Analysis of Pesticides and Their Degradation Products in Rainwater: A Probe into Their Atmospheric Degradation

2-Bromo-3,3,3-trifluoropropene (2-BTP) is applied in confined places as a potential Halon replacement. This work reports the atmospheric degradation products and the mechanism of 2-BTP, and results show BTP to be an environmentally acceptable compound.

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Evaluation of the daytime tropospheric loss of 2-methylbutanal

10.5194/acp-2021-758 ◽

2021 ◽

Author(s):

María Asensio ◽

María Antiñolo ◽

Sergio Blázquez ◽

José Albaladejo ◽

Elena Jiménez

Keyword(s):

Mass Spectrometry ◽

Gas Phase ◽

Degradation Products ◽

Rate Coefficients ◽

Oh Radicals ◽

Phase Reaction ◽

Gaseous Products ◽

Flight Mass Spectrometry ◽

Atmospheric Degradation ◽

The Impact

Abstract. Saturated aldehydes, e.g. 2-methylbutanal (2MB, CH3CH2CH(CH3)C(O)H), are emitted into the atmosphere by several biogenic sources. The first step in the daytime atmospheric degradation of 2MB involves gas-phase reactions initiated by hydroxyl (OH) radicals, chlorine (Cl) atoms and/or sunlight. In this work, we report the rate coefficients for the gas-phase reaction of 2MB with OH (kOH) and Cl (kCl) together with the photolysis rate coefficient (J) in the ultraviolet solar actinic region in Valencia (Spain) at different times of the day. The temperature dependence of kOH was described in the 263–353 K range by the following Arrhenius expression: kOH(T)=(8.88±0.41)×10-12 exp[(331±14)/T] cm3 molecule-1 s-1. At 298 K, the reported kOH and kCl are (2.68±0.07)×10-11 cm3 molecule-1 s-1 and (2.16±0.16)×10-11 cm3 molecule-1 s-1. Identification and quantification of the gaseous products of the Cl-reaction and those from the photodissociation of 2MB were carried out in a smog chamber by different techniques (Fourier transform infrared spectroscopy, proton transfer time-of-flight mass spectrometry, and gas chromatography coupled to mass spectrometry). The formation and size distribution of secondary organic aerosols formed in the Cl-reaction was monitored by a fast mobility particle sizer spectrometer. A discussion on the relative importance of the first step in the daytime atmospheric degradation of 2MB is presented together with the impact of the degradation products in marine atmospheres.

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A zero-dimensional view of atmospheric degradation of levoglucosan (LEVCHEM_v1) using numerical chamber simulations

Geoscientific Model Development ◽

10.5194/gmd-14-907-2021 ◽

2021 ◽

Vol 14 (2) ◽

pp. 907-921

Author(s):

Loredana G. Suciu ◽

Robert J. Griffin ◽

Caroline A. Masiello

Keyword(s):

