The integral methods commonly used to determine oil products, such as gravimetric, IR-photometric, and fluorescent do not take into account the nature of the analyzed compounds and the contribution of biogenic hydrocarbons, the assessment of which requires more detailed analysis, which can be made by GC/MS method. The oil products in Lake Pyasino bottom sediments show the presence of n-alkanes with a considerable predominance of C17 n-alkane and a small predominance of n-C 12 , n-C 14 , n-C 16 , and n-C 18 , reflecting the contribution of microorganisms and algae, as well as the predominance of n-C 23 , n-C 25 , n-C 27 , n-C 29 , n-C 31 due to the contribution of higher terrestrial plants. The chromatogram contains two “humps” of nonseparated compounds in the C 10 −C 21 and C 22 −C 33 regions. Oil products in them are mixtures of alkanes, cycloalkanes with 1–4 rings in a condensed system, and aromatic and naphthene-aromatic hydrocarbons with 1–3 benzol and 1–2 saturated rings in the condensed system, with alkyl substituents containing 0–12 (mostly, 2–8) C atoms.

Dioxin contamination levels and profiles of soils in New Moscow area were studied to identify the potential sources of contamination at a distance of 300 to 1000 m from the former Salar’evo, Shcherbinka, Sosenki, and Malinki landfills. The potential sources are derived using principal component analysis and positive matrix factorization. The total contamination level near the landfills does not significantly differ from those of urban soils in the same area. The congener profiles correspond to a combination of several dioxin contamination sources, including atmospheric deposition, various thermal processes, and spill of polychlorinated biphenyl technical fluids. A higher relative contribution of vehicle exhaust is characteristic of urban soils. As for the soils near former landfills, the congener profiles are more variable as well as, consequently, sources of contamination.

Analysis of the composition of crude oils from four oil and gas basins by gas chromatography–mass spectrometry has shown that aromatic compounds bearing a phenyl substituent are as typical of oils as the well-known phenanthrenes and chrysenes. Thus, biphenyls are the first member of the series of compounds of this structural type. Unsubstituted and alkyl substituted phenylnaphthalenes, terphenyls, phenylphenanthrenes, and naphthylnaphthalenes have been identified; the smallest set of components of this type (only phenylnaphthalenes) is in Volga–Urals oils. Unlike the case of dispersed organic matter (OM), the main components in oils are alkyl substituted compounds, which can have as long substituents as C10 alkyls in some cases. The proportion of unsubstituted compounds is small. In all the oils, thermodynamically more stable isomers predominate. The phenylnaphthalene content is close to the content of chrysenes, the proportion of which is about an order of magnitude lower than that of phenanthrenes. In one of the samples, phenylnaphthalenes are about in the same amount as phenanthrenes. The total concentration of terphenyls, phenylphenanthrenes, and naphthylnaphthalenes is usually much lower than the concentration of phenylnaphthalenes. To date, the use of phenyl substituted aromatic compounds in geochemistry has been limited to oil–oil and oil–OM correlations. Studying compounds of this type is important both for more detailed characterization of the composition of aromatic compounds of crude oil and for understanding the processes of oil generation in different environments.

We developed a sample preparation method for the determination of polybrominated diphenyl ethers (PBDEs) with from one to ten bromine atoms in samples of feed and food products containing approximately 0.5 g of animal fat or vegetable oil. The method involves gas chromatography with high-resolution mass spectrometry or tandem mass spectrometry. A possibility of using various reagents for the purification of extracts by chemical reactions and fractionation is studied. The physicochemical properties of PBDEs and polychlorinated biphenyls (PCBs) have significant differences, and to determine the full range of PBDEs, it is necessary to use other methods of sample preparation than in the case of PCBs. The conditions selected for the purification of extracts in a column filled with potassium silicate, Florisil, and silica impregnated with sulfuric acid and for their fractionation using activated neutral alumina ensure the PBDE recoveries of at least 75%. Purification of the extracts can be carried out without the use of chlorinated organic solvents. Applied aspects of instrumental analysis and measurement quality assurance are also described.

A new method for determination of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in fats based on the use of Carboxen 1000 and 1016 sorbents has been proposed. The use of Carboxen 1000 obviates the stage of chemical degradation of the fat matrix, thus providing high quality of the extract purification at shorter sample preparation times and a relatively small solvent consumption. The recovery values were slightly lower than in common methods of sample preparation but, nonetheless, conformed to the criteria of Russian and foreign standard methods. The method can be used to analyze animal fats and vegetable oils from food and animal feeds.

