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A. V. Brusnichkin, A. V. Marikutsa, M. A. Proskurnin, E. V. Proskurnina, A. N. Osipov, Yu. A. Vladimirov
Thermal-lens determination of cytochrome
cand its NO complex
Abstract
Spectrophotometric and
thermal-lens measurements showed that cw laser irradiation (450–530 nm, up to
100 mW) does not affect the apsorption band of cytochrome c, and thermal
lensing is used for determining cytochrome c (III) (cmin
= 1 ×10–7 M at l= 488.0 nm; cmin = 3 ×10–8 M at l = 514.5 nm)
and its active form, cytochrome c (II) (cmin
= 1×10–8 M at l = 514.5 nm). The enhancement in the sensitivity of determination
of these species compared to conventional spectrophotometry is more than two
orders. The optimum conditions for the formation of NO complex of cytochrome c
for its photometric determination are selected: the molar ratio of
dodecylsulfate (a modifying agent) to cytochrome c is 1: 30, the working
wavelength of 560 nm. The study of the effect of laser radiation on
nitroso-complex of cytochrome c showed that it dissociates forming
cytochrome c (III), and the monitoring of the decomposition of this
complex with thermal-lensing (514.5 nm) is possible at a level down to 1×10–7 M.
Copyright (C) Chemistry Dept., Moscow State University, 2002
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