Download or read book New Approaches for the Chemical and Physical Characterization of Aerosols Using a Single Particle Mass Spectrometry Based Technique written by Matthew Todd Spencer and published by . This book was released on 2007 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comparison of mass spectra generated from petrochemical particles was made to light duty vehicle (LDV) and heavy duty diesel vehicle (HDDV) particle mass spectra. This comparison has given us new insight into how to differentiate between particles from these two sources.
Download or read book Analytical Chemistry of Aerosols written by Kvetoslav R. Spurny and published by CRC Press. This book was released on 2017-11-22 with total page 499 pages. Available in PDF, EPUB and Kindle. Book excerpt: Until the 1980s, researchers studied and measured only the physical properties of aerosols. Since the 80s, however, interest in the physicochemcal properties of aerosols has grown tremendously. Scientists in environmental hygiene, medicine, and toxicology have recognized the importance held by the chemical composition and properties of aerosols and the interactions of inhaled, "bad" aerosols. This book offers the first comprehensive treatment of modern aerosol analytical methods, sampling and separation procedures, and environmental applications, and offers critical reviews of the latest literature. This important field has developed rapidly in the last 15 years, but until now, no book effectively summarized or analyzed the existing research. Analytical Chemistry of Aerosols reviews procedures, techniques, and trends in the measurement and analysis of atmospheric aerosols. With contributions from acknowledged, international experts, the book discusses various methods of bulk analysis, single particle analysis, and the analysis of special aerosol systems, including fibrous and bacterial aerosols.
Download or read book Novel Techniques and Applications in Single Particle Mass Spectrometry written by John Francis Cahill and published by . This book was released on 2014 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the environment, aerosol particles can affect climate directly though scattering and absorbing radiation and indirectly by influencing cloud formation, albedo, and lifetime. Beyond the environment, aerosols are commonly used as a delivery mechanism for a variety of products, such as inhalers and spray paints. Chemically characterizing aerosols is a difficult endeavor, and relatively few instrumental methods are capable of doing so. A unique subset of instrumentation and techniques exist to measure aerosol chemical and physical properties. Among these, the aerosol time-of-flight mass spectrometer (ATOFMS) can measure single particle chemistry and size in real time. The ATOFMS was developed for the study atmospheric aerosols, and data acquired by the ATOFMS over the years since its creation has provided significant insight into many atmospheric phenomena; however, the application of this technique into disciplines other than atmospheric chemistry has been relatively unexplored. In this dissertation the ATOFMS is used in a conventional sense, to provide insight into atmospheric particle chemistry through two field studies in California, but also in an unconventional way by using the ATOFMS to answer outstanding questions in other disciplines, including nanomaterials and biochemistry. Often the chemistry of a single unit, rather than of the bulk, is needed in these disciplines, and the ATOFMS is uniquely suited to provide this information. The ATOFMS was used to chemically characterize single particles of a unique class of nanomaterials, called metal organic frameworks (MOFs), comprised of functionalized organic linkers and metal ions or metal ion clusters. ATOFMS data was able to show the presence of MOFs with mixed functionality, and show the exchange of functional groups between materials. Cell processes can be monitored by measuring small molecules that are part of cell metabolism, which can provide insight into cell functions, environment, and disease. Using an ATOFMS with a modified aerodynamic lens inlet, single microalgae cells 4-10 μm in diameter of various types have been be characterized. Compared to other single cell mass spectrometry techniques, the modified ATOFMS has unprecedented throughput, up to 50 Hz. Time-resolved measurements of cells undergoing nitrogen deprivation further highlight the abilities of the technique for single cell analysis.
Download or read book Aerosol Measurement written by Pramod Kulkarni and published by John Wiley & Sons. This book was released on 2011-09-09 with total page 1497 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosol Measurement: Principles, Techniques, and Applications Third Edition is the most detailed treatment available of the latest aerosol measurement methods. Drawing on the know-how of numerous expert contributors; it provides a solid grasp of measurement fundamentals and practices a wide variety of aerosol applications. This new edition is updated to address new and developing applications of aerosol measurement, including applications in environmental health, atmospheric science, climate change, air pollution, public health, nanotechnology, particle and powder technology, pharmaceutical research and development, clean room technology (integrated circuit manufacture), and nuclear waste management.
