scholarly journals Quantifying organic matter and functional groups in particulate matter filter samples from the southeastern United States – Part 1: Methods

2019 ◽  
Vol 12 (10) ◽  
pp. 5391-5415 ◽  
Author(s):  
Alexandra J. Boris ◽  
Satoshi Takahama ◽  
Andrew T. Weakley ◽  
Bruno M. Debus ◽  
Carley D. Fredrickson ◽  
...  
Keyword(s):  
Organic Matter ◽  
Functional Groups ◽  
Atmospheric Chemistry ◽  
Functional Group ◽  
Aerosol Composition ◽  
Ir Spectrometry ◽  
Southeastern Us ◽  
Inorganic Species ◽  
Calibration Models ◽  
Ft Ir

Abstract. Comprehensive techniques to describe the organic composition of atmospheric aerosol are needed to elucidate pollution sources, gain insights into atmospheric chemistry, and evaluate changes in air quality. Fourier transform infrared absorption (FT-IR) spectrometry can be used to characterize atmospheric organic matter (OM) and its composition via functional groups of aerosol filter samples in air monitoring networks and research campaigns. We have built FT-IR spectrometry functional group calibration models that improve upon previous work, as demonstrated by the comparison of current model results with those of previous models and other OM analysis methods. Laboratory standards that simulated the breadth of the absorbing functional groups in atmospheric OM were made: particles of relevant chemicals were first generated, collected, and analyzed. Challenges of collecting atmospherically relevant particles and spectra were addressed by including interferences of particle water and other inorganic aerosol constituents and exploring the spectral effects of intermolecular interactions. Calibration models of functional groups were then constructed using partial least-squares (PLS) regression and the collected laboratory standard data. These models were used to quantify concentrations of five organic functional groups and OM in 8 years of ambient aerosol samples from the southeastern aerosol research and characterization (SEARCH) network. The results agreed with values estimated using other methods, including thermal optical reflectance (TOR) organic carbon (OC; R2=0.74) and OM calculated as a difference between total aerosol mass and inorganic species concentrations (R2=0.82). Comparisons with previous calibration models of the same type demonstrate that this new, more complete suite of chemicals has improved our ability to estimate oxygenated functional group and overall OM concentrations. Calculated characteristic and elemental ratios including OM∕OC, O∕C, and H∕C agree with those from previous work in the southeastern US, substantiating the aerosol composition described by FT-IR calibration. The median OM∕OC ratio over all sites and years was 2.1±0.2. Further results discussing temporal and spatial trends of functional group composition within the SEARCH network will be published in a forthcoming article.

scholarly journals Quantifying organic matter and functional groups in particulate matter filter samples from the southeastern United States, part I: Methods

2019 ◽  
Author(s):  
Alexandra J. Boris ◽  
Satoshi Takahama ◽  
Andrew T. Weakley ◽  
Bruno M. Debus ◽  
Carley D. Fredrickson ◽  
...  
Keyword(s):  
Organic Matter ◽  
Functional Groups ◽  
Atmospheric Chemistry ◽  
Functional Group ◽  
Aerosol Composition ◽  
Ir Spectrometry ◽  
Southeastern Us ◽  
Inorganic Species ◽  
Calibration Models ◽  
Ft Ir

