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Kahle EM, Zarnkow M, Jacob F. Beer Turbidity Part 2: A Review of Raman Spectroscopy and Possible Future Use for Beer Turbidity Analysis. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2020. [DOI: 10.1080/03610470.2020.1800345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Eva-Maria Kahle
- Forschungszentrum Weihenstephan für Brau- und Lebensmittelqualität, Technische Universität München, Alte Akademie 3, 85354 Freising-Weihenstephan, Germany
| | - Martin Zarnkow
- Forschungszentrum Weihenstephan für Brau- und Lebensmittelqualität, Technische Universität München, Alte Akademie 3, 85354 Freising-Weihenstephan, Germany
| | - Fritz Jacob
- Forschungszentrum Weihenstephan für Brau- und Lebensmittelqualität, Technische Universität München, Alte Akademie 3, 85354 Freising-Weihenstephan, Germany
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2
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Tascon M, Alam MN, Gómez-Ríos GA, Pawliszyn J. Development of a Microfluidic Open Interface with Flow Isolated Desorption Volume for the Direct Coupling of SPME Devices to Mass Spectrometry. Anal Chem 2018; 90:2631-2638. [PMID: 29388761 DOI: 10.1021/acs.analchem.7b04295] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Technologies that efficiently integrate the sampling and sample preparation steps with direct introduction to mass spectrometry (MS), providing simple and sensitive analytical workflows as well as capabilities for automation, can generate a great impact in a vast variety of fields, such as in clinical, environmental, and food-science applications. In this study, a novel approach that facilitates direct coupling of Bio-SPME devices to MS using a microfluidic design is presented. This technology, named microfluidic open interface (MOI), which operates under the concept of flow-isolated desorption volume, consists of an open-to-ambient desorption chamber (V ≤ 7 μL) connected to an ionization source. Subsequently, compounds of interest are transported to the ionization source by means of the self-aspiration process intrinsic of these interfaces. Thus, any ionization technology that provides a reliable and constant suction, such as electrospray ionization (ESI), atmospheric-pressure chemical ionization (APCI), or inductively coupled plasma ionization (ICP), can be hyphenated to MOI. Using this setup, the desorption chamber is used to release target compounds from the coating, while the isolation of the flow enables the ionization source to be continuously fed with solvent, all without the necessity of employment of additional valves. As a proof of concept, the design was applied to an ESI-MS/MS system for experimental validation. Furthermore, numerical simulations were undertaken to provide a detailed understanding of the fluid flow pattern inside the interface, then used to optimize the system for better efficiency. The analytical workflow of the developed Bio-SPME-MOI-MS setup consists of the direct immersion of SPME fibers into the matrix to extract/enrich analytes of interest within a short period of time, followed by a rinsing step with water to remove potentially adhering proteins, salts, and/or other interfering compounds. Next, the fiber is inserted into the MOI for desorption of compounds of interest. Finally, the volume contained in the chamber is drained and moved toward the electrospray needle for ionization and direct introduction to MS. Aiming to validate the technology, the fast determination of selected immunosuppressive drugs (e.g., tacrolimus, cyclosporine, sirolimus, and everolimus) from 100 μL of whole blood was assessed. Limits of quantitation in the subppb range were obtained for all studied compounds. Good linearity (r2 ≥ 0.99) and excellent precision, with (8%) and without (14%) internal standard correction, were attained.
