Dmitry M. Mazur

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.

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.

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.

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.

Identification and interconversion of isomeric 4,5-functionalized 1,2,3-thiadiazoles and 1,2,3-triazoles in conditions of electrospray ionization

Graphical abstract Figure. No Caption available. HighlightsNew mass spectrometry approach for recognition of 4,5‐functionalized 1,2,3‐thiadiazoles and 1,2,3‐triazoles was developed.Several marker ions related to the structure of different isomers were proposed.Fragmentation schemes for 4 pairs of 4,5‐functionalized 1,2,3‐thiadiazoles and 1,2,3‐triazoles were proposed.Similar interconversion of isomeric 4,5‐functionalized 1,2,3‐thiadiazoles and 1,2,3‐triazoles was observed under ESI–MS/MS and in solution. Abstract 1,2,3‐Triazoles and 1,2,3‐thiadiazoles have been receiving permanent interest due to their exciting chemical reactivity and interesting biological properties including antibacterial, anticancer and antiviral activities. There are four compounds bearing 1H‐1,2,3‐triazole core in clinical studies which may appear in the market of drugs in nearest future. Definitely reliable methods of their identification and quantification should be developed by that time. Mass spectrometry showed itself as the most reliable method of analysis when dealing with trace levels of organic compounds in the mixtures and in the most complex matrices, including biological ones. In the present study tandem mass spectrometry was used to study fragmentation pathways of protonated and deprotonated molecules of isomeric 4,5‐functionalized 1,2,3‐thiadiazoles and 1,2,3‐triazoles in conditions of electrospray ionization (ESI). A group of marker ions allowing differentiation between the targeted isomeric compounds was established. Besides, interconversion of these isomers into one another was studied in the gas phase in conditions mimicking these processes in solution.

Application of Bacillus sp. strain VT-8 for decontamination of TNT-polluted sites

Bacterial strain Bacillus sp. VT-8 was shown to use trinitrotoluene (TNT) as the sole source of carbon, nitrogen, and energy, as well as to carry out its co-oxidation. Resistance of Bacillus sp. VT-8 to high TNT concentrations was shown. Efficient detoxification of TNT-contaminated soil and water samples was demonstrated. This strain may be recommended for TNT biodegradation at concentrations of up to 140 mg/L due to its high degradation activity and the absence of toxic effect of TNT on Bacillus sp. VT-8.

Molecular recognition of pseudodistamine isomeric precursors trans-3(4)-aminopiperidin-4(3)-ols by EI mass spectrometry

&NA; Synthesis of drugs, biologically active compounds or their derivatives always requires precise and reliable method of their identification, including differentiation of the possible isomers. Pseudodistamines and their precursors became a matter of elevated attention due to their different enzymatic inhibition. This paper deals with one of the groups of the pseudodistamine precursors − trans‐3(4)‐aminopiperidin‐4(3)‐ols. Their synthesis brings to a mixture of 2 regioisomers, resulting in the necessity of their reliable recognition. NMR spectroscopy commonly used by organic chemists requires advance knowledge and experience to analyse the spectra of these regioisomers. Therefore, we herein proposed a simpler way to recognize trans‐3(4)‐aminopiperidin‐4(3)‐ols using mass spectrometry with electron ionization. Fragmentation of 4 pairs of aminopiperidinol regioisomers with variation of amine moiety was studied. The obtained results allowed defining a group of 3 ions ([M‐18]+., [M‐19]+, [M‐43]+) related only to the structure of trans‐4‐aminopiperidin‐3‐ols and 1 ion (m/z 100) related to the structure of trans‐3‐aminopiperidin‐4‐ols. Besides, interrogation of intensity of ions common for spectra of both regioisomers allows making differentiation as well. Graphical abstract Figure. No caption available. HighlightsNew mass spectrometry approach for recognition of regioisomeric trans‐3(4)‐aminopiperidin‐4(3)‐ols was developed.Several marker ions related to the structure of different regioisomers were proposed.Fragmentation schemes for 4 pairs of trans‐3(4)‐aminopiperidin‐4(3)‐ols were proposed.

Regression algorithm for calculating second-dimension retention indices in comprehensive two-dimensional gas chromatography

Gas chromatography-mass spectrometry (GC-MS) is one of the most accurate, well developed, and reliable analytical tools for the analysis of volatile and semivolatile compounds. The GC-MS data have been extensively improved by enhancing the separation capacity via comprehensive two-dimensional gas chromatography (GC × GC). The reliability of the identification of the analytes in GC × GC-MS can be notably improved by applying the second-dimension retention index (2I) as additional analytical parameter along with the commonly used first dimension retention index (1I) and mass spectrum. A novel approach for calculating second-dimension retention indices (2I) for semivolatile organic compounds is proposed. It is noteworthy that the standards used in calculations are the same compounds recommended as internal standards by US EPA 8270 Method for analysis of semivolatile organic compounds. The new algorithm takes into account the analyte retention time and its retention temperature at the secondary column, (2tR) and (2TR), respectively. The experimental data collected with different primary oven temperature ramp rates and carrier gas flow rates have shown that the calculated by the proposed approach 2I values remain the same for each evaluated compound, drifting in a very narrow range. The proposed approach was tested using 100 organic compounds from various chemical classes including alkanes, phenols, nitrobenzenes, chlorinated hydrocarbons, anilines, polycyclic aromatic hydrocarbons (PAHs), phthalates, etc. The important advantage of the proposed 2I values for compounds of the same chemical origin (reference standards and analytes) involves applicability of well-known Lees indices for non-polar phases. Therefore, the proposed approach can be used in targeted and non-targeted analysis of a wide range of organic compounds. The reduced version of the second dimension retention indices provides a valuable mapping of the homologues series of organic compounds, making their detection and identification easy and reliable.