) , excitation , luminescence , calibration , pulse (music) , chemistry , oxygen , materials science , persistent luminescence , analytical chemistry (journal) , optics , optoelectronics , fluorescence , detector , physics , thermoluminescence , chromatography , organic chemistry , quantum mechanics
ABSTRACT Oxygen‐dependent quenching of phosphorescence has been proven to be a valuable tool for the measurement of oxygen concentrations both in vitro and in vivo. For biological measurements the relatively long lifetimes of phosphorescence have promoted time‐domain–based devices using xenon arc flashlamps as the most common excitation light source. The resulting complex form of the excitation pulse leads to complications in the analysis of phosphorescence lifetimes and ultimately to errors in the recovered p O 2 values. Although the problem has been recognized, the consequences on in vivo phosphorescence lifetime measurements have been neglected so far. In this study, the consequences of finite excitation flash duration are analyzed using computer simulations, and a method for the recovery of phosphorescence decay times from complex photometric signals is presented. The analysis provides an explanation as to why different calibration constants are reported in the literature and presents a unified explanation whereby calibration constants are not solely a property of the dye but also of the measuring device. It is concluded that complex excitation pulse patterns without appropriate analysis methods lead to device‐specific calibration constants and nonlinearity and can be a potent source of errors when applied in vivo. The method of analysis presented in this article allows reliable phosphorescence lifetime measurements to be made for oxygen pressure measurements and can easily be applied to existing phosphorimeters.