scholarly journals Conjugations of Carbaryl in Insects

2021 ◽  
Author(s):  
◽  
Michael Perry Heenan
Keyword(s):  
Isotope Dilution ◽  
Water Soluble ◽  
Oxidation Products ◽  
Dihydrogen Phosphate ◽  
Primary Metabolites ◽  
Hydrogen Sulphate

<p>The conjugation of carbaryl and its initial breakdown products in insects has been examined. Houseflies, blowflies and grass grubs were dosed with [3 H] carbaryl and the water-soluble metabolites examined by a combination of paper chromatographic and ionophoretic techniques. These revealed the presence of 1-naphthyl dihydrogen phosphate, 1-naphtyl hydrogen sulphate and 1-naphthyl Beta-D-glucoside in the extracts, as well as at least seven other unidentified substances, probably including the phosphate, sulphate and glucoside conjugates of oxidation products of carbaryl. The conjugation of 1-naphthol, one of the primary metabolites of carbaryl, was examined in greater detail in flies and grass grubs. Isotope dilution and paper chromatographic analyses of extracts of insects dosed with [14 C]1-naphthol revealed the presence of the phosphomonoester, sulphate, and glucoside conjugate of 1-naphthol, but phosphodiester and glucosiduronic acid conjugates could not be detected. A new metabolite of 1-naphthol was present in extracts of dosed flies. This new metabolite, and also the corresponding p-nitrophenol metabolite, was isolated form extracts of flies fed with the parent phenols and characterised as a new conjugate, the Beta-D-glucoside 6-(dihydrogen phosphate). Some of the properties of this new conjugate were determined. 1-Naphthyl Beta-D-glucoside 6-phosphate probably accounted for one of the unidentified carbaryl conjugates.</p>

scholarly journals Conjugations of Carbaryl in Insects

2021 ◽  
Author(s):  
◽  
Michael Perry Heenan
Keyword(s):  
Isotope Dilution ◽  
Water Soluble ◽  
Oxidation Products ◽  
Dihydrogen Phosphate ◽  
Primary Metabolites ◽  
Hydrogen Sulphate

<p>The conjugation of carbaryl and its initial breakdown products in insects has been examined. Houseflies, blowflies and grass grubs were dosed with [3 H] carbaryl and the water-soluble metabolites examined by a combination of paper chromatographic and ionophoretic techniques. These revealed the presence of 1-naphthyl dihydrogen phosphate, 1-naphtyl hydrogen sulphate and 1-naphthyl Beta-D-glucoside in the extracts, as well as at least seven other unidentified substances, probably including the phosphate, sulphate and glucoside conjugates of oxidation products of carbaryl. The conjugation of 1-naphthol, one of the primary metabolites of carbaryl, was examined in greater detail in flies and grass grubs. Isotope dilution and paper chromatographic analyses of extracts of insects dosed with [14 C]1-naphthol revealed the presence of the phosphomonoester, sulphate, and glucoside conjugate of 1-naphthol, but phosphodiester and glucosiduronic acid conjugates could not be detected. A new metabolite of 1-naphthol was present in extracts of dosed flies. This new metabolite, and also the corresponding p-nitrophenol metabolite, was isolated form extracts of flies fed with the parent phenols and characterised as a new conjugate, the Beta-D-glucoside 6-(dihydrogen phosphate). Some of the properties of this new conjugate were determined. 1-Naphthyl Beta-D-glucoside 6-phosphate probably accounted for one of the unidentified carbaryl conjugates.</p>

scholarly journals Development of a versatile source apportionment analysis based on positive matrix factorization: a case study of the seasonal variation of organic aerosol sources in Estonia

2019 ◽  
Vol 19 (11) ◽  
pp. 7279-7295 ◽  
Author(s):  
Athanasia Vlachou ◽  
Anna Tobler ◽  
Houssni Lamkaddam ◽  
Francesco Canonaco ◽  
Kaspar R. Daellenbach ◽  
...  
Keyword(s):  
Matrix Factorization ◽  
Organic Aerosol ◽  
Positive Matrix Factorization ◽  
Water Soluble ◽  
Oxidation Products ◽  
Positive Matrix ◽  
Bootstrap Analysis ◽  
Seasonal Behavior ◽  
Yearly Cycle ◽  
Aerosol Mass

