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K M S Sundaram - One of the best experts on this subject based on the ideXlab platform.

  • liquid chromatographic assay of Aminocarb and fenitrothion in pesticide formulations
    Journal of Liquid Chromatography & Related Technologies, 1997
    Co-Authors: K M S Sundaram
    Abstract:

    Abstract A simple, rapid and robust liquid chromatographic method for the analysis of oil-based and emulsion spray-mixes containing Aminocarb and fenitrothion insecticides is reported. The extracts of the spray-mixes, after necessary method optimization, were analysed using an HP RP-C8 column (200 × 4.6 mm ODS, 5 μm) with UV detection and methanol/water (85/15 v%) as the mobile phase. The linear concentration ranges for Aminocarb and fenitrothion were 0.05 to 5.0 μg and 0.10 to 4.2 μg, respectively. Limit of detection and limit of quantification were 0.04 and 0.08 μg (Aminocarb) and 0.05 and 0.10 μg (fenitrothion), respectively, in 20–4 injection volume. Analysis of different oil-based and emulsion spray-mixes of the two insecticides gave reproducible values with low CV, and agreement between the expected and measured values was good. The method could be modified and adapted for the trace analysis of the analytes from forestry matrices.

  • fate of Aminocarb insecticide in the aquatic components of a mixed wood boreal forest environment after aerial application of two matacil 180 flowable formulations
    Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes, 1996
    Co-Authors: K M S Sundaram
    Abstract:

    Abstract The Aminocarb flowable formulation, Matacil®180F, was mixed in water (180FE) and in an oil‐based diluent (180FO) and both formulations were applied as double applications at 70 g active ingredient (AI) in 1.5 L/ha. An aircraft (TBM Avenger) equipped with 1010 flat fan (Teejet®) nozzles was used to spray the insecticide over a mixed‐wood boreal forest in eastern Canada. The amount deposited (g Al/ha) and percent deposited varied considerably among the four applications. The average amount of Aminocarb deposited (g Al/ha) and the percent of the applied dosage found on the forest floor were 18.1 and 22.9, respectively. The emulsion formulation, 180FE, usually produced a higher deposit on the forest floor and in stream waters than the oil‐based 180FO. The 1 h postspray peak concentrations of Aminocarb found in the stream waters sprayed with 180FO and 180FE were 3.06 and 22.64 ppb, respectively. The residues dissipated rapidly within 24 h. The small amount of the chemical (5.8 ppb) that was found in s...

  • liquid chromatographic method for the determination of nonyl phenol surfactant present in the commercial and spray formulations of Aminocarb matacil insecticide
    Journal of Liquid Chromatography & Related Technologies, 1995
    Co-Authors: K M S Sundaram
    Abstract:

    Abstract A high-performance liquid chromatographic method, using a Partisilř ODS-2 column, a mobile phase consisting of 95 % methanol in water and UV detection at 278 nm, has been developed for the determination of p-nonyl phenol surfactant present in the commercial formulations and spray-mixes of Aminocarb insecticide. Nonyl phenol content in five commercial formulations and four spray-mixes was analysed with good reproducibility after removing the insecticide by alkaline hydrolysis and extracting the surfactant with n-heptane. Minimum quantification limit for the analyte was 0.03 μg in 10−uL injection volume. The method is flexible and should be applicable to analyse a variety of nonionic ethoxylated nonyl phenol surfactants present in many industrial and consumer products.

  • fluorometric determination of Aminocarb and mexacarbate and some of their metabolites by liquid chromatography influence of structural factors on fluorescence intensity
    Journal of Liquid Chromatography & Related Technologies, 1994
    Co-Authors: K M S Sundaram, J Curry
    Abstract:

    Abstract A direct and sensitive high performance liquid chromatographic method with fluorescence detection is reported to identify Aminocarb and mexacarbate and some of their metabolites. The observed detection limits were compared by linking the liquid chromatograph to a variable wavelength UV detector. The separation system consisted of an RP-8 OS (10 μm) 20 cm × 4.6 mm I.D. column and acetonitrile-phosphate (pH 7.2) buffer. The excitation and emission wavelengths of the fluorescence detector were set respectively at 200 and 370 nm. The UV detector was set at 242 and 200 nm for Aminocarb and mexacarbate, respectively. The sensitivity in fluorescence detection was not superior to UV method because of the influence of substituents on the aryl ring on fluorescence intensity. Both methods were found to be adequate for the determination of most of the analytes from natural water at nanogiam levels after necessary extraction and cleanup procedures.

