Chemical derivatization processes applied to amine determination in samples of different matrix composition

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Pharmaceutical and forensic drug applications of chiral supercritical fluid chromatography

The supercritical fluid is an excellent choice as the chromatographic mobile phase because it allows rapid separation with high efficiency and applications involving enantioresolution are common. Supercritical fluid chromatography (SFC) is increasingly used for analytical, semi-preparative and preparative purification of chiral compounds, including production of enantiomers that are mainly encountered during drug development. SFC can be used as an alternative to HPLC for many drug substances, so it is gaining popularity in the pharmaceutical industry. The main advantages of SFC in separating chiral pharmaceuticals are: high speed, short analysis time, limited environmental impact and high efficiency. The reduction in the use of organic solvents has cost, health, and safety benefits. Due to these advantages, SFC fulfills all the requirements of Green Analytical Chemistry approaches. In this article, we present application of SFC as a tool for chiral separation of pharmaceuticals and drugs of abuse

Occurrence and determination of pesticides in natural and treated waters

Pesticides as environmental pollutants are described in detail along with their sources and paths of entry into various elements of the environment. Comprehensive literature data on the concentration of these pollutants in natural and treated waters and wastewaters are discussed. A wide selection of isolation and preconcentration techniques for these pollutants in water is presented and discussed. An emphasis is put on solid-phase extraction. In the case of the authors\u27 work, a more detailed description is given

Determination of organochlorine compounds in water from the Vistula River and seawater from the Gulf of Gdansk. River Quality: Dynamics and Restoration 1997, pp. 221-226.

Organohalogen compounds are among the most dangerous environmental pollutants, due to their toxic, mutagenic, and carcinogenic properties. Volatile organohalogen compounds enter rivers and seas through the municipal and industrial sewage. Pesticides are washed out from soil by rain and groundwater and flow into rivers and seas. If the high concentrations of lindane and methoxychlor in the Vistula River are believable, the relatively high concentrations of the analytes in the sea water in Gdynia Orlowo are striking. The studied surface waters, rivers, and lakes were found to be very polluted by anthropogenic compounds originating from municipal and industrial sewage and from agriculture. This results in the potential pollution of sea water and even underground and tap waters. These compounds are all very dangerous for human health and for the environment. The chapter also lists the results of the volatile organohalogen compounds in the water samples taken from Vistula River, Borowo Lake, and Straszyn Reservoir (water intake of Gdansk).Organohalogen compounds are among the most dangerous environmental pollutants, due to their toxic, mutagenic, and carcinogenic properties. Volatile organohalogen compounds enter rivers and seas through the municipal and industrial sewage. Pesticides are washed out from soil by rain and groundwater and flow into rivers and seas. If the high concentrations of lindane and methoxychlor in the Vistula River are believable, the relatively high concentrations of the analytes in the sea water in Gdynia Orlowo are striking. The studied surface waters, rivers, and lakes were found to be very polluted by anthropogenic compounds originating from municipal and industrial sewage and from agriculture. This results in the potential pollution of sea water and even underground and tap waters. These compounds are all very dangerous for human health and for the environment. The chapter also lists the results of the volatile organohalogen compounds in the water samples taken from Vistula River, Borowo Lake, and Straszyn Reservoir (water intake of Gdansk).B

Toenail selenium level among healthy residents of two Polish Districts

Radiation, Radionuclides and ReactorsApplied Science

Ocena wpływu czynników konstytucjonalnych na dzienne spożycie selenu na przykładzie mieszkańców województwa pomorskiego

