Quantification of Airborne Concentrations of Nano And Micro Scale Phosphor Particles In The Manufacturing environment by Spectrofluorometric Method

In this work, nanoscale luminescent materials dispersed in the air were collected and quantified by the fluorescence spectroscopy. A well-known phosphor; LuAG:Ce3+ was chosen as the model particle due to its strong, measurable and repeatable signal which can easily be excited by the blue light and emits at yellow wavelengths. The ionic liquid modified polymethylmethacrylate based filters were fabricated by electrospinning technique. Samples were collected by means of a vacuum pump from the laboratory environment during the grinding, weighing, transfer, washing, drying and packaging of the phosphorus particles, for different time intervals. The spectrofluorometric method was used for the quantification of the airborne concentration of the nano and microscale dusts. Presented method was also tested in terms of precision, LOD, LOQ, and stability. To the best of our knowledge, this is the first attempt to measure the airborne concentrations of the nano-scale luminescent phosphor particles and can easily be adopted for the quantification of other nanoscale- emitting particles in workplaces. Additionally, the offered design allows miniaturization since it is possible to excite the particles with cost-effective LED based light sources, integrate the system with fiber optics and detect the received optical response by photodiodes.

Age-Related Changes in Zinc, Copper and Selenium Levels in the Human Prostate

Pathophysiological changes in the prostate gland—benign prostatic hyperplasia (BPH) and prostatic adenocarcinoma (PCa)—are closely related to the age of men. In the prostate gland, zinc is of particular importance for its proper functioning, especially with regard to the effects of hormonal disorders. The aim of this study was to evaluate zinc, copper and selenium concentrations in different parts of the prostate gland in relation to age and the nature of pathological changes. Zinc and copper were determined by the AAS method and selenium by the spectrofluorometric method. The concentration of zinc in the central part of the prostate increases with age, and in patients over 36 years it is twice as high as in the peripheral part, where no increase in the level of this element was observed with the age of patients. The above data confirm a possible influence of zinc on the formation of PCa (located mostly in the peripheral part of the prostate, with low levels of zinc) and BPH in the central part where the levels of this element are the highest. The results apparently confirm the disturbed homeostasis of zinc and other essential elements in the etiology of BPH and PCa.

Studying the quenching resulted from the formation of an association complex between olsalazine or sulfasalazine with acriflavine

We report the detection and quantification of important ulcerative colitis drugs olsalazine (OLS) and sulfasalazine (SUL) by the spectrofluorometric method. The proposed method was optimized and validated by using the quenching effect on the acriflavine fluorescence. The method was applied on the detection and quantification of OLS and SUL under optimized conditions showing the calibration curves were linear (range: 1.0–10.0 µg ml −1 ), with correlation coefficients R 2 of 0.9999 for both drugs. The limits of detection (LOD) and quantification (LOQ) were 53 and 104 ng ml −1 for the OLS and 160 and 315 ng ml −1 for the SUL. This method permitted the analysis of OLS and SUL in their pure and pharmaceutical forms. The proposed spectrofluorimetric method was also evaluated against ‘green’ criteria and all the experimental results make it an eco-friendly and safe method for the detection of OLS and SUL.

Investigation and Analytical Applications of the Reaction of N1-Methylnicotinamide and Active Methylene Containing Drugs

Background: The reaction between N1-methylnicotinamide iodide (NMNI) and the active methylene group containing compounds yields a fluorescent product, which can be used in the quantitative determination of certain drugs. Objective: The objective is to develop, adapt and validate a simple spectrofluorometric method for the quantitative analysis of modafinil 1, budesonide 2, allicin 3 and florfenicol 4. Results: A C4 cyclization pathway was confirmed for the formation of the fluorophore. The spectrofluorometric method showed good linearity (R2= 0.996-0.999) over concentrations of 1-50 ng/mL, 0.5-5 ng/mL, 60-150 pg/mL, and 1-15 ng/mL of the standard solutions of 1, 2, 3, and 4, respectively. Methods: Spectral analysis (elemental analysis, 1H, 13C NMR, MS), computational methods (geometry optimization, Gibbs free energy and pKa calculations) and spectrofluorometric approaches were conducted. Conclusion: The proposed method is simple and suitable for quality control and assurance studies