Download or read book Physical and Chemical Characterization of Individual Airborne Particles written by Kvetoslav Rudolf Spurny and published by Prentice Hall. This book was released on 1986 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fundamentals and Applications in Aerosol Spectroscopy written by Ruth Signorell and published by CRC Press. This book was released on 2010-12-20 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: Helping you better understand the processes, instruments, and methods of aerosol spectroscopy, Fundamentals and Applications in Aerosol Spectroscopy provides an overview of the state of the art in this rapidly developing field. It covers fundamental aspects of aerosol spectroscopy, applications to atmospherically and astronomically relevant problem
Download or read book New Chemical Aerosol Characterization Methods Examples Using Agricultural and Urban Airborne Particulate Matter written by Lijun Zhou and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study explored different chemical characterization methods of agricultural and urban airborne particulate matter. Three different field campaigns are discussed. For the agricultural aerosols, measurement of the chemical composition of size-resolved agricultural aerosols collected from a ground site at the nominally downwind and upwind edge of a feedlot in West Texas were reported. High volume cascade impactor samplers were used for the collection of the particles, and two major analytical methods were applied to characterize different components of the aerosols, ion chromatography (IC) was used to measure ionic composition with the main targets being ammonium (NH4), nitrate (NO3 - ), and sulfate (SO4 2- ), direct thermal desorption gas chromatography-mass spectrometry/flame ionization detection (GC-MS/FID) methodology was used to identify and quantify organic compounds in the aerosol particles. For the urban aerosols, I report the measurement of mass, and the chemical composition of size-resolved aerosols collected from two different locations in Houston, analyzed by the thermal desorption GC-MS/FID method. The investigation of single particle composition using RM is reported as well: RM and chemical mapping techniques have been applied for the qualitative analysis of components in the samples of air particulate matter collected in downtown Houston.
Download or read book Anthropogenic Particulate Source Characterization and Source Apportionment Using Aerosol Time of flight Mass Spectrometry written by Stephen Mark Toner and published by . This book was released on 2007 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods of measuring the chemical and physical properties of aerosols as well as proper source apportionment of ambient particles are necessary to provide insight as to the roles they play in the environment and their impact on human health. In addition, the ability to apportion ambient particles quickly and accurately will be very helpful for environmental and health agencies and for monitoring and enforcing emission standards by allowing such agencies to determine the primary source of aerosols in their monitoring areas. The goal of this dissertation is to provide a new approach for aerosol source apportionment using aerosol time-of-flight mass spectrometry (ATOFMS) single particle data. This goal was accomplished by determining unique mass spectral signatures for specific aerosol sources and by developing these signatures into a source signature library in which ambient ATOFMS data can be matched and apportioned. The creation of the source signature library (SSL) began with the characterization of specific sources themselves. Heavy duty diesel vehicle (HDDV) emissions were characterized using ATOFMS from a dynamometer study. The particle types detected for HDDVs were compared to those from a previous dynamometer study of gasoline powered light duty vehicles (LDV) to see if HDDV and LDV particles can be distinguished. A SSL was then created for the HDDV and LDV emissions to test the ability to properly apportion between the two sources on ambient ATOFMS data collected next to a major freeway using a SSL matching technique. This work demonstrated that the two sources are readily distinguishable in a fresh emission environment, and that the matching method is a valid means for apportioning ATOFMS data. The SSL was then extended for multiple specific sources as well as for non-source specific particles and was used to apportion the same freeway study particles; showing that the source matching method is able to accurately distinguish different particle sources and that there can be a large contribution from sources other than vehicles near a major freeway. Lastly, the SSL matching method was used to apportion ambient aerosols for two major non-US cities to show that the SSL matching technique is applicable to worldwide ambient ATOFMS data.
