second order advantage of excitation-emission fluorescence matrix was applied for the simultaneous determination of ibuprofen and caffeine. the proposed method is based on the measurement of the native fluorescence and recording emission spectra of ibuprofen and caffeine in different excitation wavelengths. the mixture of these compounds was resolved by multivariate curve resolution coupled wit...

A simple and sensitive method for the determination of carbaryl in whole blood and commercial formulations, based on normal, and synchronous firstand second-derivative fluorescence spectra, is presented. Solvent effects on the spectral characteristics of carbaryl solutions and the influences of instrumental parameters are described in detail. Two methods have been developed, with neutral (for c...

Mixtures of the three major metabolites of acetylsalicylic acid (salicylic, gentisic and salicyluric acid) were analyzed by synchronous molecular fluorescence spectroscopy. Three-way data matrices were generated by acquisition of spectra as a function of the pH (between 2 and 11) and of different relative concentrations of the three components. The PARAFAC trilinear model, without restrictions ...

The maximum yield of oxygen production in Chlorella was found, in new, systematic experiments, not to exceed o.12, under a great variety of conditions. Measurements were made on autospores and other synchronous cultures, at different CO~ concentrations, at very low light intensities, and in the presence of 'catalytic ' amounts of blue light. The action spectra (quantum yield as a function of wa...

In this study, a fluorescence approach was used to evaluate the production of soluble microbial products (SMP) in aerobic granular sludge system under the stress of 2,4-dichlorophenol (2,4-DCP). A combined use of three-dimension excitation emission matrix fluorescence spectroscopy (3D-EEM), Parallel factor analysis (PARAFAC), synchronous fluorescence and two-dimensional correlation spectroscopy...

A biologically active antibacterial reagent, 2-amino-6-hydroxy-4-(4-N, N-dimethylaminophenyl)-pyrimidine-5-carbonitrile (AHDMAPPC), was synthesized. It was employed to investigate the binding interaction with the bovine serum albumin (BSA) in detail using different spectroscopic methods. It exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus which are common food...

Spectral changes of bovine serum albumin (BSA) in the presence of dipicolinic acid (DPA) were studied with UV/Vis absorption and fluorescence spectroscopy. The change in UV/vis spectra of BSA in the presence of DPA indicated the protein weakly interacting with DPA. The DPA quenching to the fluorescence of BSA leads to the calculation of the BAS-DPA association constant K of 8.9 x 104 Lmol-1 at ...

Fluorescence spectra of proteins are determined chiefly by the polarity of the environment of the tryptophan and tyrosine residues and by their specific interactions. A thorough consideration of fluorescence spectrometers and their calibration is provided along with important information regarding spectrometer cells, buffers and clarification of samples. Protocols are provided for recording flu...

Capillary electrophoresis separation and synchronous fluorescence spectral detection was used off-line to reveal the nature of fluorescent adducts formed in vivo in the collagen molecule and their distribution in the molecule. It was shown that by using the delta lamda in the area of the Stokes shift for the analyzed entities (approximately 10 nm for pentosidine, 4,5(E)-epoxy-2(E)-heptenal and ...