In the current work, dietary intake of selenium was studied among adults residents of Pomeranian District. Concentration of selenium in diet samples was determined using Hydride Generation Atomic Absorption Spectrometry (HGAAS) technique after microwave digestion. The analyses of the 1 - day food ratios showed that the participants consumed insufficient levels of selenium with reference to Recommended Dietary Allowance what may constitute a risk for the deficiency of this element in human body. Moreover, the statistical analysis demonstrated a significant effect of the gender, age, and body mass index upon the dietary intake of selenium.W pracy dokonano oceny realizacji zapotrzebowania na selen w całodziennych racjach pokarmowych pobranych metodą podwójnej porcji wśród mieszkańców województwa pomorskiego. Oznaczanie Se przeprowadzono techniką generowania wodorków w połączeniu z absorpcyjną spektrometrią atomową (HGAAS) po uprzedniej mineralizacji próbek żywności. Analiza całodziennych racji pokarmowych pozwoliła na stwierdzenie, że ilość selenu przyjmowanego wraz z dietą jest niewystarczająca i może stanowić duże ryzyko niedoboru tego pierwiastka w organizmie. Ponadto, przeprowadzona analiza statystyczna wykazała wpływ płci, wieku oraz wskaźnika masy ciała na zawartość selenu w badanych próbkach żywnościowych

Chiral analysis of chloro intermediates of methylamphetamine by one-dimensional and multidimentional NMR and GC/MS

Impurity profiling and classification of abused drugs using chiral analytical techniques is of particular interest and importance because of the additional information obtained from this approach. When these methods are applied to the synthesis of illicitly used substances, they can supply valuable information about the conditions/chemicals used in the synthesis. We have applied GC and NMR methods to the study of intermediates found in methylamphetamine manufacture with the aim of linking the intermediates to the ephedrine/pseudoephedrine starting materials. Therefore, determination of the stereochemical makeup within samples of forensic interest is important giving further specific information to the analyst. This study investigates the stereochemical course of the Emde synthesis of methylamphetamine with particular focus on intermediate formation via the chlorination of ephedrine and pseudoephedrine enantiomers. The configurations of these chloro-phenethylamines were determined by 1D and 2D NMR analysis, and thereafter, the GC/MS analysis was carried out. We have shown here that chlorination of the ephedrine/pseudoephedrine compounds occurs via inversion (SN2) and retention (SNi) of configuration around the α carbon and mixture of diastereoisomers (chloroephedrine and chloropseudoephedrine) were formed, with the ratio of the resulting compounds dependent on the precursors used. The preparation and analytical properties of these intermediate standards provide data for laboratories interested in the stereochemical analysis of methylamphetamine intermediates such as forensic/law enforcement, and illustrate the value of using a combination of analytical methodology

Capillary gas chromatography using a γ-cyclodextrin for enantiomeric separation of methylamphetamine, its precursors and chloro intermediates after optimization of the derivatization reaction

The enantiomeric ratio of methylamphetamine (MAMP) is closely related to the optical activity of precursors and reagents used for the synthesis and this knowledge can provide useful information concerning the origins and synthetic methods used for illicit manufacture. The information can be utilized for regulation of the precursors and investigation of the manufacturing sources but this requires analytical procedures to determine purity of drug substances, impurity profiling and enantiomeric composition. In this study, a gas chromatography (GC) coupled with mass spectrometry (MS) method using a γ-cyclodextrin chiral stationary phase was developed and optimized for the simultaneous enantiomeric separations of MAMP and its common precursors, ephedrine, and pseudoephedrine, as well as its chlorointermediates formed during MAMP synthesis by the Emde method, after derivatization with trifluoroacetic anhydride. The optimization was performed using multivariate statistics (cluster analysis and principal components analysis) in order to select and compare optimal experimental conditions. Under the optimized experimental conditions, the calculated calibration curves showed good linearity range up to 0.1 μg/mL for all tested analytes. The limits of detection were in the range of 0.002–0.008 μg/mL and the coefficient of variability was between 1.0 and 3.9%. The method has the advantage of achieving excellent precision under repeatability and reproducibility conditions while detection by MS allows for the identity of analytes to be confirmed in a single analysis. The method was therefore applied satisfactory to MAMP analysis