  • high performance liquid chromatographic method for the analysis of Aminocarb mexacarbate and some of their n methylcarbamate metabolites by post column derivatization with fluorescence detection
    Journal of Chromatography A, 1994
    Co-Authors: K M S Sundaram, J Curry
    Abstract:

    Abstract A sensitive and selective high-performance liquid chromatographic method with post-column derivatization, using o-phthalaldehyde and 2-mercaptoethanol, is described for the analysis of Aminocarb, mexacarbate and some of their carbamate metabolites. The separation system consisted of an RP-8 OS (10 μm) 20 cm × 4.6 mm I.D. column, an acetonitrile-water mobile system and a reactor for the hydrolysis of analytes from column effluents and fluorophore formation. The fluorophores were detected at 230 nm (excitation) and 418 nm (emission). The recoveries of the carbamates in spiked natural water at 2 and 20 ng/ml fortification levels ranged from 72.0 to 98.4% with relative standard deviations of 5.0 to 11.5%. The recoveries for spiked forest soil at 20 and 200 ng/g fortification levels ranged from 74.1 to 97.6% with relative standard deviations of 5.8 to 10.7%. Limits of detection and quantification for all the analytes were 0.1 and 0.4 ng in water and soil, respectively.

Michel Fournier - One of the best experts on this subject based on the ideXlab platform.

  • Immunotoxicity of Aminocarb. III: Exposure route-dependent immunomodulation by Aminocarb in mice
    Toxicology, 1995
    Co-Authors: Jacques Bernier, Denis Girard, Krzysztof Krzystyniak, Gaston Chevalier, Bertin Trottier, Denis Nadeau, Marek Rola-pleszczynski, Michel Fournier
    Abstract:

    Aminocarb, a phenylsubstituted methylcarbamate pesticide (4-dimethylamino-3-methyl-N-carbamate; matacil), previously suspected of a relatively low immunotoxic potential, was administered by four different exposure routes to C57BL/6 mice. A single sublethal exposure by oral and dermal routes stimulated humoral immune response at a relatively low dose; 1/256 LD50 of Aminocarb. Intraperitoneal (i.p.) injection decreased the humoral PFC response, whereas inhalation of Aminocarb had no marked effect on peripheral immune status in exposed animals. Thus, i.p. exposure resulted in higher immunotoxicity over oral administration of Aminocarb. Similarly, marked route-related exposure differences in immunomodulatory effects of Aminocarb were noted for mitogenic stimulation of spleen lymphocytes and mixed lymphocyte response. Other indices, such as delayed type hypersensitivity (DTH) and production of interleukin-2 (IL-2) were unchanged. Interestingly, expression of major histocompatibility complex (MHC) class II by purified, lipopolysaccharide (LPS)-stimulated B cells increased equally after i.p. and oral exposures to Aminocarb. Overall, a weak immunosuppressive potential of Aminocarb was concluded, which was possibly due to indirect interaction of the pesticide with the immune system. However, Aminocarb may represent an autoimmunity-inducing toxic.

  • acute pulmonary toxicity of aerosolized oil based Aminocarb insecticide early responses of the pulmonary surfactant
    Inhalation Toxicology, 1993
    Co-Authors: Gaston Chevalier, Krzysztof Krzystyniak, Denis Nadeau, Michel Fournier, Janice Boudreau, Renaud Vincent, Sylvain Lapare, Berlin Trottier
    Abstract:

    AbstractThe pulmonary toxicity of aerosolized oil-formulated Aminocarb (Matacil) insecticide was assessed in acutely treated rats in relation to pulmonary surfactant (SF). Time- and dose-dependent changes in biochemical markers [alkaline phosphatase (AKP), acid phosphatase (ACP), β-N-acetyl glucosaminidase (β-NAG) and lactic dehydrogenase (LDH), protein and phospholipid contents] were analyzed in four pulmonary surfactant compartments: (1) the lavaged lung tissue, (2) the cell-free bronchoalveolar lavage (BAL) and its surfactant subfractions obtained by centrifugation, namely, (3) the common myelin figure (CMF) fraction or surfactant proper and (4) the tubular myelin figure (TMF) fraction. Air control groups were used for comparison for every treatment time period. Aerosol deposition was estimated by mathematical calculation. First, groups of animals were treated for 1 hr with a high-concentration aerosol (134 mg Aminocarb/m3 air; MMAD 3.6 μm; GSD 2.4 μm) and studied at 1, 3, and 14 days postexposure. Aft...