Abstract. Comprehensive techniques to describe the organic composition of atmospheric aerosol are needed to elucidate pollution sources, gain insights into atmospheric chemistry and evaluate changes in air quality. Fourier Transform Infrared absorption (FT-IR) spectrometry can be used to characterize atmospheric organic matter (OM) and its composition via functional groups on aerosol filter samples in air monitoring networks and research campaigns. We have built FT-IR spectrometry functional group calibration models that improve upon previous work. Laboratory standards that simulated the breadth of the absorbing functional groups in atmospheric OM were made: particles of relevant chemicals were first generated, collected, and analyzed. Challenges of collecting atmospherically relevant particles and spectra were addressed by including interferences of particle water and other inorganic aerosol constituents and exploring the spectral effects of inter-molecular interactions. Calibration models of functional groups were then constructed using partial least squares (PLS) regression and the collected laboratory standard data. These models were used to quantify concentrations of five organic functional groups and OM in eight years of ambient aerosol samples from the southeastern aerosol research and characterization (SEARCH) network. The results agreed with values estimated using other methods, including thermal optical reflectance (TOR) organic carbon (OC; R2 = 0.74) and OM calculated as a difference between total aerosol mass and inorganic species concentrations (R2 = 0.82). Comparisons with previous calibration models of the same type demonstrate that this new, more complete suite of chemicals has improved our ability to estimate oxygenated functional group and overall OM concentrations. Calculated characteristic and elemental ratios including OM/OC, O/C and H/C agree with those from previous work in the southeastern US, substantiating the aerosol composition described by FT-IR calibration. The median OM/OC ratio over all sites and years was 2.1 ± 0.2. Further results discussing temporal and spatial trends of functional group composition within the SEARCH network will be published in a forthcoming article.

scholarly journals Quantifying organic matter and functional groups in particulate matter filter samples from the southeastern United States – Part 2: Spatiotemporal trends

2021 ◽  
Vol 14 (6) ◽  
pp. 4355-4374
Author(s):  
Alexandra J. Boris ◽  
Satoshi Takahama ◽  
Andrew T. Weakley ◽  
Bruno M. Debus ◽  
Stephanie L. Shaw ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carboxylic Acid ◽  
Functional Groups ◽  
Functional Group ◽  
Ir Spectrometry ◽  
Spatiotemporal Trends ◽  
Southeastern Us ◽  
Time Period ◽  
Routine Monitoring ◽  
Ft Ir

Abstract. Organic species within atmospheric particles vary widely in molecular structure. The variety of molecules that comprise the aerosol make it rich in information about its sources and chemical life cycle but also make particulate organic matter (OM) difficult to characterize and quantify. In Part 1 of this pair of papers, we described a direct method for measuring the composition and concentrations of OM in aerosol samples that is compatible with routine monitoring of air quality. This method uses Fourier transform infrared (FT-IR) spectrometry of filter-based aerosol samples to quantify bonds, or functional groups, that represent the majority of organic composition. Summation of these functional groups gives OM. In this paper, functional group and OM concentrations are directly measured in 8 years of aerosol samples collected at two rural and two urban sites in the Southeastern Aerosol Research and Characterization (SEARCH) network. FT-IR spectrometry with a multivariate calibration is used to quantify the concentrations of aliphatic C−H (aCH), carboxylic acid (COOH), oxalate (oxOCO; representing carboxylates), non-acid and non-oxalate carbonyl (naCO), and alcohol O−H (aCOH) in approximately 3500 filter samples collected every third day from 2009 through 2016. In addition, measurements are made on samples from all days in 2016. To the best of our knowledge, this is the longest time period over which this type of analysis has been applied, and this work also demonstrates the application of a more chemically complete and less destructive method than in prior work using alternate techniques. A decline in the total OM is observed from 2011 to 2016 due to a decrease in the more oxygenated functional groups (carboxylic acid and oxalate) and is attributed to anthropogenic SO2 and/or volatile organic compound (VOC) emissions reductions. The trend in OM composition is consistent with those observed using more time- and labor-intensive analytical techniques. Concurrently, the fractional contributions of aCOH and naCO to OM increased, which might be linked to monoterpene-derived secondary OM, with plausible influences from decreasing NOx and/or increasing O3 concentrations. In addition, this work demonstrates that OM to organic carbon (OM/OC) ratios in the southeastern US (SE US) did not appreciably change over the study time period as a result of these competing functional group contributions to OM. Monthly observations support the sources suggested by these overall trends, including evidence of strong biogenic and photo-oxidation influences. Daily samples from 2016 further elucidate the consistent impact of meteorology and biomass burning events on shorter-term OM variability, including prescribed burning in the winter or spring and wildfires in the autumn, although these sources did not appear to be strong contributors to long-term OM or composition trends in the SE US. These shorter-term and spatial observations reinforce the results of the broader dataset and serve to evaluate the applicability of FT-IR spectrometry measurement to trends analysis on various timescales relevant to routine monitoring of aerosol composition.

