O. V. Polyakova

Estimation of contamination of atmosphere of Moscow in winter

To establish the priority pollutants in the atmosphere of Moscow in winter 8 snow samples were collected along the perimeter (109 km) of the Moscow Ring Road. Mass spectrometry was used as an analytical tool to identify individual organic compounds (gas chromatography/mass spectrometry) and the most environmentally relevant chemical elements (inductively coupled plasma with mass spectrometric detection). As a result several hundred organic compounds belonging to various classes, including representatives of the list of priority pollutants of the USA Environmental Protection Agency were identified. Their levels as well as the levels of chemical elements were quantified. The importance of accurate mass measurements for the efficient structural elucidation and reliability of quantitative measurements has been demonstrated. The data obtained allow estimating atmospheric pollution in Moscow in the period between December and March and proposing a list of priority pollutants for the atmosphere of Moscow.

Photochemical fate and photocatalysis of 3,5,6-trichloro-2-pyridinol, degradation product of chlorpyrifos.

In this study we have focused on 3,5,6-trichloro-2-pyridinol (TCP), degradation product of chlorpyrifos. Photolysis experiments were conducted in order to elucidate its degradation mechanism. Identification of products was performed using the LC-MS technique. To evaluate the mineralization efficiency, TiO2 photocatalytic study was performed. Under photolytic experimental conditions, the concentration of TCP after 120 min of irradiation reached 5.9 ± 1.5% of the initial concentration, while chloride concentration reached approximately 73% of total chloride concentration. The TOC measurements after 120 min of photocatalytic degradation experiment revealed high mineralization rate, i.e. 53.6 ± 1.9%, while chloride concentration reached 26.6 mg L(-1) what means almost quantitative transformation of organic chlorine into chloride. TIC chromatogram (ESI, negative ion mode) of the reaction mixture after 30 min of irradiation revealed the presence of several peaks. One of them has already been reported previously. Two other products have been identified in this study for the first time. They have been formed by radical attack of the reactive OH(•) species on the carbonyl group followed by the corresponding N-C or C-C bond cleavages and recyclization with formation of the pyrrol structures substituted with carboxylic groups. Both deprotonated molecules easily lose CO2 in ESI conditions.

Determination of polycyclic aromatic hydrocarbons in water by gas chromatography/mass spectrometry with accelerated sample preparation

A novel simplified sample preparation method for quantitative analysis of polycyclic aromatic hydrocarbons (PAH) in water samples by gas chromatography/mass spectrometry (GC/MS) was proposed. The method requires just 1 mL of water and 1 mL of dichloromethane. The detection limits of PAH with the use of high resolution GC/MS are about 1 μg/Λ, while the limits of quantification—10 μg/L. These limits correspond to those for the standard 8270 method of the United States Environmental Protection Agency.

High field FT-ICR mass spectrometry for molecular characterization of snow board from Moscow regions

High field Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry analysis of eight snow samples from Moscow city allowed us to identify more than 2000 various elemental compositions corresponding to regional air pollutants. The hierarchical cluster analysis (HCA) of the data showed good concordance of three main groups of samples with the main wind directions. The North-West group (A1) is represented by several homologous CHOS series of aliphatic organic aerosols. They may form as a result of enhanced photochemical reactions including oxidation of hydrocarbons with sulfonations due to higher amount of SO2 emissions in the atmosphere in this region. Group A2, corresponding to the South-East part of Moscow, contains large amount of oxidized hydrocarbons of different sources that may form during oxidation in atmosphere. These hydrocarbons appear correlated to emissions from traffic, neighboring oil refinery, and power plants. Another family of compounds specific for this region involves CHNO substances formed during oxidation processes including NOx and NO3 radical since emissions of NOx are higher in this part of the city. Group A3 is rich in CHO type of compounds with high H/C and low O/C ratios, which is characteristic of oxidized hydrocarbon-like organic aerosol. CHNO types of compounds in A3 group are probably nitro derivatives of condensed hydrocarbons such as PAH. This non-targeted profiling revealed site specific distribution of pollutants and gives a chance to develop new strategies in air quality control and further studies of Moscow environment.

Novel pollutants in the Moscow atmosphere in winter period: Gas chromatography-high resolution time-of-flight mass spectrometry study ☆

The most common mass spectrometry approach analyzing contamination of the environment deals with targeted analysis, i.e. detection and quantification of the selected (priority) pollutants. However non-targeted analysis is becoming more often the method of choice for environmental chemists. It involves implementation of modern analytical instrumentation allowing for comprehensive detection and identification of the wide variety of compounds of the environmental interest present in the sample, such as pharmaceuticals and their metabolites, musks, nanomaterials, perfluorinated compounds, hormones, disinfection by-products, flame retardants, personal care products, and many others emerging contaminants. The paper presents the results of detection and identification of previously unreported organic compounds in snow samples collected in Moscow in March 2016. The snow analysis allows evaluation of long-term air pollution in the winter period. Gas chromatography coupled to a high resolution time-of-flight mass spectrometer has enabled us with capability to detect and identify such novel analytes as iodinated compounds, polychlorinated anisoles and even Ni-containing organic complex, which are unexpected in environmental samples. Some considerations concerning the possible sources of origin of these compounds in the environment are discussed.