Download or read book Analysis of Atmospheric Aerosol Processes Using Single Particle Mass Spectrometry written by Jeffrey Robert Whiteaker and published by . This book was released on 2002 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Single Particle Characterization Source Apportionment and Aging Effects of Ambient Aerosols in Southern California written by Laura Grace Shields and published by ProQuest. This book was released on 2008 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Composed of a mixture of chemical species and phases and existing in a variety of shapes and sizes, atmospheric aerosols are complex and can have serious influence on human health, the environment, and climate. In order to better understand the impact of aerosols on local to global scales, detailed measurements on the physical and chemical properties of ambient particles are essential. In addition, knowing the origin or the source of the aerosols is important for policymakers to implement targeted regulations and effective control strategies to reduce air pollution in their region. One of the most ground breaking techniques in aerosol instrumentation is single particle mass spectrometry (SPMS), which can provide online chemical composition and size information on the individual particle level. The primary focus of this work is to further improve the ability of one specific SPMS technique, aerosol time-of-flight mass spectrometry (ATOFMS), for the use of identifying the specific origin of ambient aerosols, which is known as source apportionment. The ATOFMS source apportionment method utilizes a library of distinct source mass spectral signatures to match the chemical information of the single ambient particles. The unique signatures are obtained in controlled source characterization studies, such as with the exhaust emissions of heavy duty diesel vehicles (HDDV) operating on a dynamometer. The apportionment of ambient aerosols is complicated by the chemical and physical processes an individual particle can undergo as it spends time in the atmosphere, which is referred to as "aging" of the aerosol. Therefore, the performance of the source signature library technique was investigated on the ambient dataset of the highly aged environment of Riverside, California. Additionally, two specific subsets of the Riverside dataset (ultrafine particles and particles containing trace metals), which are known to cause adverse health effects, were probed in greater detail. Finally, the impact of large wildfires on the ambient levels of particulate matter in Southern California is discussed. The results of this work provide insight into single particles impacting the Southern California region, the relative source contributions to this region, and finally an examination of how atmospheric aging influences the ability to perform source apportionment.
Download or read book Source Profiling and Apportionment of Airborne Particles written by Philip Joseph Silva and published by . This book was released on 2000 with total page 904 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances and Applications of Mass Spectral Techniques for the Characterization of Atmospheric Aerosol Particles written by Lindsay Erighn Hatch and published by . This book was released on 2012 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerosol particles are ubiquitous in the atmosphere and induce significant impacts on human health and climate that depend on their physical and chemical properties, such as size, composition, and mixing state (chemical associations). Measurements of aerosol composition at the single-particle level are necessary to better understand these effects. Aerosol time-of-flight mass spectrometry (ATOFMS) is able to monitor the size and chemical composition of individual particles in real time. In this doctoral research, ATOFMS analysis was extended to identify new mass spectral markers and improve the potential for quantitative measurements. Development of novel instrumentation was also undertaken. Ion markers indicative of organosulfate compounds were identified in ATOFMS mass spectra collected in Atlanta, GA. In this study, the mixing state and temporal behavior of particulate organosulfate compounds were observed for the first time. Organosulfates were overwhelmingly detected in carbonaceous submicron particles and the temporal trends indicated that they likely formed by the daytime oxidation of isoprene followed by aqueous reaction with sulfate overnight. These results highlight the roles of mixing state and multi-phase reactivity on the formation of secondary organic aerosols. ATOFMS measurements of thermally-conditioned aerosol residuals obtained during the 2005 Study of Organic Aerosols in Riverside, CA were analyzed to determine the impacts of atmospheric aging on the laser desorption/ionization process. Coatings of secondary species suppressed the ionization efficiency, thereby impacting the mass spectral peak areas; however, a novel analysis method was found to correct these artifacts and produced strong agreement with collocated quantitative instrumentation. This new analysis technique was then applied to investigate the mixing-state dependence of aerosol volatility observed in Riverside. It was observed that particulate nitrate evaporated at different temperatures from different particle types (e.g., organic vs. biomass burning), which may influence the regional transport of nitrate species. ATOFMS provides important insights into size-resolved particle sources; however it heavily fragments most organic species, resulting in loss of the molecular information. Therefore, a novel chemical ionization mass spectrometer was developed to better characterize the molecular organic aerosol constituents. In particular, an ion funnel was incorporated into a home-built proton-transfer-reaction mass spectrometer. Initial characterization studies and ion simulations indicated that the ion funnel can provide high-efficiency ion transfer from the ionization region to the mass spectrometer. These results demonstrate the potential for this instrument to ultimately achieve highly sensitive analyses of organic aerosols.
