Fluorometric titration

Fig. 11 (a) Chemical structure left, 9 90°) and cation response right) of virtually decoupled probe 30 for Hg2+ and Ag+. Absorption and emission spectra of 30 in the absence (black, dotted line = fit of the CT emission LE = fluorophore-localized emission band) and presence (at full complexation) of Hg2+ red) and Ag+ blue) in MeCN fluorometric titrations of 1 with Hg2+ and Ag+ shown in the inset FEF (LE) determined from the integrated fluorescence intensity of the LE band, (b) Chemical structures of other virtually decoupled probes for Na+ (31), Pb2+ (32), and Ni2+ (33). For color code, see Fig. 3. (Adapted in part from [115], Copyright 2000 American Chemical Society)...

The value of the excited-state pK can be determined by fluorometric titration, but only when the equilibrium is established in the excited state. 

Figure 11. Terbium fluorometric titration of azoalbumin containing an average of 1.6 EDTA groups per albumin molecule (O) azoalbumin, 0.14mM in 0.1 M sodium citrate, pH 6.5 (X) pepsin-digested azoalbumin, 0.17mM sodium citrate, pH 6.5. Adding terbium(III) to solutions having equal concentrations of native albumin or of pepsin-treated native albumin did not lead to detectable fluorescence under...

Figure 6.6.2 (a) Spectrophotometric titration curve of the tetracationic porphyrins 1-4) with the tetraanionic porphyrinate TPPS" (5) in water/methanol 1 1. Pure water can also be used as a solvent, but the absorption bands then are slightly broader, the isosbetic points less sharp, (b) The corresponding Job plot, (c) Fluorometric titration of the isomer 1-4) mixture with CuTPPS" in water.The assumed molecular structure of the dimer is also indicated. (From Endisch et al., 1996.)... 

Norris, A W, Cheng, L, Giguere, V, Rosemberg, M, and Li, E (1994) Measurement of subnanomolar retinoic acid binding affinities for cellular retinoic acid-bmdmg proteins by fluorometric titration Biochim Biophys Acta 1209, 10-18... 

CRABP from bovine retina has one binding site for retinoic acid (Saari et al., 1978a). The apparent dissociation constant for a pure preparation of rat testicular CRABP has been estimated by fluorometric titration to 4.1 x M (Ong and Chytil, 1978b). Human breast tissue CRABP was reported to have an apparent dissociation constant of 2.5 X 10 " M, when determined by polyacrylamide disc gel electrophoresis method (Rung et al., 1980). 

A simple determination of riboflavin from urine and plasma based on a fluorometric titration was described by Kodentsova et al. (36). This method is based on the fact that the formation of riboflavin-apoprotein complex is accompanied by a complete loss of fluorescence peculiar to free riboflavin. A plasma sample of 1 mL was acidified by the addition of trichloroacetic acid. After centrifugation and neutralization, the fluorescence intensity was measured in a 3-mL cuvette (ex. 465 nm em. 525 nm). The measurement was repeated after addition of riboflavin standard and riboflavin-binding apoprotein, respectively. An amount of 1.5 ng riboflavin/mL plasma can be detected using this method. 

Petrov, J. G. Moebius, D. Determination of the electrostatic potential of positively charged monolayers at the air/water interface by means of fluorometric titration of 4-heptadecyl-7-hydroxycoumarin. Langmuir 1990, 6,746-751. 

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