Study of aquatic chlorination of UV-filter avobenzone in the presence of inorganic salts by gas chromatography combined with high resolution mass spectrometry


E.A. Detenchuk, J. Chen, O.V. Polyakova, P. Trebse, S.A. Pokryshkin, A.T. Lebedev

Одной из важнейших стадий водоподготовки является ее обеззараживание. Это касается не только питьевой воды, но и, например, воды бассейнов. Самым распространенным методом для устранения микроорганизмов на сегодняшний день является хлорирование. Однако взаимодействие активного хлора с природными и антропогенными соединениями, растворенными в воде, приводит к образованию значительного числа химических соединений, многие из которых могут нанести вред человеку. Среди антропогенных соединений, ассортимент которых все возрастает год от года, определенную нишу занимают УФ-фильтры. Такие вещества относят к новым экотоксикантам, а их применение для защиты кожи набирает популярность во всем мире. В данной работе методом газовой хроматографии в сочетании с масс-спектрометрией высокого разрешения идентифицировано более 30 соединений, включая значительное число галогенпроизводных, образующихся в результате водного хлорирования популярного УФ-фильтра авобензона в воде в присутствии неорганических солей меди, железа, а также бромидов и иодидов. Исследования показали значительные вариации в качественном и количественном составе продуктов реакции в зависимости от добавки. Важно отметить образование бром- и иодсодержащих продуктов.

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Improved procedure for tandem gas chromatography/mass spectrometry detection of the globin adduct of sulfur mustard


N.L. Koryagina, M.D. Shachneva, A.I. Ukolov, E.I. Savel’eva, N.S. Khlebnikova, A.S. Radilov

Features of electron and chemical ionization mass spectra of derivatives of N-[2-[(hydroxyethyl)thio]ethyl]-DL-valine (НЕТЕ-Val)—a biomarker of sulfur mustard (SM) — recorded by GC-MS and GC-MS/MS were studied. The retention indices of the studied derivatives were measured. The optimized procedure of the GC-MS/MS (MRM mode) identification of НЕТЕ-Val was tested in the analysis of donor blood samples exposed in vitro to sulfur mustard. The linear range of the detector was 10 to 100 ng mL– and the detection limit was 10 ng mL–1 for SM.

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Converting gas chromatography/mass spectrometry data from NetCDF to CSV format


A.S. Samokhin

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Study of chlorination of UV-filter avobenzone in sea water by gas chromatography combined with high resolution mass spectrometry


A.А. Chugunova, M. B. Kralj, O.V. Polyakova, V.B. Artaev, P. Trebše2, S.A. Pokryshkin,
A.T. Lebedev

Disinfection represents an important step to purify drinking water as well as swimming pool water. The most widespread procedure involves chlorination which efficiently eliminates micro organisms. However reaction of active chlorine with dissolved organic matter results in formation of numerous organochlorine compounds representing certain hazard for environment and human health. UV-filters belong to emerging contaminants as their application for the skin protection from UV-irradiation becomes more and more popular all over the world. Certain components of UV-filters appear in swimming pools forming new ecotoxicants. In the present study 40 compounds including numerous brominated derivatives forming due to avobenzone chlorination in the sea water are identified by means of gas chromatography/high resolution mass spectrometry. In addition, the applicability of photocatalysis to destroy the forming products was checked. The procedure appeared to be rather efficient. It allows one to decrease the total quantity of avobenzone transformation products by a factor of 10. The only class of compounds demonstrating its stability in the applied conditions is halogenated derivatives of acetophenone.

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Determination of the geographical region of growing the coffee beans by gas chromatograph-combustion – isotope ratio mass spectrometry


A.M. Antokhin, V.F. Taranchenko, S.V. Vasilevsky, A.V. Aksenov, Ju.B. Aksenova, O.V. Kuznetsova,
I.V. Lapko, M.A. Glushkova

Gas chromatography –combustion –isotope ratio mass spectrometry has been used to study the changes in carbon isotopic composition of chlorogenic acid and caffeine extracted from samples of coffee beans of different origin. It has been shown that depending on the region of coffee beans growing, the relative characteristics of carbon isotopic composition, namely δ13C, ‰, changed significantly for both caffeine and chlorogenic acid. There was a decrease in the 13C isotope observed in the following order: Africa –South America –Central America. It has been found that the δ13C values for caffeine and chlorogenic acid, when mutually considered, provide the statistically significant identification of a region where the coffee beans grow.

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Mass spectrometry of analytical derivatives. 2. “Ortho” and “Para” effects in electron ionization mass spectra of derivatives of hydroxy, mercapto and amino benzoic acids


Нино Гурамовна Тодуа, Анзор Иванович Микая

Derivatives requiring either anhydrous or aqueous reaction conditions were prepared for robust and reliable gas chromatography/mass spectrometry (GC/MS) characterization of hydroxyl, mercapto, and amino benzoic acids. Methylation and trialkylsilylation are employed for blocking the acidic function. Alkyl, trimethylsilyl, acetyl, perfluoroacyl and alkoxycarbonyl derivatization groups are introduced to hydroxyl, mercapto and amino functions. The electron ionization induced fragmentation characteristics of corresponding derivatives are explained by comparing the MS1 spectra of unlabeled compounds to their 2H and 13C labeled analogs, and analysis of collision-induced dissociation data from MS2 spectra. Competing fragmentation alternatives are identified and specific decomposition processes are detailed that characterize (a) ortho isomers due to interaction of vicinal functional substituents and (b) para isomers prone to forming para quinoid type structures. Skeletal and hydrogen rearrangements typical for methyl benzoates and the blocking groups are considered when discussing diagnostically important ions. Characteristic ions produced as a result of rearrangements in ortho isomers are classified, and skeletal rearrangements required to produce para quinoid type ions specific for para isomers are noted. Key ions for structure elucidation and differentiation of isomers for derivatives of substituted benzoic acids by GC/MS are suggested.

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