Download or read book Understanding the Chemistry of Atmospheric Particles Using Single Particle Mass Spectrometry written by Maria Anna Zawadowicz and published by . This book was released on 2017 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis explores ways in which single particle mass spectrometry can be extended, whether through hardware improvements, or through the use of advanced data processing techniques to provide new kinds of aerosol chemistry measurements. Most of this work has been carried out using the Particle Analysis by Laser Mass Spectrometry (PALMS) instrument, an aircraft deployable mass spectrometer that uses intense (~10^9 Wcm^-2 ) UV laser pulses to vaporize and ionize single particles and measures their mass spectra using a time-of-flight mass spectrometer. Near-term and long-term hardware improvements as well as advanced data analysis techniques are explored in order to extract new chemical information from the thus obtained single particle mass spectra. Hardware improvements to PALMS are explored, such as the use of a high-powered femtosecond laser to obtain single particle mass spectra and a new high resolution compact mass analyzer. Also, a new commercial mass spectrometer LAAPToF is characterized and compared to PALMS. In addition to hardware improvements, novel data analysis techniques for analysis of single particle mass spectra were developed as a part of this work. In particular, a new method to identify biologically-derived particles is presented and used to derive vertical profiles of bioaerosol from near-surface to the upper troposphere.
Download or read book Using Mass Spectrometry and Ftir to Characterize Atmospherically relevant Particles Generated in Laboratory Systems written by Emily Anne Bruns and published by . This book was released on 2011 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric aerosols are known to have multifaceted effects on human health, visibility and climate. To understand these effects, characterization of aerosol properties is necessary. This dissertation focuses on several specific topics with the overall goal of improving our understanding of aerosols in the atmosphere. One area of importance is particulate organic nitrates, which are known to be ubiquitous in the atmosphere; however, there is a lack of proven analytical techniques for their measurement. The qualitative and quantitative response of a high resolution time of flight aerosol mass spectrometer to particulate organic nitrates was studied by analyzing secondary organic aerosol (SOA) from NO3 radical reactions with [Alpha]- and [Beta]-pinene, 3-carene, limonene, and isoprene. Extensive fragmentation of the organic nitrate products was observed in the mass spectra, which precluded molecular speciation. Another area of interest is the recent development of a number of ambient ionization techniques, which are promising for aerosol characterization. One such technique, atmospheric solids analysis probe mass spectrometry (ASAP-MS), was applied for the first time to the identification of organics in SOA, which was generated in the laboratory from the ozonolysis of & alpha;-pinene and isoprene, and from the NO3 oxidation of & alpha;-pinene. Also, ambient samples were collected from a forested and a suburban location. ASAP-MS data for the laboratory-generated samples showed peaks corresponding to well-known products of these reactions, and higher molecular weight oligomers were present in all samples. This is consistent with previously published studies of similar systems and shows that ASAP-MS should have wide applicability in both laboratory and field studies. Vapor pressures of low volatility compounds are important parameters in several atmospheric processes, including the formation of new particles and the partitioning of compounds between the gas-phase and particles. However, vapor pressures of low volatility compounds are challenging to measure and reported values vary significantly, illustrating the need for new approaches. ASAP-MS was applied for the first time to the measurement of vapor pressures and heats of sublimation. The measured heats of sublimation were in good agreement with published values. The vapor pressures were typically within a factor of three of published values made at similar temperatures. This study establishes that ASAP-MS is a promising new technique for vapor pressure and heat of sublimation measurements of low volatility compounds. To further understand new particle formation, laboratory and field measurements were made to identify gas-phase amines, which could play a role in new particle formation, from previously unknown sources using proton transfer reaction mass spectrometry. The work presented in this dissertation advances our understanding of aerosols and explores novel methods for their characterization.