The values of the benzo(a)pyrene total toxicity equivalent (B(a)P-TEQ) of polycyclic aromatic hydrocarbons (PAHs) in the surface layers of Moscow soils are given in this paper. The value of B(a)P-TEQ for eight potentially carcinogenic PAHs in soils ranges from 14.1 to 1995.6 μg/kg with an average value of 299.4 μg/kg and a median of 132.8 μg/kg. In the functional zones of the city, the greatest value of B(a)P-TEQ in soil is observed in the residential and transport areas, while the administrative districts with the highest level are the Southeastern and Central districts. The main contribution to the total toxicity equivalent of PAHs is made by dibenz(a,h)anthracene and benzo(a)pyrene. For 85% of the analyzed soils in the city, the value of 8B(a)P-TPQ is <600 μg/kg, which, according to the Canadian Ministry of Ecology, corresponds to a carcinogenic risk for a person of less than 10–6. For 15% of soils, this indicator lies in the range of 775.6–1995.6 μg/kg, which corresponds to risk in the range of 10–6–10–5.

Gas chromatography with mass spectrometric detection was used to analyze bitumens isolated from bottom sediments of peat lakes contaminated with petroleum products. Endogenous hydrocarbons are characterized by the presence of n-alkanes with an odd number of carbon atoms in the molecule in the characteristic region of C23–C33, the absence of a “hump” characteristic of oil products in the chromatogram, and the presence of light hydrocarbons, eluting in the initial part of the chromatogram (light hydrocarbons are usually lost when the sample is dried). The distribution profile of odd n-alkanes is used to assess the contribution of endogenous hydrocarbons to the “hydrocarbon index” with the help of the pattern recognition method. The concentration of light hydrocarbons is from 50 and 300–400 to 3500–5000 mg/kg for a number of samples and even up to 26000 mg/kg in some samples. The concentration of petroleum hydrocarbons and heteroatomic compounds varies from the lowest values of 30–80 mg/kg up to 20000 mg/kg and higher.

A comparative analysis of three methods of PCB determination in insulating fluids is carried out using capillary gas chromatography with a detection by electron capture (GC-ECD — IEC 61619:1997 »Insulating liquids – Contamination by polychlorinated biphenyls (PCB) – Method of determination by capillary column gas chromatography; EN 12766-2:2001 «Petroleum products and used oils – Determination of PCBs and related products»; FR 1.31.2012.13568 «Method for determination of sum of polychlorinated biphenyls and sum of polychlorinated terphenyls in mineral and synthetic oils, petroleum products and wastes by capillary column gas chromatography»). The first method requires determination of all the congeners in the analyzed sample and encounters the impossibility of their identification at the relatively low content of congeners and interfering impact of the impurities present in the used oils. The second method based on determination of six selected congeners (28, 52, 101, 153, 138, and 180) and subsequent multiplying of the sum of their contents by a factor of 5 is much better, but does not provide evaluation of the accuracy of the results thus obtained. The third method based on the use of technical products for calibration, and an arbitrary number of congeners distributed throughout the elution interval for determination of the content and type of the technical product occupies an intermediate position in comparison with the two previously considered methods and provides estimation of the uncertainty of the result. This method gives an intermediate result in comparison with the two previous ones and allows us to estimate the uncertainty of the result.

We compared data on the extent of bioremediation in soils polluted with oil. The data were obtained using conventional methods of hydrocarbon determination: extraction gas chromatography-mass spectrometry, extraction IR spectroscopy, and extraction gravimetry. Due to differences in the relative abundances of the stable carbon isotopes (13C/12C) in oil and in soil organic matter, these ratios could be used as natural isotopic labels of either substance. Extraction gravimetry in combination with characteristics of the carbon isotope composition of organic products in the soil before and after bioremediation was shown to be the most informative approach to an evaluation of soil bioremediation. At present, it is the only method enabling quantification of the total petroleum hydrocarbons in oil-polluted soil, as well as of the amounts of hydrocarbons remaining after bioremediation and those microbially transformed into organic products and biomass.

Проведен сравнительный анализ данных, полученных с использованием стандартных методов количественного определения углеводородов (экстракционный газо-хромато-масс-спектрометрический, экстракционный ИК-спектроскопический и экстракционно-гравиметрический), которые позволяют оценить степень биоремедиации почв, загрязненных нефтью. Различия в распределении стабильных изотопов углерода (13С/12) нефти и почвенного органического вещества были использованы в качестве природной изотопной “метки” этих веществ. Показано, что при оценке степени биоремедиации почв наиболее информативным методическим подходом является экстракционно-гравиметрический метод в сочетании с характеристиками изотопного состава углерода органических продуктов в почве до и после биоремедиации. В настоящее время этот подход можно рассматривать как единственный метод, который позволяет определить общее количество углеводородов и почвенного органического вещества в загрязненной нефтью почве, а также их содержание, остававшееся в почве после биоремедиации, и количество углеводородов, трансформированных микроорганизмами в органические продукты.