  • acute pulmonary toxicity of aerosolized responses of the pulmonary surfactant oil based Aminocarb insecticide early
    1993
    Co-Authors: Caston Chevalier, Denis Nadeau, Michel Fournier, Janice Boudreau, Renaud Vincent, Sylvain Lapare, Bertin Trottier
    Abstract:

    The pulmonary toxicity of aerosolized oil-formulated Aminocarb (Matacil) insecticide was assessed in acutely treated rats in relation to pulmonary surfactant (SF). Time- and dose-dependent changes in biochemical markers [alkaline phosphatase (AKP), acid phosphatase (ACP), j3-N-acetyl glucosaminidase @-NAG) and lactic dehydrogenase (LDH), protein and phospholipid contents] were analyzed in four pulmonary surfactant compartments: (1) the lavaged lung tissue, (2) the cell-free bronchoalveolar lavage (BAL) and its surfactant subfractions obtained by centrifugation, namely, (3) the common myelin figure (CMF) fraction or surfactant proper and (4) the tubular myelin figure VMF) fraction. Air control groups were used for comparison for every treatment time period. Aerosol deposition was estimated by mathematical calculation. First, groups of animals were treated for 1 hr with a high-concentration aerosol (134 mg Aminocarb/m3 air; MMAD 3.6 pm; GSD 2.4 pm) and studied at 1,3, and 14 days postexposure. After 1 day, AKP selectively showed high and early increases in lung tissue and extracellular SF compartments (BAL and TMF), suggesting stimulated secretion of surfactant. Early damage to deep lung was also indicated by a higher amount of protein and activity of LDH in BAL. Most enzymatic parameters returned to control values with time. Prominent early increases in phospholipid (PL) also suggested increased synthesis of surfactant. Second, rats were exposed for 1 hr to high, intermediate, and low concentrations of the formulation, respectively 134, 39, and 11 mg Aminocarb/m3 air and vehicle only (3153 mg vehicle/m3 air), and studied 3 days after exposure. Lung homogenate AKf: ACf: @-NAG, protein, and PL then demonstrated dose-dependent profiles, while for most parameters in all four compartments, the low concentration appeared to induce no effect. Rats exposed to vehicle only showed the most pronounced changes. AKP uniquely exhibited most significant changes in BAL and to a lesser extent in CMF and TMF subfractions. The biochemical studies were correlated with light and electron microscopic studies of the pulmonary tissues.

J Curry - One of the best experts on this subject based on the ideXlab platform.

  • fluorometric determination of Aminocarb and mexacarbate and some of their metabolites by liquid chromatography influence of structural factors on fluorescence intensity
    Journal of Liquid Chromatography & Related Technologies, 1994
    Co-Authors: K M S Sundaram, J Curry
    Abstract:

    Abstract A direct and sensitive high performance liquid chromatographic method with fluorescence detection is reported to identify Aminocarb and mexacarbate and some of their metabolites. The observed detection limits were compared by linking the liquid chromatograph to a variable wavelength UV detector. The separation system consisted of an RP-8 OS (10 μm) 20 cm × 4.6 mm I.D. column and acetonitrile-phosphate (pH 7.2) buffer. The excitation and emission wavelengths of the fluorescence detector were set respectively at 200 and 370 nm. The UV detector was set at 242 and 200 nm for Aminocarb and mexacarbate, respectively. The sensitivity in fluorescence detection was not superior to UV method because of the influence of substituents on the aryl ring on fluorescence intensity. Both methods were found to be adequate for the determination of most of the analytes from natural water at nanogiam levels after necessary extraction and cleanup procedures.