Abstract. Bootstrap analysis is commonly used to capture the uncertainties of a bilinear receptor model such as the positive matrix factorization (PMF) model. This approach can estimate the factor-related uncertainties and partially assess the rotational ambiguity of the model. The selection of the environmentally plausible solutions, though, can be challenging, and a systematic approach to identify and sort the factors is needed. For this, comparison of the factors between each bootstrap run and the initial PMF output, as well as with externally determined markers, is crucial. As a result, certain solutions that exhibit suboptimal factor separation should be discarded. The retained solutions would then be used to test the robustness of the PMF output. Meanwhile, analysis of filter samples with the Aerodyne aerosol mass spectrometer and the application of PMF and bootstrap analysis on the bulk water-soluble organic aerosol mass spectra have provided insight into the source identification and their uncertainties. Here, we investigated a full yearly cycle of the sources of organic aerosol (OA) at three sites in Estonia: Tallinn (urban), Tartu (suburban) and Kohtla-Järve (KJ; industrial). We identified six OA sources and an inorganic dust factor. The primary OA types included biomass burning, dominant in winter in Tartu and accounting for 73 % ± 21 % of the total OA, primary biological OA which was abundant in Tartu and Tallinn in spring (21 % ± 8 % and 11 % ± 5 %, respectively), and two other primary OA types lower in mass. A sulfur-containing OA was related to road dust and tire abrasion which exhibited a rather stable yearly cycle, and an oil OA was connected to the oil shale industries in KJ prevailing at this site that comprises 36 % ± 14 % of the total OA in spring. The secondary OA sources were separated based on their seasonal behavior: a winter oxygenated OA dominated in winter (36 % ± 14 % for KJ, 25 % ± 9 % for Tallinn and 13 % ± 5 % for Tartu) and was correlated with benzoic and phthalic acid, implying an anthropogenic origin. A summer oxygenated OA was the main source of OA in summer at all sites (26 % ± 5 % in KJ, 41 % ± 7 % in Tallinn and 35 % ± 7 % in Tartu) and exhibited high correlations with oxidation products of a-pinene-like pinic acid and 3-methyl-1, 2, 3-butanetricarboxylic acid (MBTCA), suggesting a biogenic origin.

scholarly journals Ion Mobility Spectrometry-Mass Spectrometry (IMS-MS) for on- and off-line analysis of atmospheric gas and aerosol species

2016 ◽  
Author(s):  
Jordan E. Krechmer ◽  
Michael Groessl ◽  
Xuan Zhang ◽  
Heikki Junninen ◽  
Paola Massoli ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ion Mobility Spectrometry ◽  
Ion Mobility ◽  
Measurement Techniques ◽  
Molecular Ions ◽  
Molecular Structures ◽  
Water Soluble ◽  
Oxidation Products ◽  
Time Resolved ◽  
Organic Species

Abstract. Measurement techniques that provide molecular-level information are needed to elucidate the multi-phase processes that produce secondary organic aerosol (SOA) species in the atmosphere. Here we demonstrate the application of ion mobility spectrometry-mass spectrometry (IMS-MS) to the simultaneous characterization of the elemental composition and molecular structures of organic species in the gas and particulate phases. Molecular ions of gas-phase organic species are measured online with IMS-MS after ionization with a custom build nitrate chemical ionization (CI) source. This CI-IMS-MS technique is used to obtain time-resolved measurements (5 min) of highly oxidized organic molecules during the 2013 Southern Oxidant and Aerosol Study (SOAS) ambient field campaign in the forested SE US. The ambient IMS-MS signals are consistent with laboratory IMS-MS spectra obtained from single-component carboxylic acids and multicomponent mixtures of isoprene and monoterpene oxidation products. Mass-mobility correlations in the 2-dimensional IMS-MS space provide a means of identifying ions with similar molecular structures within complex mass spectra and are used to separate and identify monoterpene oxidation products in the ambient data that are produced from different chemical pathways. Water-soluble organic carbon (WSOC) constituents of fine aerosol particles that are not resolvable with standard analytical separation methods, such as liquid chromatography (LC), are shown to be separable with IMS-MS coupled to an electrospray ionization (ESI) source. The capability to use ion mobility to differentiate between isomers is demonstrated for organosulfates derived from the reactive uptake of isomers of isoprene epoxydiols (IEPOX) onto wet acidic sulfate aerosol. Controlled fragmentation of precursor ions by collisional dissociation (CID) in the transfer region between the IMS and the MS is used to validate MS peak assignments, elucidate structures of oligomers, and confirm the presence of the organosulfate functional group.

scholarly journals Molecular Distributions of Soluble Oxidation Products from Coals Characterized by Mass Spectrometers

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xing Fan ◽  
Fei Wang
Keyword(s):  
Mass Spectrometry ◽  
Direct Analysis ◽  
Water Soluble ◽  
Oxidation Products ◽  
Gas Chromatography Mass Spectrometry ◽  
Mass Spectrometers ◽  
Polycarboxylic Acids ◽  
Alkanoic Acids ◽  
Carboxylic Groups ◽  
Soluble Species