Gas Phase ◽

Degradation Products ◽

Heterogeneous Reaction ◽

Reaction Rate Constant ◽

Chemical Degradation ◽

Secondary Products ◽

Modeling Framework ◽

Mixing Ratios ◽

Fire Plumes ◽

Atmospheric Degradation

Abstract. Here, we developed a zero-dimensional (0-D) modeling framework (LEVCHEM_v1) to provide insights into the atmospheric degradation of a key tracer emitted during biomass burning – levoglucosan (LEV), while additionally exploring its effects on the dynamics of secondary organic aerosols (SOA) and other gases. For this, we updated existing chemical mechanisms (homogeneous gas-phase chemistry and heterogeneous chemistry) in the BOXMOXv1.7 model to include the chemical degradation of LEV and its intermediary degradation products in both phases (gas and aerosol). In addition, we added a gas-particle partitioning mechanism to the model to account for the effect of evaporation and condensation on the phase-specific concentrations of LEV and its degradation products. Comparison of simulation results with measurements from various chamber experiments (spanning summer and winter conditions) show that the degradation timescale of LEV varied by phase, with gas-phase degradation occurring over ∼1.5–5 d and aerosol-phase degradation occurring over ∼8–36 h. These relatively short timescales suggest that most of the initial LEV concentration can be lost chemically or deposited locally before being transported regionally. We varied the heterogeneous reaction rate constant in a sensitivity analysis (for summer conditions only) and found that longer degradation timescales of LEV are possible, particularly in the aerosol phase (7 d), implying that some LEV may be transported regionally. The multiphase chemical degradation of LEV has effects on SOA and other gases. Several first- or second-generation products resulted from its degradation; most of the products include one or two carbonyl groups, one product contains a nitrate group, and a few products show the cleavage of C−C bonds. The relative importance of the products varies depending on the phase and the timing of the maximum concentration achieved during the simulation. Our estimated secondary organic aerosol SOA yields (4 %–32 %) reveal that conversion of LEV to secondary products is significant and occurs rapidly in the studied scenarios. LEV degradation affected other gases by increasing the concentrations of radicals and decreasing those of reactive nitrogen species. Decreases of the mixing ratios of nitrogen oxides appear to drive a more rapid increase in ozone compared with changes in volatile organic compounds levels. An important next step to confirm longer degradation timescales will be to extend the evaluation of the modeled LEV degradation beyond 3–6 h by using more extensive data from chambers and, possibly, from fire plumes. The mechanism developed here can be used in chemical transport models applied to fire plumes to trace LEV and its degradation products from source to deposition, to assess their atmospheric implications and to answer questions relevant to fire tracing, carbon and nitrogen cycling, and climate.

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Determination of atmospheric degradation products of toluene by tandem mass spectrometry

Analytical Chemistry ◽

10.1021/ac00272a029 ◽

1984 ◽

Vol 56 (8) ◽

pp. 1329-1335 ◽

Cited By ~ 7

Author(s):

Robert J. O'Brien ◽

Bruce E. Dumdei ◽

Susan V. Hummel ◽

Richard A. Yost

Keyword(s):

Mass Spectrometry ◽

Tandem Mass Spectrometry ◽

Degradation Products ◽

Tandem Mass ◽

Atmospheric Degradation

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CHF2CF2OCHF2: conformational analysis and direct dynamics study of its reaction with Cl atoms and atmospheric fate

New Journal of Chemistry ◽

10.1039/c9nj06069c ◽

2020 ◽

Vol 44 (11) ◽

pp. 4276-4284 ◽

Cited By ~ 1

Author(s):

Bidisha Baidya ◽

Makroni Lily ◽

Dimpal Patgiri ◽

Shemphang Hynniewta ◽

Asit K. Chandra

Keyword(s):

Conformational Analysis ◽

Degradation Products ◽

Direct Dynamics ◽

Atmospheric Fate ◽

Atmospheric Degradation ◽

Kinetics Of ◽

Cl Atoms

Conformers of CHF2CF2OCHF2 are identified, and the kinetics of its reaction with Cl atoms and final atmospheric degradation products are studied to assess atmospheric impact.

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A zero-dimensional view of atmospheric degradation of levoglucosan (LEVCHEM_v1) using numerical chamber simulations

10.5194/gmd-2020-189 ◽

2020 ◽

Author(s):

Loredana G. Suciu ◽

Robert J. Griffin ◽

Caroline A. Masiello

Keyword(s):