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Affiliation(s)
- Marcos Tascon
- Department of Chemistry, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - Md Nazmul Alam
- Department of Chemistry, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | | | - Janusz Pawliszyn
- Department of Chemistry, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
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Pacenti M, Lofrumento C, Dugheri S, Zoppi A, Borsi I, Speranza A, Boccalon P, Arcangeli G, Antoniucci A, Castellucci E, Cupelli V. Physicochemical Characterization of Exhaust Particulates from Gasoline and Diesel Engines by Solid-Phase Micro Extraction Sampling and Combined Raman Microspectroscopic/Fast Gas-Chromotography Mass Spectrometry Analysis. EUR J INFLAMM 2017. [DOI: 10.1177/1721727x0900700104] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Ambient Particulate Matter (PM) has been shown to be associated with cardiopulmonary diseases and lung cancer. Several groups of investigators have shown that the size of the airborne particles and their surface area determine the potential to elicit inflammatory injury and other mechanisms of adverse cellular effects. Because traffic is an important source of PM, it seems obvious that physicochemical characterization of vehicles exhaust emission has an important impact on both quantitative and qualitative aspects of ambient PM. In the present study the exhaust emissions of 8 vehicles of different categories were analyzed to attempt to differentiate them. For such purpose the particulate was collected on SPME fibers exposed to the exhaust emission for 150 s. The particulate was first characterized by micro-Raman spectroscopy and then subjected to Fast Gas Chromatography-Mass Spectrometry analyses for the chemical identification of the Polycyclic Aromatic Hydrocarbons (PAHs) compounds, the organic fraction of particulate matter in air pollution with a major role in the toxicity, notably via its effects on inflammation. Both the particle count and the PAHs compositional data were assembled to be interpreted by Principal Components Analysis. This multivariate analysis grouped the data according mainly to the naphthalene amount, as well as the volume concentration of the particles smaller than 0.5 μm, suggesting that the different exhaust emissions could be easily differentiated. With this new methodology, future research should aim at establishing a mechanism of formation during internal engine combustion processes in order to obtain a clearer picture of the inflammatory and carcinogenic mechanisms of PM in the lungs.
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Affiliation(s)
- M. Pacenti
- Occupational Medicine Division, Department of Public Health, University of Florence
| | | | - S. Dugheri
- Occupational Medicine Division, Department of Public Health, University of Florence
| | - A. Zoppi
- Chemistry Department, University of Florence
| | - I. Borsi
- Department of Mathematics U. Dini, University of Florence
| | - A. Speranza
- Innovazione Industriale Tramite Trasferimento Tecnologico, Florence
| | - P. Boccalon
- Occupational Medicine Division, Department of Public Health, University of Florence
| | - G. Arcangeli
- Occupational Medicine Division, Department of Public Health, University of Florence
| | - A. Antoniucci
- Occupational Medicine Division, Department of Biomedical Science, University of Chieti-Pescara, Chieti, Italy
| | | | - V. Cupelli
- Occupational Medicine Division, Department of Public Health, University of Florence
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4
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Reyes-Garcés N, Gionfriddo E, Gómez-Ríos GA, Alam MN, Boyacı E, Bojko B, Singh V, Grandy J, Pawliszyn J. Advances in Solid Phase Microextraction and Perspective on Future Directions. Anal Chem 2017; 90:302-360. [DOI: 10.1021/acs.analchem.7b04502] [Citation(s) in RCA: 402] [Impact Index Per Article: 57.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
| | | | | | - Md. Nazmul Alam
- Department of Chemistry, University of Waterloo, Ontario, Canada N2L 3G1
| | - Ezel Boyacı
- Department of Chemistry, Middle East Technical University, Ankara 06800, Turkey
| | - Barbara Bojko
- Department of Pharmacodynamics and Molecular Pharmacology, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-067 Bydgoszcz, Poland
| | - Varoon Singh
- Department of Chemistry, University of Waterloo, Ontario, Canada N2L 3G1
| | - Jonathan Grandy
- Department of Chemistry, University of Waterloo, Ontario, Canada N2L 3G1
| | - Janusz Pawliszyn
- Department of Chemistry, University of Waterloo, Ontario, Canada N2L 3G1
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5
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Passive Sampling and Analysis of Naphthalene in Internal Combustion Engine Exhaust with Retracted SPME Device and GC-MS. ATMOSPHERE 2017. [DOI: 10.3390/atmos8070130] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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6
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Sun L, Zhang M, Natarajan V, Yu X, Zhang X, Zhan J. Au@Ag core–shell nanoparticles with a hidden internal reference promoted quantitative solid phase microextraction-surface enhanced Raman spectroscopy detection. RSC Adv 2017. [DOI: 10.1039/c7ra03164e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Structural representation of the SPME-SERS fiber with an internal reference and the SERS detection.
