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NMR Aerosolomics Study of Water-Soluble Organic Compounds in Size-Resolved Particulate Matter
Horník, Štěpán ; Vodička, Petr ; Pokorná, Petra ; Schwarz, Jaroslav ; Ždímal, Vladimír ; Sýkora, Jan
Organic aerosols (OA) account for a significant fraction (10 – 90%) of atmospheric particulate matter (Hallquist et al., 2009). The composition of organic aerosols is very complex and is usually characterized by their water solubility. Water-soluble organic compounds (WSOC) constitute a large fraction of OA (10 – 80%) and consist of chemical species containing oxygenated functional groups such as hydroxyl, carboxyl, or carbonyl groups. NMR spectroscopy represents an alternative to commonly used techniques (gas chromatography-mass spectrometry, liquid chromatography-based techniques) for WSOC analysis. Our recently introduced method, called NMR aerosolomics, allows quantitative analysis of dozens of individual compounds from different aerosol samples. An important part of the characterization of aerosols is their classification by particle size. The analysis of individual compounds in the size-resolved fractions of the WSOC class has been performed only in a few studies that focus mainly on a particular subclass of compounds or use multiple analytical techniques.
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NMR Aerosolomics as a Tool to Distinguish Various Types of Aerosols.
Horník, Štěpán ; Schwarz, Jaroslav ; Ždímal, Vladimír ; Sýkora, Jan
Water-soluble organic compounds represent up to 80% of all organic compounds present in atmospheric aerosols. Unlike composition of inorganic compounds or volatile organic compounds, which seems to be well explored, the knowledge about WSOC composition is still rather limited. The most frequently used method for WSOC analysis is GC-MS, which is a very sensitive technique. However, the analysis of polar compounds via GC-MS requires derivatization and the quantification is extremely time consuming. The second widely used technique is ion chromatography (IC). Nowadays, IC is routinely used for analysis of specific groups of organic compounds such as carboxylic acids, amines or carbohydrates. On the other hand, there is NMR spectroscopy as a fully quantitative but rather insensitive method. NMR spectroscopy was for the purpose of aerosol chemistry employed only recently as this technique has undergone rapid development and sensitivity gain of late. So far, the use of NMR spectroscopy is mainly restricted to socalled Functional Group Analysis, of which main interest lies elsewhere than in identification of individual compounds.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22019110512330 - PDF
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NMR Aerosolomics: A Convenient Route to Organic Aerosol Analysis.
Horník, Štěpán ; Schwarz, Jaroslav ; Sýkora, Jan
Atmospheric aerosols are a small but very important part of the Earth’s atmosphere. The proportion of inorganic and organic compounds in aerosol particles seems to be equal on average. While the inorganic composition of aerosols is well explored, knowledge about the organic part is still very limited. It is well known that the major part of organic aerosol compounds is represented by polar, water-soluble organic compounds (WSOC). So far GC-MS is the most frequently used method for WSOC analysis. GC-MS is a very sensitive technique, furthermore, it exploits huge spectra libraries accumulated over decades. Therefore, its role in the determination of aerosol composition is indisputable. Primarily owing to GC-MS, about 150 organic compounds have been identified in aerosol particles. NMR spectroscopy for the purpose of aerosol chemistry was discovered only recently as it is rather insensitive method. Nevertheless, NMR has undergone rapid development and sensitivity gain of late. Moreover, it is fully quantitative method and no sample derivatization is needed. So far, the use of NMR spectroscopy has been limited to so called Functional group analysis. In this analysis the whole NMR spectrum is divided into parts and subsequently integrated according to functional groups.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22018110212472 - PDF
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