Gas Phase ◽

Time Scales ◽

Degradation Products ◽

Heterogeneous Reaction ◽

Chemical Degradation ◽

Secondary Products ◽

Modeling Framework ◽

Fire Plumes ◽

Atmospheric Degradation ◽

Degradation Time

Abstract. Here we developed a zero-dimensional (0-D) modeling framework (LEVCHEM_v1) to provide insights into the atmospheric degradation of a key tracer emitted during biomass burning – levoglucosan (LEV), while additionally exploring its effects on the dynamics of secondary organic aerosols (SOA) and other gases. For this, we updated existing chemical mechanisms (homogeneous gas-phase chemistry and heterogeneous chemistry) in the BOXMOXv1.7 model to include the chemical degradation of LEV and its intermediary degradation products in both phases (gas and aerosol). In addition, we added a gas-particle partitioning mechanism to the model to account for the effect of evaporation and condensation on the phase-specific concentrations of LEV and its degradation products. Comparison of simulation results with measurements from various chamber experiments show that the degradation time scale of LEV varied by phase, with degradation occurring over ~ 1.5–3.5 days and aerosol-phase degradation occurring over ~ 8–21 hours. These relatively short time scales suggest that most of the initial LEV concentration can be lost chemically or deposited locally before being transported regionally. We varied the heterogeneous reaction rate constant in a sensitivity analysis and found that longer degradation time scales of LEV are possible in the gas phase (5 days) and the aerosol phase (7 days), implying that some LEV may be transported regionally. The multiphase chemical degradation of LEV has effects on SOA and other gases. Several first- or second-generation products resulted from its degradation; most of the products include one or two carbonyl groups, one product contains a nitrate group, and a few products show the cleavage of C-C bonds. The relative importance of the products varies depending on the phase and the timing of the maximum concentration achieved during the simulation. Our estimated secondary organic aerosol SOA yields (5–32 %) reveal that conversion of LEV to secondary products is significant and occurs rapidly in the studied scenarios. LEV degradation affected other gases by increasing the concentrations of radicals and decreasing those of reactive nitrogen species. Decreases of the mixing ratios of nitrogen oxides appear to drive a more rapid increase in ozone compared to changes in volatile organic compounds (VOC) levels. An important next step to confirm longer degradation time scales will be to extend the evaluation of the modeled LEV degradation beyond 3–5 hours, by using more extensive data from chambers, and, possibly from fire plumes. The mechanism developed here can be used in chemical transport models applied to fire plumes to trace LEV and its degradation products from source to deposition, assess their atmospheric implications and answer questions relevant to fire tracing, carbon and nitrogen cycling, and climate.

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Collagen degradation products modulate matrix metalloproteinase expression in cultured articular chondrocytes

Journal of Orthopaedic Research® ◽

10.1002/jor.20001 ◽

2005 ◽

Vol 24 (1) ◽

pp. 63-70 ◽

Cited By ~ 54

Author(s):

M. Fichter ◽

U. Körner ◽

J. Schömburg ◽

L. Jennings ◽

A. A. Cole ◽

...

Keyword(s):

Matrix Metalloproteinase ◽

Articular Chondrocytes ◽

Degradation Products ◽

Collagen Degradation ◽

Collagen Degradation Products

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Structural Studies of Fibrinolysis by Electron and Light Microscopy

Thrombosis and Haemostasis ◽

10.1055/s-0037-1615843 ◽

1999 ◽

Vol 82 (08) ◽

pp. 277-282 ◽

Cited By ~ 37

Author(s):

Yuri Veklich ◽

Jean-Philippe Collet ◽

Charles Francis ◽

John W. Weisel

Keyword(s):

Electron Microscopy ◽

Light Microscopy ◽

Plasminogen Activator ◽

Structural Changes ◽

Molecular Mechanisms ◽

Degradation Products ◽

Molecular Model ◽

Three Dimensional ◽

Tissue Type ◽

Type Plasminogen Activator

IntroductionMuch is known about the fibrinolytic system that converts fibrin-bound plasminogen to the active protease, plasmin, using plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator. Plasmin then cleaves fibrin at specific sites and generates soluble fragments, many of which have been characterized, providing the basis for a molecular model of the polypeptide chain degradation.1-3 Soluble degradation products of fibrin have also been characterized by transmission electron microscopy, yielding a model for their structure.4 Moreover, high resolution, three-dimensional structures of certain fibrinogen fragments has provided a wealth of information that may be useful in understanding how various proteins bind to fibrin and the overall process of fibrinolysis (Doolittle, this volume).5,6 Both the rate of fibrinolysis and the structures of soluble derivatives are determined in part by the fibrin network structure itself. Furthermore, the activation of plasminogen by t-PA is accelerated by the conversion of fibrinogen to fibrin, and this reaction is also affected by the structure of the fibrin. For example, clots made of thin fibers have a decreased rate of conversion of plasminogen to plasmin by t-PA, and they generally are lysed more slowly than clots composed of thick fibers.7-9 Under other conditions, however, clots made of thin fibers may be lysed more rapidly.10 In addition, fibrin clots composed of abnormally thin fibers formed from certain dysfibrinogens display decreased plasminogen binding and a lower rate of fibrinolysis.11-13 Therefore, our increasing knowledge of various dysfibrinogenemias will aid our understanding of mechanisms of fibrinolysis (Matsuda, this volume).14,15 To account for these diverse observations and more fully understand the molecular basis of fibrinolysis, more knowledge of the physical changes in the fibrin matrix that precede solubilization is required. In this report, we summarize recent experiments utilizing transmission and scanning electron microscopy and confocal light microscopy to provide information about the structural changes occurring in polymerized fibrin during fibrinolysis. Many of the results of these experiments were unexpected and suggest some aspects of potential molecular mechanisms of fibrinolysis, which will also be described here.

