Identification Of Compounds In Water Research Articles

INVESTIGATION OF PHENOLIC COMPOUNDS IN EXTRACTS FROM THE LEAVES OF LAURUS NOBILIS L.

Laurus nobilis L. is an evergreen dioecious, rarely monecious plant up to 15 m high. Its natural area includes Mediterranean countries. For a long time this plant has been actively cultivated as a decorative plant in (Europe, Russia, USA and others) as well as in Turkey, Algeria, Morocco, Spain, France, Italy, Portugal, Mexico and Russia. Chemical composition of the Laurus leaves include essential oil components, sesquiterpenic lactones and phenolic compounds as the principal active groups of compounds. The aim of the study was the identification of phenolic compounds in water and water alcohol extracts from leaves of Laurus nobilis. Materials and methods. Examinations of qualitative composition of phenolic complex in extracts from Laurus samples under study were carried out using «Hitachi Chromaster» high-performance liquid chromatographer with «Column Oven 5310», «Pump 5110» and «UV-detector 5410». Results and discussion . The samples of Laurus nobilis leaves gathered in outskirts of Alushta (Republic of Crimea) in July 2016 were the objects if the study. We identified caffeic, gallic, and chicoric acids, epigallocatechin gallate, luteolin-7-glycoside in the extracts obtained using ethanol 70%. And caffeic, gallic, isoferulic acids, dicoumarin, epicatechin, kaempferol, and isoquercitrin in ethanol 40% extracts. In water extracts we found the presence of ascorbic, gallic, and vanillic acids, epicatechin, quercetin-3-glycoside and kaempferol-3-galactoside. Conclusion . As the result of the Laurus nobilis leaves samples study, gathered in Alushta outskirts, ascorbic acid and 13 phenolic compounds were identified in water and water-alcohol (40% and 70%) extracts using high performance liquid chromatography. Isoferulic and chicoric acids, epigallocatechin gallate, dicoumarin, kaempferol, isoquercitrin, kaempferol-3-galactoside and luteolin-7-glycoside were identified in Laurus nobilis leaves for the first time.

Iodinated X-ray contrast agents: Photoinduced transformation and monitoring in surface water

Conventional wastewater treatment methods have shown to be unsuitable for a complete elimination of iodinated X-ray contrast agents (ICMs), which have thus been found in wastewater treatment plant (WWTP) effluent and in surface water. Once in the surface water, they could be transformed through different processes and form several transformation products that may need to be monitored as well. To this end, we studied the abatement and transformation of ICMs by combining laboratory experiments with in field analyses. We irradiated different aqueous solutions of the selected pollutants in the presence of TiO2 as photocatalyst, aimed to promote ICMs degradation and to generate photoinduced transformation products (TPs) similar to those occurring in the environment and effluent wastewater. This experimental strategy has been applied to the study of three ICMs, namely iopromide, iopamidol and diatrizoate. A total of twenty-four, ten, and ten TPs were detected from iopamidol, diatrizoate and iopromide, respectively. The analyses were performed using a liquid chromatography-LTQ-FT-Orbitrap mass spectrometer. The mineralization process and acute toxicity evolution were assessed as well over time and revealed a lack of mineralization for all ICMs and the formation of harmful byproducts.After characterizing these transformation products, WWTP effluent and surface water taken from several branches of the Chicago River were analyzed for ICMs and their TPs. HRMS with MS/MS fragmentation was used as a confirmatory step for proper identification of compounds in water and wastewater samples. All three of ICM were detected in the effluent and surface water samples, while no significant amount of TPs were detected.

Identification of Compounds in Water Above a Pollutant Plume by High-Resolution Mass Spectrometry

Identification of compounds in contaminated media is essential for determining sources of pollution and for assessing risks posed by the chemicals to ecosystems or human health. Eighty-five compounds were identified or tentatively identified in a 1-L extract of water sampled above a pollutant plume containing wastes from a chemical plant. Gas chromatography/high-resolution mass spectrometry determined exact masses of apparent molecular ions and the exact masses and RIAs (relative isotopic abundances) of their +1 and +2 isotopic mass peaks, which provided their elemental compositions. Ion compositions, mass spectral libraries, the presence of related compounds, and knowledge of organic chemistry provided tentative identifications, half of which were confirmed by comparison of analyte retention times and mass spectra with those of standards.