scholarly journals Quantifying organic matter and functional groups in particulate matter filter samples from the southeastern United States – Part 2: Spatiotemporal Trends

2021 ◽  
Author(s):  
Alexandra J. Boris ◽  
Satoshi Takahama ◽  
Andrew T. Weakley ◽  
Bruno M. Debus ◽  
Stephanie L. Shaw ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carboxylic Acid ◽  
Functional Groups ◽  
Prescribed Burning ◽  
Functional Group ◽  
Aerosol Composition ◽  
Ir Spectrometry ◽  
Spatiotemporal Trends ◽  
Routine Monitoring ◽  
Ft Ir

Abstract. Organic species within atmospheric particles vary widely in molecular structure. The variety of molecules that comprise the aerosol make it rich in information about its sources and chemical lifecycle but also make particulate organic matter (OM) difficult to characterize and quantify. In Part 1 of this pair of papers, we described a direct method for measuring the composition and concentration of OM in aerosol samples that is compatible with routine monitoring of air quality. This method uses Fourier Transform Infrared (FT-IR) spectrometry of filter-based aerosol samples to quantify bonds, or functional groups, that represent the majority of organic composition; summation of these functional groups gives OM. In this paper, functional group composition and OM concentrations are directly measured in eight years of aerosol samples collected at two rural and two urban sites in the Southeastern Aerosol Research and Characterization (SEARCH) network. FT-IR spectrometry with a multivariate calibration is used to quantify the concentrations of aliphatic C-H (aCH), carboxylic acid (COOH), oxalate (oxOCO; representing carboxylates), non-acid and non-oxalate carbonyl (naCO), and alcohol O-H (aCOH) in approximately 3500 filter samples collected every third day from 2009 through 2016. In addition, measurements are made on samples from all days in 2016. A decline in the total OM is observed from 2011 to 2016 that is caused by decreases in the more oxygenated functional groups (carboxylic acid and oxalate) and is attributed to anthropogenic SO2 and/or volatile organic compound (VOC) emissions reductions. The trend in OM composition is consistent with those observed using more time- and labor-intensive analytical techniques. Concurrently, the fractional contributions of aCOH and naCO to OM increased, which might be linked to monoterpene-derived secondary OM, with possible influences from decreasing NOx and/or increasing O3 concentrations. In addition, this work demonstrates that OM to organic carbon (OM / OC) ratios in the Southeast U.S. (SE U.S.) did not appreciably change over the study time period, as a result of these competing functional group contributions to OM. Monthly observations support the sources suggested by these overall trends, including strong biogenic and photo-oxidation influences, while daily samples from 2016 further elucidate the consistent impact of meteorology and biomass burning events on shorter term OM variability, including prescribed burning in the winter/spring and wildfires in the autumn. These shorter-term and spatial observations thus reinforce the results of the broader dataset and serve to evaluate the applicability of FT-IR spectrometry measurement to trends analysis on various timescales relevant to routine monitoring of aerosol composition.

scholarly journals Technical Note: Relating functional group measurements to carbon types for improved model-measurement comparisons of organic aerosol composition

2016 ◽  
Author(s):  
Satoshi Takahama ◽  
Giulia Ruggeri
Keyword(s):  
Organic Carbon ◽  
Functional Group ◽  
Organic Aerosol ◽  
Chem Phys ◽  
Technical Note ◽  
Molecular Structures ◽  
Organic Carbon Content ◽  
Aerosol Composition ◽  
Ft Ir ◽  
Model Measurement

