Members of the Faculty of Chemistry of the Lomonosov Moscow State University have elaborated a new approach to monitor the environmental status in Moscow, with the help of which one could detect larger quantity of environmental components and so enlarge the list of substances, possessing environmental and human health hazard. The project results have been published in the Environmental Pollution journal.
Assessment of the environmental status and, in particular, atmosphere, in Moscow reduces to detection of several scores of nonorganic and organic substances by fixed-site laboratories, subordinate to Mospriroda. However, ecological laboratories don't monitor all beyond this short list. The Lomonosov Moscow State University scientists have detected novel pollutants in Moscow air with the help of gas chromatography-mass spectrometry analysis.
Albert Lebedev, Doctor of Chemistry, Professor at the Organic Chemistry Department at of the Faculty of Chemistry of the Lomonosov Moscow State University and the article author shares: "The main project result is the enlargement of the list of determined substances and detection of novel ones, posing potential environmental and human health hazard. Composition of organic air pollutions is not stable so it's important to monitor regularly in order to provide early recognition of new threats both to the city ecosystem and citizens' health". The scientist has noticed that monitoring is useful for many purposes. First of all, due to it one could get update information about the subject, namely water, soil, atmosphere. Secondly, with the help of monitoring one could detect the source of a hazardous substance and eliminate it and, consequently decrease the level of in-going pollutants. After elimination of this source one could apply methods of treatment and "green" technologies as additional protection means.
Scientists deal with targeted as well as with non-targeted analyses. The latter implies looking for as many substances as possible. Targeted analysis is a purposeful detection of compounds, known in advance. All analyses are made on snow samples, collected for research by scientists. In this connection this monitoring method is applicable only for cold-climate areas and mountains. This method could be applied all over Russia as the climate almost nationwide is with prominent alternation of seasons. However, one should take into consideration that pollution picture could strongly vary in different regions.
The basic technique, used by scientists in their research, is gas chromatography-mass spectrometry analysis (GC-MS). It's a single device, elaborated as a result of combination of two analytical approaches. Gas chromatography is used for separation of organic compounds, which after that run into a mass-spectrometer one by one, where ionization and fragmentation take place. As a result, each individual substance is characterized by mass-spectrum, which allows to elucidate its structure. Mass-spectrum of any substance is unique, what makes possible to use computer libraries. As a result of gas chromatography-mass spectrometry analysis one gets a diagram of dependence of signal intensity on time (a chromatograph), where each identified substance is represented by a separate peak, whose area is proportional to its quantity in the mixture. So as a result of this technique application an unknown mixture, consisting of hundreds of compounds, evolves into the full profile information. Mass spectrometry has proved to be the most informative, sensitive, reliable and fast analytical technique, which could be applied also for environmental studies. Modern mass spectrometry is able toidentify the nature of unknown ecotoxicants among a wide range of other compounds, even though these ecotoxicants are represented in traces. Today it's the basic method, used for environmental control of any environmental objects.
With the help of this novel technique the list of substances, detected in Moscow environment, gets much larger in comparison with other laboratories. But at the moment scientists focus on volatile and semi-volatile compounds, which could be analyzed by the GC-MS technique. Consequently, among known hazardous categories of ecotoxicants chemists are able to detect phenols, phthalates, organochlorine compounds, pesticides, polycyclic aromatic hydrocarbons. Albert Lebedev notices: "We don't deal with detection of compounds' toxicity. It's the domain of toxicologists. Any substance is toxic; the question is only in its concentration. Depending on the structure of compounds their toxicity varies in a very wide range: from grams to femtograms. Today the most hazardous ones are polychlorinated dibenzodioxins and dibenzofurans, polychlorinated biphenyls, benz[a]pyrene, some pesticides. However, following the increase of novel substances in environmental objects, the list of the most hazardous ones could be enlarged."
The scientist sums up: "Detection of novel potentially hazardous substances in the environment is crucially important for conservancy of natural ecosystems and human health concerns. Transfer of these data provides deeper understanding of pollution nature and allows effective detection of contamination sources. Scientific value of the project lies in enlargement of mass spectrometry usage. Besides that, the project assists in elaboration of protocols for identification of organic substances in difficult, multicomponent matrixes, whose composition is hardly known. For instance, one could name samples of snow, ice, water of various types: sea, drinking, fresh, waste water and cloud water, phytogenous extracts, food, beverages, cosmetics, industrial products, amphibians' secretion, etc."
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Journal
Environmental Pollution