Download or read book A Machine learning Approach to Aerosol Classification for Single particle Mass Spectrometry written by Costa D. Christopoulos and published by . This book was released on 2017 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compositional analysis of atmospheric and laboratory aerosols is often conducted via single-particle mass spectrometry (SPMS), an in situ and real-time analytical technique that produces mass spectra on a single particle basis. In this study, machine learning classification algorithms are created using a dataset of SPMS spectra to automatically differentiate particles on the basis of chemistry and size. While clustering methods have been used to group aerosols into broad categories based on similarity, these models do not incorporate known aerosols labels and are not explicitly formulated for classification. Furthermore, traditional methods often rely on a smaller set of well-known, important variables whereas the proposed method is more general and flexible, allowing researchers to automatically quantify and select important variables from any aerosol subset. In this work, machine learning algorithms build a predictive model from a training set in which the aerosol type associated with each mass spectrum is known. Several such classification models were created to differentiate aerosol types in four broad categories: fertile soils, mineral/metallic particles, biological, and all other aerosols using -40 common positive and negative spectral features. For this broad categorization, machine learning resulted in a classification accuracy of -93%. More complex models were developed to classify aerosols into specific categories which resulted in a classification accuracy of -87%. The trained model was then applied to a 'blind' mixture of aerosols with model agreement on the presence of secondary organic aerosol, coated and uncoated mineral dust and fertile soil. Additionally, the model is used to characterize an ambient atmospheric dataset collected from the free troposphere.
Download or read book The Characterization of Atmospheric Aerosols written by and published by . This book was released on 1998 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project of the Los Alamos National Laboratory (LANL). The objective of this collaborative research project is the measurement and modeling of atmospheric aerosols and heterogeneous (gas/aerosol) chemical reactions. The two major accomplishments are single particle characterization of tropospheric particles and experimental investigation of simulated stratospheric particles and reactions thereon. Using aerosol time-of-flight mass spectrometry, real-time and composition measurements of single particles are performed on ambient aerosol samples. This technique allows particle size distributions for chemically distinct particle types to be described. The thermodynamics and chemical reactivity of polar stratospheric clouds are examined using vapor deposited thin ice films. Employing nonlinear optical methods, as well as other techniques, phase transitions on both water and acid ices are monitored as a function of temperature or the addition of gases.
Download or read book Development and Use of Particle Into Liquid Sampling Time of flight Mass Spectrometry PILS ToF for Characterization of Aerosol Particles written by Christopher Holmes Clark and published by . This book was released on 2012 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation introduces and makes use of the Particle-into-Liquid-Sampler coupled to a Time-of-Flight mass spectrometer (PILS-ToF), a new instrumental method used here to provide new chemical characterization information on secondary organic aerosol (SOA). The PILS-ToF instrument improves upon drawbacks found in current state-of-the-art mass spectral chemical characterization methods to include lack of time resolution and ion fragmentation by electron impact ionization in the Aerodyne Aerosol Mass Spectrometer (AMS). The functionality of the PILS-ToF for collection and response to SOA particle formation is validated against a scanning mobility particle sizer (SMPS), a widely accepted and standardized physical chemical characterization instrument, for a well characterized SOA formation experiment, dark ozonolysis of [alpja]-pinene. The PILS-ToF is also used to lend insight into oligomer growth during the NO photo-oxidation of isoprene. It is of atmospheric importance to study SOA formation from isoprene as it is globally the most abundant non-methane hydrocarbon in the ambient. SOA from isoprene is further studied using the PILS-ToF as part of the suite instrumentation at the University of California, Riverside, College of Engineering, Center for Environmental Research and Technology (CE-CERT) atmospheric chamber providing a complete chemical and physical characterization of SOA formed by isoprene with various oxidants under a myriad of oxidant concentration conditions. In addition, the PILS-ToF is used, again in tandem with other chemical and physical characterization methods at CE-CERT, to probe temperature effects on SOA formation from isoprene under many different oxidizing conditions. Finally, the PILS-ToF is used to provide new mechanistic information on SOA formation from trimethylamine and tributylamine, two tertiary amines emitted from anthropogenic and animal husbandry processes. For these two teriary amines the PILS-ToF provides evidence of oligomerization giving a potential explanation to the high SOA yields from these parent compounds.