Abstract. Functional group (FG) analysis provides a means by which functionalization in organic aerosol can be attributed to the abundances of its underlying molecular structures. However, performing this attribution requires additional, unobserved details about the molecular mixture to provide constraints in the estimation process. To address this issue, we present an approach for conceptualizing FG measurements of organic aerosol in terms of its functionalized carbon atoms. This reformulation facilitates estimation of mass recovery and biases in popular carbon-centric metrics that describe the extent of functionalization (such as oxygen to carbon ratio, organic mass to organic carbon mass ratio, and mean carbon oxidation state) for any given set of molecules and FGs analyzed. Furthermore, this approach allows development of parameterizations to more precisely estimate the organic carbon content from measured FG abundance. We use simulated photooxidation products of α-pinene secondary organic aerosol previously reported by Ruggeri et al. (Atmos. Chem. Phys., 16, 4401–4422, 2016) and FG measurements by Fourier Transform Infrared (FT-IR) spectroscopy in chamber experiments by Sax et al. (Aerosol Sci. Tech., 39, 822–830, 2005) to infer the relationships among molecular composition, FG composition, and metrics of organic aerosol functionalization. We find that for this simulated system, ~ 80 % of the carbon atoms should be detected by FGs for which calibration models are commonly developed, and ~ 7 % of the carbon atoms are undetectable by FT-IR analysis because they are not associated with vibrational modes in the infrared. Estimated biases due to undetected carbon fraction for these simulations are used to make adjustments in these carbon-centric metrics such that model-measurement differences are framed in terms of unmeasured heteroatoms (e.g., in hydroperoxide and nitrate groups for the case studied in this demonstration). The formality of this method provides framework for extending FG analysis to not only model-measurement but also instrument intercomparisons in other chemical systems.

scholarly journals Analysis of functional groups in atmospheric aerosols by infrared spectroscopy: sparse methods for statistical selection of relevant absorption bands

2016 ◽  
Vol 9 (7) ◽  
pp. 3429-3454 ◽  
Author(s):  
Satoshi Takahama ◽  
Giulia Ruggeri ◽  
Ann M. Dillner
Keyword(s):  
Infrared Spectra ◽  
Atmospheric Aerosols ◽  
Quantitative Prediction ◽  
Calibration Model ◽  
Vibrational Modes ◽  
Aerosol Composition ◽  
Absorption Bands ◽  
Calibration Models ◽  
Ft Ir ◽  
Selection Of

Abstract. Various vibrational modes present in molecular mixtures of laboratory and atmospheric aerosols give rise to complex Fourier transform infrared (FT-IR) absorption spectra. Such spectra can be chemically informative, but they often require sophisticated algorithms for quantitative characterization of aerosol composition. Naïve statistical calibration models developed for quantification employ the full suite of wavenumbers available from a set of spectra, leading to loss of mechanistic interpretation between chemical composition and the resulting changes in absorption patterns that underpin their predictive capability. Using sparse representations of the same set of spectra, alternative calibration models can be built in which only a select group of absorption bands are used to make quantitative prediction of various aerosol properties. Such models are desirable as they allow us to relate predicted properties to their underlying molecular structure. In this work, we present an evaluation of four algorithms for achieving sparsity in FT-IR spectroscopy calibration models. Sparse calibration models exclude unnecessary wavenumbers from infrared spectra during the model building process, permitting identification and evaluation of the most relevant vibrational modes of molecules in complex aerosol mixtures required to make quantitative predictions of various measures of aerosol composition. We study two types of models: one which predicts alcohol COH, carboxylic COH, alkane CH, and carbonyl CO functional group (FG) abundances in ambient samples based on laboratory calibration standards and another which predicts thermal optical reflectance (TOR) organic carbon (OC) and elemental carbon (EC) mass in new ambient samples by direct calibration of infrared spectra to a set of ambient samples reserved for calibration. We describe the development and selection of each calibration model and evaluate the effect of sparsity on prediction performance. Finally, we ascribe interpretation to absorption bands used in quantitative prediction of FGs and TOR OC and EC concentrations.

