The water immersion of Pterocarpus wood produces strong blue fluorescence, which comes from the extract. fluorescence contained in extract is interest for identification wood. We conducted an investigation into extraction solution and analyzed mechanism this species. Possible species fluorescent molecules are discussed based on mixture. Liquid chromatography mass spectrometry (LC-MS) used analy...

A study of a simple and sensitive method for the determination of berberine, luguine and sanguinarine in mixtures by normal and synchronous derivative spectrofluorimetry is described. The influence of solvents and other experimental variables is discussed. A three-dimensional plot of both emission-excitation and synchronous spectra obtained by a new software program provides additional informat...

Robustness experiments are performed in analytical chemistry to assess the behaviour of an analytical procedure under conditions slightly different from those of the experimental optimum. This work presents a study of robustness applied to a previously proposed fluorescent methodology using two replicated 2(7-4) saturated fractional factorial designs. A comparison is established between three d...

Automated methods are described for extracting drugs from urine and for subsequently detecting them by ultraviolet or visible absorptiometry, or by spectrofluorometry. Standard Technicon AutoAn#{225}lyzer quipment has been adapted for use in the extraction processes; and manifolds for barbiturates, morphine, and bases are described. For drugs extracted from urine, the limits of detection were 2...

We report a rapid, simple, and sensitive spectrofluorometric procedure for total serum or plasma tryptophan. Plasma deproteinization, tryptophan extraction, and pH optimization are all carried out with a buffered cellulose/ethanol reagent. The fluorescence is measured at an emission wavelength of 350 nm, on excitation of 290 nm. Tryptophan fluorescence relative to concentration is linear up to ...

Concentrations of the environmentally sensitive elements (ESEs) As, Co, Cu, Mn, Ni, Pb, V and Zn in smaller than 100 μm street dust particles from Xining were measured using X-ray fluorescence spectrometry and their contamination levels were assessed based on enrichment factor (EF), geoaccumulation index (Igeo) and pollution load index (PLI). The concentrations of As, Co, Cu, Mn, Ni, Pb, V and ...