The potential use of gas chromatography/electron ionization mass spectrometry with high-energy electrons for detailed type analysis of heavy distillates and residual petroleum products has been shown. The method is based on the selection of characteristic ions corresponding to certain structural groups in the mass spectra presented as tables of homologous-series ions. In a set of ion mass chromatograms of a homologous series, these ions produce chromatographic peaks that can be represented as sections of a certain three-dimensional pseudo-peak. These three-dimensional peaks characterize both mass and retention time intervals for characteristic ions of compounds of a particular type. The overlap of the characteristic ion peaks of a given type of compounds with other types is much less than in the absence of chromatographic separation, since it is limited to compounds that elute in the given interval of retention times. The contribution of each group of compounds to the total ion current is determined from the sum of abundances of characteristic ions with allowance for the overlap of the mass spectra and differences in the ionization efficiency. The type analysis by this method can be performed without preliminary separation into saturates and aromatics.

Показана возможность использования газовой хроматографии/масс-спектрометрии с электронной ионизацией при высоких энергиях электронов для детального определения группового состава тяжелых и остаточных нефтепродуктов. Метод основан на выделении в масс-спектрах, представленных в виде таблиц гомологических рядов ионов, характеристических ионов, соответствующих определенным структурным группам соединений. На серии масс-хроматограмм ионов гомологического ряда эти ионы образуют хроматографические пики, которые могут быть представлены как сечения некоторого псевдо-трехмерного пика. Эти трехмерные пики характеризуют как интервалы масс, так и интервалы времен удерживания характеристических ионов групп соединений. Наложения на пики характеристических ионов данной группы соединений со стороны других групп гораздо меньше, чем в отсутствие хроматографического разделения, так как ограничиваются только соединениями, элюирующимися в данном интервале времен удерживания. По суммам пиков характеристических ионов с учетом взаимных наложений масс-спектров и различий в эффективности ионизации определяется вклад в ПИТ каждой группы соединений. Определение группового состава этим методом может производиться без предварительного разделения на насыщенную и ароматическую части.

Conditions for the preparation and extraction of some phenol ester derivatives with isopropyl chlorofomate are optimized for their subsequent determination by gas chromatography-mass spectrometry. The degrees of conversion into corresponding derivatives for phenol, 3-methylphenol, 3,4-dimethylphenol, 4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, 3,4-difluorophenol, 3-chloro-4-fluorophenol, 4-iodophenol, β-naphthol, α-naphthol, and pentachorophenol are in the range 90–100%. The limits of detection range from 200 ng/L (4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol) to 1.5 μg/L (pentachlorophenol).

The type composition of oil and oil products is usually determined by either the summation of all individuals of this compound type found from GC or GC/MS data or using appropriate generalized analytical features specific for a compound type as a whole. The specific representation of mass spectra of a complex mixture as a table of 14 homological series allows the analyst to visualize characteristic ion clusters specific for the compound types. These ion clusters form a “type mass spectrum” for each compound type. In the mass chromatograms of ions of a homologous ion series, these ion clusters form peculiar three-dimensional chromatographic peaks, whose width along the retention time axis corresponds to the isomer distribution for the homologue, molecular mass distribution (if molecular ions are considered), or structural features of the system of fused rings (for fragment ions) and “volume,” the concentration of the compound type. Three-dimensional chromatographic peaks for compound types are similar to usual peaks for individual compounds in ion mass chromatograms.

Оптимизированы условия получения и экстракции эфирных производных некоторых фенолов с изопропилхлороформиатом для их последующего определения методом, сочетающим газовую хроматографию и масс-спектрометрию. Для фенола, 3-метилфенола, 3,4-диметилфенола, 3-метилфенола, 4-хлорфенола, 2,4-дихлорфенола, 2,4,6-трихлорфенола, 3,4-дифторфенола, 3-хлор-4-фторфенола, 4-иодфенола, -нафтола, -нафтола, пентахлорфенола степень превращения в соответствующие производные составляет 90–100%. Пределы обнаружения составляют от 200 нг/л (4-хлорфенол, 2,4-дихлорфенол, 2,4,6-трихлорфенол) до 1.5 мкг/л (пентахлорфенол).

The distribution of different homological groups of polychlorinated biphenyls (PCBs) in the urbanozem profile of the arboretum in the Botanical Garden of Moscow State University has been considered. The levels of their content, the composition of a congener spectrum, potential sources, and the ecotoxicological impact of soil pollution are assessed. The maximal concentrations of di-, tri-, and tetrachlorbiphenyls are observed in the technogenic layer of soil at a depth of 20–40 cm (0.30, 0.44, and 24.25 μg/kg, respectively), and penta- and hexachlorbiphenyls in the surface humus layer (42.33 and 17.89 μg/kg, respectively). The content of hepta- and oñtachlorbiphenyls varies insignificantly with increasing the depth (0.67–1.25 and 0.15–0.41 μg/kg, respectively). Penta- and hexachlorbiphenyls contribute most to the spectrum of PCBs in urbanozem.