  • high performance liquid chromatographic method for the analysis of Aminocarb mexacarbate and some of their n methylcarbamate metabolites by post column derivatization with fluorescence detection
    Journal of Chromatography A, 1994
    Co-Authors: K M S Sundaram, J Curry
    Abstract:

    Abstract A sensitive and selective high-performance liquid chromatographic method with post-column derivatization, using o-phthalaldehyde and 2-mercaptoethanol, is described for the analysis of Aminocarb, mexacarbate and some of their carbamate metabolites. The separation system consisted of an RP-8 OS (10 μm) 20 cm × 4.6 mm I.D. column, an acetonitrile-water mobile system and a reactor for the hydrolysis of analytes from column effluents and fluorophore formation. The fluorophores were detected at 230 nm (excitation) and 418 nm (emission). The recoveries of the carbamates in spiked natural water at 2 and 20 ng/ml fortification levels ranged from 72.0 to 98.4% with relative standard deviations of 5.0 to 11.5%. The recoveries for spiked forest soil at 20 and 200 ng/g fortification levels ranged from 74.1 to 97.6% with relative standard deviations of 5.8 to 10.7%. Limits of detection and quantification for all the analytes were 0.1 and 0.4 ng in water and soil, respectively.

Gaston Chevalier - One of the best experts on this subject based on the ideXlab platform.

  • Immunotoxicity of Aminocarb. III: Exposure route-dependent immunomodulation by Aminocarb in mice
    Toxicology, 1995
    Co-Authors: Jacques Bernier, Denis Girard, Krzysztof Krzystyniak, Gaston Chevalier, Bertin Trottier, Denis Nadeau, Marek Rola-pleszczynski, Michel Fournier
    Abstract:

    Aminocarb, a phenylsubstituted methylcarbamate pesticide (4-dimethylamino-3-methyl-N-carbamate; matacil), previously suspected of a relatively low immunotoxic potential, was administered by four different exposure routes to C57BL/6 mice. A single sublethal exposure by oral and dermal routes stimulated humoral immune response at a relatively low dose; 1/256 LD50 of Aminocarb. Intraperitoneal (i.p.) injection decreased the humoral PFC response, whereas inhalation of Aminocarb had no marked effect on peripheral immune status in exposed animals. Thus, i.p. exposure resulted in higher immunotoxicity over oral administration of Aminocarb. Similarly, marked route-related exposure differences in immunomodulatory effects of Aminocarb were noted for mitogenic stimulation of spleen lymphocytes and mixed lymphocyte response. Other indices, such as delayed type hypersensitivity (DTH) and production of interleukin-2 (IL-2) were unchanged. Interestingly, expression of major histocompatibility complex (MHC) class II by purified, lipopolysaccharide (LPS)-stimulated B cells increased equally after i.p. and oral exposures to Aminocarb. Overall, a weak immunosuppressive potential of Aminocarb was concluded, which was possibly due to indirect interaction of the pesticide with the immune system. However, Aminocarb may represent an autoimmunity-inducing toxic.

  • acute pulmonary toxicity of aerosolized oil based Aminocarb insecticide early responses of the pulmonary surfactant
    Inhalation Toxicology, 1993
    Co-Authors: Gaston Chevalier, Krzysztof Krzystyniak, Denis Nadeau, Michel Fournier, Janice Boudreau, Renaud Vincent, Sylvain Lapare, Berlin Trottier
    Abstract:

    AbstractThe pulmonary toxicity of aerosolized oil-formulated Aminocarb (Matacil) insecticide was assessed in acutely treated rats in relation to pulmonary surfactant (SF). Time- and dose-dependent changes in biochemical markers [alkaline phosphatase (AKP), acid phosphatase (ACP), β-N-acetyl glucosaminidase (β-NAG) and lactic dehydrogenase (LDH), protein and phospholipid contents] were analyzed in four pulmonary surfactant compartments: (1) the lavaged lung tissue, (2) the cell-free bronchoalveolar lavage (BAL) and its surfactant subfractions obtained by centrifugation, namely, (3) the common myelin figure (CMF) fraction or surfactant proper and (4) the tubular myelin figure (TMF) fraction. Air control groups were used for comparison for every treatment time period. Aerosol deposition was estimated by mathematical calculation. First, groups of animals were treated for 1 hr with a high-concentration aerosol (134 mg Aminocarb/m3 air; MMAD 3.6 μm; GSD 2.4 μm) and studied at 1, 3, and 14 days postexposure. Aft...

Clara Falqui Cao - One of the best experts on this subject based on the ideXlab platform.