Liquid chromatographic methods based on reversed-phase, ion-pair and ion-exchange chromatography coupled with ultraviolet spectrometry and tandem mass spectrometry have been developed and compared for the determination of 8-hydroxyquinoline in cosmetic samples. The individual parameters of different techniques are systematically optimized. The reversed-phase chromatography using ultrasonic extr...

The concentration of boron, an essential micronutrient for plants, presents a narrow range between deficiency and toxicity. In order to provide the boron requirement for plants, and to avoid toxicity problems, boron compounds are mixed with basic fertilizers. Sodium borate pentahydrate was used as a boron source. Ammonium orthophosphates fertilizers with boron were prepared by neutralizing phos...

Concentrations of As, Ca, Cd, Cl, Co, Cr, Cu, F, Fe, Hg, I, K, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Sn, V, and Zn were determined in human whole milk samples from Guatemala, Hungary, Nigeria, Philippines, Sweden, and Zaire; in most of these countries, three groups of subjects representing different socioeconomic conditions were studied. Analytical quality control was a primary consideration throu...

A commercially available direct mercury analyzer (DMA) based on sample combustion, pre-concentration by amalgamation with gold, and atomic absorption spectrophotometry (AAS) was coupled to a sector field inductively coupled plasma mass spectrometer (ICP-MS). The combined system (DMA-ICP-MS) was optimized and evaluated for the determination of mercury in environmental samples using both external...

The methods for quantitative determination of meloxicam and mefenamic acid in pharmaceuticals by classic spectrophotometry - zero order derivative, first and second order derivatives spectrophotometry is described, using "peak - peak" (P-P) and "peak - zero" (P-O) measurements. The calibration curves are linear within the concentration range of 4.0 - 14.0 microg/mL for meloxicam and 14.0 - 24.0...

Spectrophotometry has been the conventional technique for measuring optical density of irradiated gels [1]. Later, magnetic resonance imaging (MRI) was found to be capable of imaging radiation dose patterns in 3D [2]. Optical methods are still under investigation in the form of optical tomography [3– 6]. They promise to give three dimensional dose distributions without the cost attached to MRI....