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Affiliation(s)
- Lei Sun
- Key Laboratory for Colloid & Interface Chemistry of Education Ministry
- Department of Chemistry
- Shandong University
- Jinan
- P. R. China
| | - Min Zhang
- Key Laboratory for Colloid & Interface Chemistry of Education Ministry
- Department of Chemistry
- Shandong University
- Jinan
- P. R. China
| | - Vinothkumar Natarajan
- Key Laboratory for Colloid & Interface Chemistry of Education Ministry
- Department of Chemistry
- Shandong University
- Jinan
- P. R. China
| | - Xiaofei Yu
- Key Laboratory for Colloid & Interface Chemistry of Education Ministry
- Department of Chemistry
- Shandong University
- Jinan
- P. R. China
| | - Xiaoli Zhang
- Key Laboratory for Colloid & Interface Chemistry of Education Ministry
- Department of Chemistry
- Shandong University
- Jinan
- P. R. China
| | - Jinhua Zhan
- Key Laboratory for Colloid & Interface Chemistry of Education Ministry
- Department of Chemistry
- Shandong University
- Jinan
- P. R. China
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Abstract
Microbubble fabrication (by use of a fine emulsion) provides a means of increasing the surface-area-to-volume (SAV) ratio of polymer materials, which is particularly useful for separations applications. Porous polydimethylsiloxane (PDMS) beads can be produced by heat-curing such an emulsion, allowing the interface between the aqueous and aliphatic phases to mold the morphology of the polymer. In the procedures described here, both polymer and crosslinker (triethoxysilane) are sonicated together in a cold-bath sonicator. Following a period of cross-linking, emulsions are added dropwise to a hot surfactant solution, allowing the aqueous phase of the emulsion to separate, and forming porous polymer beads. We demonstrate that this method can be tuned, and the SAV ratio optimized, by adjusting the electrolyte content of the aqueous phase in the emulsion. Beads produced in this way are imaged with scanning electron microscopy, and representative SAV ratios are determined using Brunauer-Emmett-Teller (BET) analysis. Considerable variability with the electrolyte identity is observed, but the general trend is consistent: there is a maximum in SAV obtained at a specific concentration, after which porosity decreases markedly.
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Affiliation(s)
| | - Matthew J Nee
- Department of Chemistry, Western Kentucky University;
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8
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Goienaga N, Sarmiento A, Olivares M, Carrero JA, Fernández LA, Madariaga JM. Emerging Application of a Structural and Chemical Analyzer for the Complete Characterization of Metal-Rich Particulate Matter. Anal Chem 2013; 85:7173-81. [DOI: 10.1021/ac400878y] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Naiara Goienaga
- Department of Analytical Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, E-48080,
Bilbao, Basque Country, Spain
| | - Alfredo Sarmiento
- Department of Analytical Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, E-48080,
Bilbao, Basque Country, Spain
| | - Maitane Olivares
- Department of Analytical Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, E-48080,
Bilbao, Basque Country, Spain
| | - Jose Antonio Carrero
- Department of Analytical Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, E-48080,
Bilbao, Basque Country, Spain
| | - Luis A. Fernández
- Department of Analytical Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, E-48080,
Bilbao, Basque Country, Spain
| | - Juan M. Madariaga
- Department of Analytical Chemistry, University of the Basque Country (UPV/EHU), P.O. Box 644, E-48080,
Bilbao, Basque Country, Spain
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9
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Zhao Q, Wajert JC, Anderson JL. Polymeric Ionic Liquids as CO2 Selective Sorbent Coatings for Solid-Phase Microextraction. Anal Chem 2009; 82:707-13. [PMID: 20038114 DOI: 10.1021/ac902438k] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Qichao Zhao