Oxidation of three coals with rank from lignite to anthracite in NaOCl aqueous solution was investigated in this study. The oxidation products were characterized by using gas chromatography/mass spectrometry and direct analysis in real-time mass spectrometry. The results showed that most of organic compounds in coals were converted into water-soluble species under mild conditions, even the anthracite. Benzene polycarboxylic acids (BPCAs) and chloro-substituted alkanoic acids (CSAAs) were major products from the reactions. The products from lower rank coals consist of considerable CSAAs and most products from high rank coals are BPCAs. As coal rank increases, the yield of BPCAs with more carboxylic groups increases.

scholarly journals Chemical insights, explicit chemistry, and yields of secondary organic aerosol from OH radical oxidation of methylglyoxal and glyoxal in the aqueous phase

2013 ◽  
Vol 13 (17) ◽  
pp. 8651-8667 ◽  
Author(s):  
Y. B. Lim ◽  
Y. Tan ◽  
B. J. Turpin
Keyword(s):  
Acetic Acid ◽  
Aqueous Phase ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Water Soluble ◽  
Oxidation Products ◽  
Radical Reactions ◽  
Organic Radical ◽  
Oh Radical ◽  
Radical Oxidation

Abstract. Atmospherically abundant, volatile water-soluble organic compounds formed through gas-phase chemistry (e.g., glyoxal (C2), methylglyoxal (C3), and acetic acid) have great potential to form secondary organic aerosol (SOA) via aqueous chemistry in clouds, fogs, and wet aerosols. This paper (1) provides chemical insights into aqueous-phase OH-radical-initiated reactions leading to SOA formation from methylglyoxal and (2) uses this and a previously published glyoxal mechanism (Lim et al., 2010) to provide SOA yields for use in chemical transport models. Detailed reaction mechanisms including peroxy radical chemistry and a full kinetic model for aqueous photochemistry of acetic acid and methylglyoxal are developed and validated by comparing simulations with the experimental results from previous studies (Tan et al., 2010, 2012). This new methylglyoxal model is then combined with the previous glyoxal model (Lim et al., 2010), and is used to simulate the profiles of products and to estimate SOA yields. At cloud-relevant concentrations (~ 10−6 − ~ 10−3 M; Munger et al., 1995) of glyoxal and methylglyoxal, the major photooxidation products are oxalic acid and pyruvic acid, and simulated SOA yields (by mass) are ~ 120% for glyoxal and ~ 80% for methylglyoxal. During droplet evaporation oligomerization of unreacted methylglyoxal/glyoxal that did not undergo aqueous photooxidation could enhance yields. In wet aerosols, where total dissolved organics are present at much higher concentrations (~ 10 M), the major oxidation products are oligomers formed via organic radical–radical reactions, and simulated SOA yields (by mass) are ~ 90% for both glyoxal and methylglyoxal. Non-radical reactions (e.g., with ammonium) could enhance yields.

Synthesis of fire retardants based on N and P and poly(sodium silicate-aluminum dihydrogen phosphate) (PSADP) and testing the flame-retardant properties of PSADP impregnated poplar wood

Holzforschung ◽  
2016 ◽  
Vol 70 (4) ◽  
pp. 341-350 ◽  
Author(s):  
Xiaoteng Zhang ◽  
Jun Mu ◽  
Demiao Chu ◽  
Yang Zhao
Keyword(s):  
Sodium Silicate ◽  
Synergistic Effects ◽  
Water Soluble ◽  
Dihydrogen Phosphate ◽  
Poplar Wood ◽  
Fire Retardants ◽  
Combustion Heat ◽  
Flame Retardant Properties ◽  
Wood Surfaces ◽  
Nitrogen Phosphorus

Abstract The development of fire retardants (FRs) is an approximative process of optimization. In this context, a novel water-soluble formulation with poly(sodium silicate-aluminum dihydrogen phosphate) (PSADP) has been developed, aiming at reduced hygroscopicity and enhanced leaching resistance of poplar wood in combination with nitrogen-phosphorus (NP) FR (FRNP). After treatment of wood with FRNP and PSADP in vacuum, the following data of the samples were determined: rate of hydroscopicity, leaching resistance, heat release rate (HRR), total HR (THR), effective combustion heat, mass loss, and concentration of flue gas. FR distribution in the wood’s inner surface was investigated by scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDXA). Results show that PSADP and FRNP have favorable synergistic effects on moisture resistance and flame retardance. Smoke density (SD) of NP and PSADP treated samples shows a significant reduction relative to that of NP. NP-PSADP treated samples form more char with carbon layers of higher density. At the same time, FRNP-PSADP is evenly distributed over the inner wood surfaces and penetrates the cell cavities of the poplar wood.

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