• Korean Journal of Veterinary Service
• /
• v.28 no.3
• /
• pp.285-294
• /
• 2005

This study was conducted to investigate the extraction method for the determination of organochlorine, organophosphorus and synthetic pyrethroid pesticide residues in beef fat by gas chromatography-mass selective detector(GC-MSD). Twenty one pesticide residues in fat were determined using a simple and rapid procedure based on solid- phase extraction(SPE) clean-up cartridges with octadecyl $(C_{18})-bonded$ porous silica, florisil, $10\%$ deactivated florisil. a tandem $C_{18}$ and florisil and a tandem $C_{18}$ and $10\%$ deactivated florisil. Solvent-solvent extraction using acetonitrile was not satisfied to eliminate fat interference for pesticide residue analysis by GC-MSD, and the recoveries of the method in fat ranged from 16.2 to $57.3\%$ except DDT$(83.2\%)$. The recoveries of SPE methods using a tandem $C_{18}$ and Florisil was $59.6\~123.8\%$ except fenitrothion $(135.2\%)$. the SPE method was verified the satisfactory performance of pre-treatment for pesticide residues analysis in fat by GC-MSD. The efficiency of florisil deactivated with $10\%$ water has been not proved significantly on recoveries of pesticide residues in fat.

• Korean Journal of Environmental Agriculture
• /
• v.3 no.1
• /
• pp.36-44
• /
• 1984

Waters, sediments and crucian carps samples collected bimonthly from Nakdong river during- the period of August 1982 to June 1983 were analyzed for organophosphorus pesticide residues by GLC equipped with a flame photometric detector. Among the environmental samples, IBP, diazinon, phenthoate, parathion, malathion and fenitrothion residues were found only in waters and crucian carps and sediments samples were devoid of the residues. In addition, seasonal variations of the residues in waters and crucian carps were observed. Waters and crucian carps samples collected in August, when pesticides are generally in great demand, contained all the organophosphorus pesticide residues while no organophosphorus were detected in waters and crucian carps samples collected in February, April or December. The most abundant residues in the two environmental samples were diazinon and IBP and residue levels of parathion, malathion and fenitrothion were found extremely low.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.6
• /
• pp.1257-1261
• /
• 2009

We present the theoretical and experimental results of $^{31}P$ NMR and low energy CID MS/MS study of $Hg^{2+}$ binding to fenitrothion (FN). The calculated $^{31}P$ NMR chemical shifts order for FN with $Hg^{2+}$ complex is in good agreement with experimental $^{31}P$ NMR chemical shifts order. The experimental and theoretical $^{31}P$ NMR study of organophosphorus pesticide with $Hg^{2+}$ gives to important information for organophosphorus pesticide metal complexes. ESI-MS and low energy CID MS/MS experiments of $Hg^{2+}$-FN complexes combined with accurate mass measurements give insight into the metal localization and allow unambiguous identification of fragments and hydrolysis products.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.9 no.2
• /
• pp.56-60
• /
• 2011

Purpose: The optimal dose of oximes for use in the treatment of organophosphorus pesticide poisoning has not been conclusively established. In this retrospective study, we assessed the effectiveness of the use of high-dose pralidoxime infusion in treating organophosphorus pesticide poisoning. Methods: From January 1998 to December 2009, 71 patients visited the hospital Emergency Department (ED) as a result of organophosphate pesticide intoxication. All of these patients received an initial bolus of 2 g of pralidoxime as the first step of treatment. Patients who then received continuous infusion of pralidoxime at a dose of 500 mg/hr were entered into study group 1 (low dose), and those treated by continuous infusion of pralidoxime at a dose of 1000 mg/hr were entered into study group 2 (high-dose). Plasma cholinesterase activities for each patient were evaluated at ED arrival and re-evaluated 24 hours after pralidoxime infusion. The effectiveness of the two treatment modalities was gauged by comparing the required duration of mechanical ventilation, time spent in the intensive care unit (ICU) and total time spent in the hospital. Results: The mean duration of mechanical ventilation was $9.98{\pm}6.47$ days for group 1 and $4.39{\pm}6.44$ days for group 2. The respective mean duration of time spent in ICU and the total number of days in the hospital were $16.38{\pm}18.84$ days and $21.87{\pm}20.16$ days for group 1, and $7.83{\pm}9.99$ days and $11.71{\pm}13.53$ days for group 2. Highdose pralidoxime treatment was associated with shorter required durations for mechanical ventilation, ICU and hospital stay. In addition, plasma cholinesterase reactivation rates were higher for those patients receiving high-dose pralidoxime treatment. Conclusion: The results suggest that high-dose pralidoxime treatment has greater efficacy for patients suffering from organophosphorus pesticide poisoning.