- Department of Chemistry, The University of Toledo, 2801 West Bancroft Street, MS 602, Toledo, Ohio 43606
| | - Jonathan C. Wajert
- Department of Chemistry, The University of Toledo, 2801 West Bancroft Street, MS 602, Toledo, Ohio 43606
| | - Jared L. Anderson
- Department of Chemistry, The University of Toledo, 2801 West Bancroft Street, MS 602, Toledo, Ohio 43606
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10
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Forbes PBC, Rohwer ER. Investigations into a novel method for atmospheric polycyclic aromatic hydrocarbon monitoring. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2009; 157:2529-2535. [PMID: 19345458 DOI: 10.1016/j.envpol.2009.03.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2008] [Accepted: 03/04/2009] [Indexed: 05/27/2023]
Abstract
A novel analytical method for atmospheric polycyclic aromatic hydrocarbons (PAHs) was developed based on laser induced fluorescence (LIF) of samples on quartz multi-channel polydimethylsiloxane traps. A tunable dye laser with a frequency doubling crystal provided the excitation radiation, and a double monochromator with a photomultiplier tube detected emitted fluorescence. The method allowed for the rapid (<5 min), cost effective analysis of samples. Those yielding interesting results could be further analysed by direct thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS, with limits of detection of approximately 0.3 ng m(-3)), as photodegradation was minimal (<10% over 5 min irradiation). Small amounts of naphthalene photodegradation products identified by TD-GC-MS after >15 min irradiation, included phenol, benzyl alcohol and phthalic anhydride. Without any signal optimization, a LIF detection limit of approximately 1 microg m(-3) was established for naphthalene using a diffusion tube (diffusion rate of 2 ng s(-1)) and 292 nm excitation.
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Affiliation(s)
- Patricia B C Forbes
- Natural Resources and the Environment, Council for Scientific and Industrial Research, PO Box 395, Pretoria 0001, South Africa.
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11
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Liou SW, Chen CY, Yang TT, Lin JM. Determination of particulate-bound formaldehyde from burning incense by solid phase microextraction. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2008; 80:324-328. [PMID: 18344073 DOI: 10.1007/s00128-008-9381-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Accepted: 02/25/2008] [Indexed: 05/26/2023]
Abstract
This work studied the feasibility of using a solid phase microextraction (SPME) fiber for sampling and analysis of gaseous formaldehyde as well as particulate-bound formaldehyde from burning Chinese incense. The SPME fiber with PDMS/DVB coating were partially coated with o-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine hydrochloride (PFBHA), and used for sampling formaldehyde. The sampling rate for formaldehyde and its dependence on temperature, relative humidity and sampling time were observed. The same PFBHA treated fibers were, in parallel, exposed to incense burning smoke with pre-filtration and without pre- filtration for 0.5-1 min. The NIOSH method 2541 using an XAD-2 tube at a flow rate of 0.1 Lpm was also applied for sampling simultaneously. The results demonstrate that commercially available PDMS/DVB fibers partially coated with PFBHA are capable of sampling the gas phase of formaldehyde as well as particulate-bound formaldehyde. The determined level of formaldehyde was close to the result obtained by the NIOSH method 2541. However, a reduction of the fiber's formaldehyde loading capacity in the aerosol sampling in comparison with gas sampling was noticed. This indicates that the particulate characteristics, and their bound chemicals other than formaldehyde may influence the maximum loading capacity of formaldehyde, and some characteristic particulates in high concentrations may even deteriorate the fiber coating.