scholarly journals PHYTOCHEMICAL STUDIES AND GC-MS ANALYSIS OF SPERMADICTYON SUAVEOLENS ROXB

2017 ◽  
Vol 9 (3) ◽  
pp. 143 ◽  
Author(s):  
Ruthiran Papitha ◽  
Lokesh Ravi ◽  
Chinnadurai Immanuel Selvaraj
Keyword(s):  
Functional Groups ◽  
Mass Spectra ◽  
Ultra Violet ◽  
Chloroform Extract ◽  
Leaf Extracts ◽  
Ir Spectrometry ◽  
Ms Analysis ◽  
Ft Ir ◽  
Phytochemical Constituents ◽  
Phytochemical Studies

Objective: The present study was performed to identify the phytochemical constituents of leaves and flowers of a plant Spermadictyon suaveolens extracted with four different solvents.Methods: Dried and powdered samples were subjected to soxhlation based on the polarity of the solvents. The extracts were scanned using Ultra Violet-visible (UV-Vis) spectrophotometry with the wavelength ranging from 200–800 nm by comparing the absorption spectrum with the spectra of known compounds, Fourier Transform Infrared (FT-IR) spectrometry was used to find out the functional groups of the compounds and GC-MS system consisting of a Perkin Elmer Technologies Model Clarus 680 GC equipped with Clarus 600 (EI) was used to identify the metabolites by matching their recorded mass spectra with the standard mass spectra from National Institute of Standards and Technology (NIST05. LIB) libraries provided by the software of the GCMS system (TurboMass version 5.4.2).Results: The phytochemical tests indicated the presence of carbohydrates, alkaloids, flavonoids, phenols, tannins, saponins and terpenoids from the chloroform extract of leaves and flowers. UV-visible spectrophotometer results indicated a wavelength range between 230–660 nm for the flower and leaf extracts for major peaks. FT-IR analysis indicated major functional groups such as aromatic, primary, secondary and aliphatic amines, alkanes, carboxylic acids and amides. GC-MS analysis results revealed major bioactive compounds in the crude extracts.Conclusion: Presence of secondary metabolites has been identified from the phytochemical studies. Many phyto-compounds have been identified from the leaves and flowers of using GC-MS analysis. Hence, this medicinal plant may be used as a source for treating many diseases.

scholarly journals Biogenic oxidized organic functional groups in aerosol particles from a mountain forest site and their similarities to laboratory chamber products

2010 ◽  
Vol 10 (2) ◽  
pp. 4789-4822 ◽  
Author(s):  
R. E. Schwartz ◽  
L. M. Russell ◽  
S. J. Sjosted ◽  
A. Vlasenko ◽  
J. G. Slowik ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Functional Groups ◽  
Functional Group ◽  
Group Composition ◽  
Organic Aerosol ◽  
Anthropogenic Sources ◽  
Forest Site ◽  
Aerosol Composition ◽  
X Ray ◽  
Organic Functional Groups

