The determination of stoichiometries and stability constants of complexes by means of UV-visible spectrophotometry applying traditional methods does not evaluate the quality of the values obtained, since the classic application of these methods does not provide coverage intervals. However, the use of chemometric techniques in different steps of the application of these methods makes it possible...

The UV-spectrophotometric method of analysis was proposed for simultaneous determination of fluoxetine (FLX) and sertraline (SRT). Considering the strong spectral overlap between UV-Vis spectra of these compounds, a previous separation should be carried out in order to determine them by conventional spectrophotometric techniques. Here, full-spectrum multivariate calibrations adaptive neuro-fuzz...

Two series of free-base and manganese N-methyl-pyridylethynyl-5,15-biphenyl porphyrins were synthesized, and their UV-Visible, electrochemical and spectro-electrochemical properties were studied. Cyclic voltammetry experiments showed positive shifts in the reduction potentials and the UV-Visible spectra showed significant red-shifts in the absorption wavelengths of these porphyrins, indicating ...

Studies on hot carrier science and technology associated with various types of nanostructures are dominating today's nanotechnology research. Here we report a novel synthesis of polyaniline-gold (PAni-Au) nanocomposite thin films with gold nanostructures (AuNs) of desired shape and size uniformly incorporated in the polymer matrix. According to shape as well as size variation of AuNs, two tunab...

Porous silicon samples were prepared by electrochemical etching method for different etching times. The structural properties of porous silicon (PS) samples were determined from the Atomic Force Microscopy (AFM) measurements. The surface mean root square roughness (σ rms) changes as function of porosity were studied, and the influence of etching time on porosity and roughness was studied too. U...

Maillard reaction (MR) was carried out in L-lysine-D-glucose (Lys-Glu) model system heated at 120°C for 0 to 10 h without pH control. Optical property (UV-Vis absorbance and fluorescence) development of MR was monitored. Antioxidant activity of maillard reaction products (MRPs) was investigated by a series of in vitro tests. The UV-Vis absorbance zero and first-order derivative spectrophotometr...

Porous silicon samples were prepared by electrochemical etching method for different etching times. The structural properties of porous silicon (PS) samples were determined from the Atomic Force Microscopy (AFM) measurements. The surface mean root square roughness (σ rms) changes as function of porosity were studied, and the influence of etching time on porosity and roughness was studied too. U...

NASA’s Stardust mission flew through the coma of comet Wild 2 in January 2004, capturing dust grains as it did so. The grains were returned safely to Earth in January 2006, and are in the process of being distributed to investigators. As members of the Spectroscopy Preliminary Examination Team, we are preparing to analyse Stardust grains. Our contribution is to measure the spectrum of the grain...