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Affiliation(s)
- S W Liou
- Institute of Environmental Health, National Taiwan University, Taipei, 10055, Taiwan, Republic of China
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12
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Petry R, Mastalerz R, Zahn S, Mayerhöfer TG, Völksch G, Viereck-Götte L, Kreher-Hartmann B, Holz L, Lankers M, Popp J. Asbestos Mineral Analysis by UV Raman and Energy-Dispersive X-ray Spectroscopy. Chemphyschem 2006; 7:414-20. [PMID: 16389599 DOI: 10.1002/cphc.200500303] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The applicability of a UV micro-Raman setup was assessed for the rapid identification of fibrous asbestos minerals using 257 and 244 nm laser light for excitation. Raman spectra were obtained from six asbestos reference standards belonging to two basic structural groups: the serpentines (chrysotile) and the amphiboles (crocidolite, tremolite, amosite, anthophyllite, and actinolite). The UV Raman spectra reported here for the first time are free from fluorescence, which is especially helpful in assessing the hydroxyl-stretching vibrations. The spectra exhibit sharp bands characteristic of each asbestos species, which can be used for the unambiguous identification of known and unknown asbestos fibres. Evident changes of the relative band intensities sensitively reflect the chemical substitutions that typically occur in asbestos minerals. The elemental composition of the asbestos reference samples was analysed by using a scanning electron microscope equipped with an energy-dispersive X-ray (EDX) spectrometer. The discussion of the experimental results in terms of EDX analysis sheds new light on the structural and vibrational consequences of cation distribution in asbestos minerals.
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Affiliation(s)
- Renate Petry
- Institut für Physikalische Chemie, Universität Jena, Helmholtzweg 4, 07743 Jena (Germany)
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13
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De Jesús MA, Giesfeldt KS, Sepaniak MJ. Factors affecting the sorption of model environmental pollutants onto silver polydimethylsiloxane nanocomposite Raman substrates. APPLIED SPECTROSCOPY 2004; 58:1157-1164. [PMID: 15527515 DOI: 10.1366/0003702042336064] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The presence of aromatic compounds in water is an important topic in environmental sciences. Silver-polydimethylsiloxane nanocomposites (Ag-PDMS) have recently been demonstrated as promising substrates for the detection of model environmental pollutants via surface-enhanced Raman spectroscopy (SERS). This work discusses how different variables such as pH and matrix composition can affect the sorption and SERS activity of these chemicals. The results show that the conjugate base of weak acids can interact more efficiently with the substrate, leading to an increased signal at higher pH, while amino-aromatic compounds interact more efficiently at a lower pH. The sorption of these chemicals is an essential step in the process and has been attributed to the absorption of the analyte into the PDMS followed by its adsorption to the metallic surface. In addition, the presence of moderate concentrations (1 x 10(-4) M) of a supporting electrolyte such as nitrate or fluoride can improve the sorption of 4-hydroxybenzoic acid to the Ag-PDMS nanoparticles. Other ions such as phosphate and chloride cause rapid oxidation of the substrates even at concentrations as low as 1 x 10(-5) M. The effect of these variables in the analysis of real samples is presented. The potential use of liquid chromatography for isolating the model pollutants from detrimental matrix components in nat- ural waters is also shown.
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Affiliation(s)
- M A De Jesús
- University of Tennessee-Knoxville, Department of Chemistry, 552 Buehler Hall, Knoxville, Tennessee 37996-1600, USA
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Utsunomiya S, Jensen KA, Keeler GJ, Ewing RC. Direct identification of trace metals in fine and ultrafine particles in the Detroit urban atmosphere. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2004; 38:2289-97. [PMID: 15116832 DOI: 10.1021/es035010p] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Exposure to airborne particulates containing low concentrations of heavy metals, such as Pb, As, and Se, may have serious health effects. However, little is known about the speciation and particle size of these airborne metals. Fine- and ultrafine particles with heavy metals in aerosol samples from the Detroit urban area, Michigan, were examined in detail to investigate metal concentrations and speciation. The characterization of individual particles was completed using high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) combined with conventional high-resolution TEM techniques. The trace elements, Pb, As, La, Ce, Sr, Zn, Cr, Se, Sn, Y, Zr, Au, and Ag, were detected, and the elemental distributions were mapped in situ atthe nanoscale. The crystal structures of the particles containing Pb, Sr, Zn, and Au were determined from their electron diffraction patterns. Based on the characterization of the representative trace element particles, the potential health effects are discussed. Most of the trace element particles detected in this study were within a range of 0.01-1.0 microm in size, which has the longest atmospheric residence time (approximately 100 days). Increased chemical reactivity owing to the size of nanoparticles may be expected for most of the trace metal particles observed.
