ISSN:
1573-4994
Schlagwort(e):
Fluorescence titration
;
fluorescent ion indicator
;
decay time analysis
;
Mag-fura-2
;
SBFO
;
APTRA-BTC
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Physik
Notizen:
Abstract A test based on time-resolved fluorescence experiments (Anal. Biochem. 245, 28–37, 1997) allows one to assess the interference of the excited-state association with the fluorimetric determination of the ground-state dissociation constant K d of fluorescent ion:indicator complexes. If an inflection point occurs in the plot of the fluorescence signal vs – log[ion] in the ion concentration range where both decay times are invariant, this inflection point can be associated with the correct K d. Here we apply this test to the fluorescent ion indicators SBFO (for Na+), Mag-fura-2 (for Mg2+), and APTRA-BTC (for Ca2+). In all three cases the decay times are invariant in the concentration ranges of the respective ions where the fluorescence titrations show unique inflection points, indicating that the fluorimetrically determined K d values are the true K d values.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1023/A:1020572715655
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