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Fibrinogen Bastia (γ 318 Asp → Tyr) a Novel Abnormal Fibrinogen Characterized by Defective Fibrin Polymerization

Thrombosis and Haemostasis ◽

10.1055/s-0037-1614892 ◽

1999 ◽

Vol 82 (12) ◽

pp. 1639-1643 ◽

Cited By ~ 9

Author(s):

Karim Chabane Lounes ◽

Claudine Soria ◽

Antoine Valognes ◽

Marie France Turchini ◽

Jaap Koopman ◽

...

Keyword(s):

Calcium Ions ◽

Clinical Symptoms ◽

Degradation Products ◽

Base Substitution ◽

Chain Gene ◽

Fibrinogen Concentration ◽

Clotting Time ◽

Terminal Part ◽

Fibrin Polymerization ◽

Chain Sequence

SummaryA new congenital dysfibrinogen, Fibrinogen Bastia, was discovered in a 20-year-old woman with no clinical symptoms. The plasma thrombin-clotting time was severely prolonged. The functional plasma fibrinogen concentration was low (0.2 mg/ml), whereas the immunological concentration was normal (2.9 mg/ml). Purified fibrinogen Bastia displayed a markedly prolonged thrombin-clotting time related to a delayed thrombin-induced fibrin polymerization. Both the thrombin-clotting time and the fibrin polymerization were partially corrected by the addition of calcium ions. The anomaly of fibrinogen Bastia was found to be located in the γ-chain since by SDS-PAGE performed according to the method of Laemmli two γ-chains were detected, one normal and one with an apparently lower molecular weight. Furthermore, analysis of plasmin degradation products demonstrated that calcium ions only partially protect fibrinogen Bastia γ-chain against plasmin digestion, suggesting that the anomaly is located in the C-terminal part of the γ-chain. Sequence analysis of PCR-amplified genomic DNA fragments of the propositus demonstrated a single base substitution (G → T) in the exon VIII of the γ chain gene, resulting in the amino acid substitution 318 Asp (GAC) → Tyr (TAC). The PCR clones were recloned and 50% of them contained the mutation, indicating that the patient was heterozygous. These data indicate that residue Asp 318 is important for normal fibrin polymerization and the protective effect of calcium ions against plasmin degradation of the C-terminal part of the γ-chain.

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A Monoclonal Antibody-Based Enzyme Immunoassay for Fibrin Degradation Products in Plasma

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642777 ◽

1988 ◽

Vol 59 (02) ◽

pp. 310-315 ◽

Cited By ~ 64

Author(s):

P W Koppert ◽

E Hoegee-de Nobel ◽

W Nieuwenhuizen

Keyword(s):

Enzyme Immunoassay ◽

Degradation Products ◽

Blood Clot ◽

Tissue Type ◽

Fibrin Degradation Products ◽

Type Plasminogen Activator ◽

Strong Positive Reaction ◽

Sandwich Type ◽

Capture Antibody

SummaryWe have developed a sandwich-type enzyme immunoassay (EIA) for the quantitation of fibrin degradation products (FbDP) in plasma with a time-to-result of only 45 minutes.* The assay is based on the combination of the specificities of two monoclonal antibodies (FDP-14 and DD-13), developed in our institute. FDP-14, the capture antibody, binds both fibrinogen degradation products (FbgDP) and FbDP, but does not react with the parent fibrin(ogen) molecules. It has its epitope in the E-domain of the fibrinogen molecule on the Bβ-chain between amino acids 54-118. Antibody DD-13 was raised using D-dimer as antigen and is used as a tagging antibody, conjugated with horse-radish peroxidase. A strong positive reaction is obtained with a whole blood clot lysate (lysis induced by tissue-type plasminogen activator) which is used as a standard. The EIA does virtually not detect FbgDP i. e. purified fragments X, Y, or FbgDP generated in vitro in plasma by streptokinase treatment. This indicates that the assay is specific for fibrin degradation products.We have successfully applied this assay to the plasma of patients with a variety of diseased states. In combination with the assay previously developed by us for FbgDP and for the total amount of FbgDP + FbDP (TDP) in plasma, we are now able to study the composition of TDP in patients plasma in terms of FbgDP and FbDP.

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