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Affiliation(s)
- Satoshi Utsunomiya
- Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109-1063, USA
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15
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De Jesús MA, Giesfeldt KS, Sepaniak MJ. Use of a sample translation technique to minimize adverse effects of laser irradiation in surface-enhanced Raman spectrometry. APPLIED SPECTROSCOPY 2003; 57:428-38. [PMID: 14658640 DOI: 10.1366/00037020360625970] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Surface-enhanced Raman spectroscopy (SERS) has proven to be a very powerful tool in the analysis of a wide range of compounds. However, continuous irradiation of the laser beam over the SERS substrate can promote the gross decomposition of the sample analytes and significantly broaden and diminish the intensities of observed spectral bands. In addition, the incident radiation can promote thermal or photolytic fragmentation of analytes, thereby altering the observable bands and possibly leading to a misinterpretation of analytical data. Finally, chemical or morphological changes in the SERS substrate are possible. This work presents the use of a sample translation technique (STT) as a means to minimize these adverse effects. By spinning the sample rapidly, the effective residence time of analytes and substrate within the irradiated zone is dramatically decreased without reduction of spectral acquisition time or the density of analyte in the zone. The technique is studied by acquiring SERS spectra of Naproxen USP, riboflavin, folic acid, Rhodamine 6G, and 4-aminothiophenol using silver islands on glass and silver-poly(dimethylsiloxane) composite substrates under various spinning and stationary conditions. In all cases, spectra show improvements upon spinning at laser powers as low as 4.2 (+/- 0.1) mW. Specific differences in the appearance of the spectra and the potential use of STT for improved SERS qualitative and quantitative determinations are presented.
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Affiliation(s)
- M A De Jesús
- University of Tennessee-Knoxville, Department of Chemistry, 552 Buehler Hall, Knoxville, Tennessee 37996-1600, USA
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16
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Pawliszyn J. Chapter 13 Solid phase microextraction. SAMPLING AND SAMPLE PREPARATION FOR FIELD AND LABORATORY 2002. [DOI: 10.1016/s0166-526x(02)80050-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Chapter 1 Sampling and sample preparation for indoor air analysis. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0166-526x(02)80038-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Santato C, Odziemkowski M, Ulmann M, Augustynski J. Crystallographically oriented mesoporous WO3 films: synthesis, characterization, and applications. J Am Chem Soc 2001; 123:10639-49. [PMID: 11673995 DOI: 10.1021/ja011315x] [Citation(s) in RCA: 398] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mesoporous semiconducting films consisting of preferentially orientated monoclinic-phase nanocrystals of tungsten trioxide have been prepared using a novel version of the sol-gel method. Transformations undergone by a colloidal solution of tungstic acid, stabilized by an organic additive such as poly(ethylene glycol) (PEG) 300, as a function of the annealing temperature have been followed by means of a confocal Raman microscope. The shape and size of WO3 nanoparticles, the porosity, and the properties of the films depend critically on preparation parameters, such as the tungstic acid/PEG ratio, the PEG chain length, and the annealing conditions. Well-crystallized WO3 films combine excellent photoresponse to the blue region of the solar spectrum, up to 500 nm, with good transparency at wavelengths larger than 550 nm. Particular applications of these nanocrystalline WO3 films include photoelectrochemical and electrochromic devices.
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Affiliation(s)
- C Santato
- Department of Chemistry, University of Geneva, CH-1211 Geneva 4, Switzerland
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