Abstract. Submicron particles collected at Whistler, British Columbia, at 1020 masl during May and June 2008 on Teflon filters were analyzed by Fourier transform infrared (FTIR) and X-ray fluorescence (XRF) techniques for organic functional groups (OFG) and elemental composition. Organic mass (OM) ranged from less than 0.5 to 3.1μg m−3, with a project mean and standard deviation of 1.3±1.0 μg m−3 and 0.21±0.16 μg m−3 for OM and sulfate, respectively. On average, organic hydroxyl, alkane, and carboxylic acid groups represented 34%, 33%, and 23% of OM, respectively. Ketone, amine and organosulfate groups constituted 6%, 5%, and <1% of the average organic aerosol composition, respectively. Measurements of volatile organic compounds (VOC), including isoprene and monoterpenes from biogenic VOC (BVOC) emissions and their oxidation products (methyl-vinylketone/methacrolein, MVK/MACR), were made using co-located proton transfer reaction mass spectrometry (PTR-MS). We present chemically-specific evidence of OFG associated with BVOC emissions. Positive matrix factorization (PMF) analysis attributed 65% of the campaign OM to biogenic sources, based on the correlations of one factor to monoterpenes and MVK/MACR. The remaining fraction was attributed to anthropogenic sources based on a correlation to sulfate. The functional group composition of the biogenic factor (consisting of 32% alkane, 25% carboxylic acid, 2% organic hydroxyl, 16% ketone, and 6% amine groups) was similar to that of secondary organic aerosol (SOA) reported from the oxidation of BVOCs in laboratory chamber studies, providing evidence that the magnitude and chemical composition of biogenic SOA simulated in the laboratory is similar to that found in actual atmospheric conditions. The biogenic factor OM is also correlated to dust elements, indicating that dust may act as a non-acidic SOA sink. This role is supported by the organic functional group composition and morphology of single particles, which were analyzed by scanning transmission X-ray microscopy near edge X-ray absorption fine structure (STXM-NEXAFS).

scholarly journals Biogenic oxidized organic functional groups in aerosol particles from a mountain forest site and their similarities to laboratory chamber products

2010 ◽  
Vol 10 (11) ◽  
pp. 5075-5088 ◽  
Author(s):  
R. E. Schwartz ◽  
L. M. Russell ◽  
S. J. Sjostedt ◽  
A. Vlasenko ◽  
J. G. Slowik ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Functional Groups ◽  
Functional Group ◽  
Group Composition ◽  
Organic Aerosol ◽  
Anthropogenic Sources ◽  
Forest Site ◽  
Aerosol Composition ◽  
X Ray ◽  
Organic Functional Groups

Abstract. Submicron particles collected at Whistler, British Columbia, at 1020 m a.s.l. during May and June 2008 on Teflon filters were analyzed by Fourier transform infrared (FTIR) and X-ray fluorescence (XRF) techniques for organic functional groups (OFG) and elemental composition. Organic mass (OM) concentrations ranged from less than 0.5 to 3.1 μg m−3, with a project mean and standard deviation of 1.3±1.0 μg m−3 and 0.21±0.16 μg m−3 for OM and sulfate, respectively. On average, organic hydroxyl, alkane, and carboxylic acid groups represented 34%, 33%, and 23% of OM, respectively. Ketone, amine and organosulfate groups constituted 6%, 5%, and <1% of the average organic aerosol composition, respectively. Measurements of volatile organic compounds (VOC), including isoprene and monoterpenes from biogenic VOC (BVOC) emissions and their oxidation products (methyl-vinylketone / methacrolein, MVK/MACR), were made using co-located proton transfer reaction mass spectrometry (PTR-MS). We present chemically-specific evidence of OFG associated with BVOC emissions. Positive matrix factorization (PMF) analysis attributed 65% of the campaign OM to biogenic sources, based on the correlations of one factor to monoterpenes and MVK/MACR. The remaining fraction was attributed to anthropogenic sources based on a correlation to sulfate. The functional group composition of the biogenic factor (consisting of 32% alkane, 25% carboxylic acid, 21% organic hydroxyl, 16% ketone, and 6% amine groups) was similar to that of secondary organic aerosol (SOA) reported from the oxidation of BVOCs in laboratory chamber studies, providing evidence that the magnitude and chemical composition of biogenic SOA simulated in the laboratory is similar to that found in actual atmospheric conditions. The biogenic factor OM is also correlated to dust elements, indicating that dust may act as a non-acidic SOA sink. This role is supported by the organic functional group composition and morphology of single particles, which were analyzed by scanning transmission X-ray microscopy near edge X-ray absorption fine structure (STXM-NEXAFS).

scholarly journals A Multi-Method Approach for Quantification of Surface Coatings on Commercial Zinc Oxide Nanomaterials