Oxidative desulfurization of hydrocarbon fuel with high olefin content

The influence of olefins on the oxidative desulfurization of model mixtures and catalytically cracked gasoline has been studied. It has been established using model mixtures and a wide-cut fraction of catalytically cracked gasoline that the presence of olefins in fuel suppresses the oxidative desulfurization process as a result of occurrence of side oxidation reactions of unsaturated compounds. It has been shown that under the given conditions, it is preferable to use neutral catalysts based on transition metal salts for the oxidative desulfurization, rather than catalysts of acidic nature.

Snow Samples as Markers of Air Pollution in Mass Spectrometry Analysis

Snow can store with minimal further modifications the air born pollutants carried by winds over long distances. The “Cold Finger” phenomenon carries the pollutants from warmer zones toward cold ones i.e., to Polar Regions and high mountains. This automatic natural sample storage keeps them in fall out layers. Mass spectrometry provides information not only on the structures of the pollutants but also on their relations and sources. This issue helps in the analysis of even distant sources of pollution, as well as the problems of transboundary transfer. Both targeted and non-targeted analyses are applicable. Examples are given to illustrate the values of these technologies in the identification of distant pollution sources in Antarctica, Canada, Greenland, Finland, Russia, etc.

Detection of semi-volatile compounds in cloud waters by GC×GC-TOF-MS. Evidence of phenols and phthalates as priority pollutants

Although organic species are transported and efficiently transformed in clouds, more than 60% of this organic matter remains unspeciated. Using GCxGC-HRMS technique we were able to detect and identify over 100 semi-volatile compounds in 3 cloud samples collected at the PUY station (puy de Dôme mountain, France) while they were present at low concentrations in a very small sample volume (<25 mL of cloud water). The vast majority (∼90%) of the detected compounds was oxygenated, while the absence of halogenated organic compounds should be specially mentioned. This could reflect both the oxidation processes in the atmosphere (gas and water phase) but also the need of the compounds to be soluble enough to be transferred and dissolved in the cloud droplets. Furans, esters, ketones, amides and pyridines represent the major classes of compounds demonstrating a large variety of potential pollutants. Beside these compounds, priority pollutants from the US EPA list were identified and quantified. We found phenols (phenol, benzyl alcohol, p-cresole, 4-ethylphenol, 3,4-dimethylphenol, 4-nitrophenol) and dialkylphthalates (dimethylphthalate, diethylphthalate, di-n-butylphthalate, bis-(2-ethylhexyl)-phthalate, butylbenzylphthalate, di-n-octyl phthalate). In general, the concentrations of phthalates (from 0.09 to 52 μg L-1) were much higher than those of phenols (from 0.03 to 0.74 μg L-1). To our knowledge phthalates in clouds are described here for the first time. We investigated the variability of phenols and phthalates concentrations with cloud air mass origins (marine vs continental) and seasons (winter vs summer). Although both factors seem to have an influence, it is difficult to deduce general trends; further work should be conducted on large series of cloud samples collected in different geographic areas and at different seasons.

Semi volatile organic compounds in the snow of Russian Arctic islands: Archipelago Novaya Zemlya

Environmental contamination of the Arctic has widely been used as a worldwide pollution marker. Various classes of organic pollutants such as pesticides, personal care products, PAHs, flame retardants, biomass burning markers, and many others emerging contaminants have been regularly detected in Arctic samples. Although numerous papers have been published reporting data from the Canadian, Danish, and Norwegian Arctic regions, the environmental situation in Russian Arctic remains mostly underreported. Snow analysis is known to be used for monitoring air pollution in the regions with cold climate in both short-term and long-term studies. This paper presents the results of a nontargeted study on the semivolatile organic compounds detected and identified in snow samples collected at the Russian Artic Archipelago Novaya Zemlya in June 2016. Gas chromatography coupled to a high-resolution time-of-flight mass spectrometer enabled the simultaneous detection and quantification of a variety of pollutants including those from the US Environmental Protection Agency (EPA) priority pollutants list, emerging contaminants (plasticizers, flame retardants-only detection), as well as the identification of novel Arctic organic pollutants, (e.g., fatty acid amides and polyoxyalkanes). The possible sources of these novel pollutants are also discussed. GC-HRMS enabled the detection and identification of emerging contaminants and novel organic pollutants in the Arctic, e.g., fatty amides and polyoxyalkanes.

Polymer biquinolyl-containing complexes of Pd(II) as efficient catalysts for cyanation of aryl and vinyl halides with K4Fe(CN)6

A catalytic system for cyanation of aryl and vinyl halides with K4Fe(CN)6 based on a structurally tunable and nontoxic polymer backbone of polyamic type with biquinolyl fragments in the polymer chain capable of coordination to PdII ions is developed. The catalyst is eligible for thermal and microwave activation; in the latter case the reaction time is dramatically decreased. Cyanation of vinyl bromides occurs stereoselectively, and the configuration of the starting alkene is retained; even for Z-isomers the impact of configuration inversion is less than 5%. The polymer-based Pd catalyst is applicable for one-pot multi-step synthesis of the precursors of mesogenic structures of biphenyl type. Consecutive cross-coupling and cyanation reactions can be performed in the presence of the same portion of catalyst, in the same solvent, without isolation of intermediate products.