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 678 ◽  
Author(s):  
Filip Kunc ◽  
Oltion Kodra ◽  
Andreas Brinkmann ◽  
Gregory P. Lopinski ◽  
Linda J. Johnston
Keyword(s):  
Solid State ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Solid State Nmr ◽  
Functional Group ◽  
Surface Groups ◽  
X Ray ◽  
Ft Ir ◽  
Multi Method Approach ◽  
Method Approach

Surface functionalization is a key factor for determining the performance of nanomaterials in a range of applications and their fate when released to the environment. Nevertheless, it is still relatively rare that surface groups or coatings are quantified using methods that have been carefully optimized and validated with a multi-method approach. We have quantified the surface groups on a set of commercial ZnO nanoparticles modified with three different reagents ((3-aminopropyl)-triethoxysilane, caprylsilane and stearic acid). This study used thermogravimetric analysis (TGA) with Fourier transform infrared spectroscopy (FT-IR) of evolved gases and quantitative solution 1H nuclear magnetic resonance (NMR) for quantification purposes with 13C-solid state NMR and X-ray photoelectron spectroscopy to confirm assignments. Unmodified materials from the same suppliers were examined to assess possible impurities and corrections. The results demonstrate that there are significant mass losses from the unmodified samples which are attributed to surface carbonates or residual materials from the synthetic procedure used. The surface modified materials show a characteristic loss of functional group between 300–600 °C as confirmed by analysis of FT-IR spectra and comparison to NMR data obtained after quantitative release/extraction of the functional group from the surface. The agreement between NMR and TGA estimates for surface loading is reasonably good for cases where the functional group accounts for a relatively large fraction of the sample mass (e.g., large groups or high loading). In other cases TGA does not have sufficient sensitivity for quantitative analysis, particularly when contaminants contribute to the TGA mass loss. X-ray photoelectron spectroscopy and solid state NMR for selected samples provide support for the assignment of both the functional groups and some impurities. The level of surface group loading varies significantly with supplier and even for different batches or sizes of nanoparticles from the same supplier. These results highlight the importance of developing reliable methods to detect and quantify surface functional groups and the importance of a multi-method approach.

scholarly journals RESPON KOMUNITAS BENTHIK INSEKTA EMPAT BULAN PASCA-KEBAKARAN HUTAN 2002 DI HULU KALI BOYONG GUNUNG MERAPI

2015 ◽  
Vol 4 (2) ◽  
Author(s):  
Tjut Sugandawaty Djohan
Keyword(s):  
Organic Matter ◽  
Functional Groups ◽  
Forest Fire ◽  
Food Chain ◽  
Benthic Community ◽  
Functional Group ◽  
Forest Health ◽  
Insect Community ◽  
Surber Sampler

The purpose of this research is to study the response of benthic insect community in the headwater of BoyongRiver, Mount Merapi, four months post-forest fire in 2002. Energy at the headwater ecosystem was based on thedetritus food-chain. The presence of benthic community indicated forest health. The forest fire caused energy whichentered into the river changed from allochtonous coarse particulat organic matter (CPOM) to fine particulatorganic matter (FPOM). This change would be responded by the functional group of benthic community. Datawere collected with Surber Sampler. The result showed that there were 12 genus constituent of benthic insectsconsisted of functional groups of collector gather, collector filter, predator, dan scrapper. The dominant functionalgroups were collector gather and collector filters, 2256 individual/m3 or 86.02% and the dominant genus of Baetisand Leutcra. Otherwise, scrapper was founded 111 individual/m3 or 4% and predator 256 individual/m3 or 10%.This condition showed that four months post-forest fire indicated dominant allochtonous in Boyong River wasCPOM and FPOM with size of 1 mm. The quality of nutrients in the water was low, otherwise, the sedimentnutrients was high. The dominance of functional group of collectors indicated that ecosystem of headwater forestin Boyong River had not been fully recovered.

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