• The Korean Journal of Pesticide Science
• /
• v.5 no.1
• /
• pp.30-35
• /
• 2001

Diamondback moth (Plutella xylostella L.) recently became a single worst insect which is not controlled effectively by organophosphorus and carbamate insecticides in Kangwon alpine croplands. The objective of this study was to determine if diamondback moth has developed a resistance to organophosphorus and carbamate insecticides. Resistance of diamondback moth, collected at Keichon, Jangpyong Taebaek, Chunchon, and Hongchon, was determined by the concentration required to kill fifty percent of population, $LC_{50}$. Their response of resistance varied to insecticides and locations: Taebaek populations were 35 and 70 times more resistant to chlorpyrifos and fenitrothion, respectively, than susceptible(S) population. Hongchon populations were 94 and 254 times more resistant to chlorpyrifos and fenitrothion, respectively, than S population. In addition, Chunchon populations were 37 and 19 times more resistant to profenofos and benfuracarb, respectively, than S population. However, the field populations did not differ in resistance to diazinon, phenthoate, flupyrazofos, carbofuran, and furathiocarb. This study show that field populations of diamondback moth found in Kangwon alpine vegetable croplands have developed a resistance and/or multiple resistance to some insecticides, implying that farmers are losing organophosphorus and carbamate insecticide options for selective control in vegetable crops.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.3
• /
• pp.373-377
• /
• 2003

Various groups of industrial and agricultural pollutants (heavy metal ions, cyanides, and pesticides) can be detected by enzymes. Since heavy metal ions inhibit urease, cyanides inhibit peroxidase, organophosphorus and carbamate pesticides inhibit butyrylcholinesterase, these enzymes were co-immobilized into a bovine serum albumin gel on the surface of an ion-sensitive field effect transistor to create a bioprobe that is sensitive to the compounds mentioned above. The sensitivity of the present sensor towards KCN corresponded to $1\;\mu\textrm{M}$ with 1 min of incubation time. The detection limits for Hg(II) ions and the pesticide carbofuran were 0.1 and $0.5\;\mu\textrm{M}$, respectively, when a 10 min sensor incubation time in contaminated samples was chosen. The total time for determining the concentrations of all species mentioned did not exceed 20 min.

• Environmental Mutagens and Carcinogens
• /
• v.21 no.2
• /
• pp.128-134
• /
• 2001

Single cell gel electrophoresis (SCGE) assay, also called comet assay, is a rapid and sensitive method to detect DNA damage in single cell level. To evaluate the DNA damage of lymphocytes of pesticides sprayers, SCGE assay was carried out for 50 pesticides sprayer and 58 control subjects. They were interviewed with structured questionnaire to get the information about the kinds and amount of pesticide. Insecticides and fungicides were predominant among pesticides. Major components of pesticides were organophosphorus, organosulfate, cartap, carbamates, and triazole. Sprayed pesticides were classified into two groups. Group I included organophosphorus, organoarsenic, organotin, tetrazine, triazole and gramoxone, which were known to cause DNA damages. Group II pesticide were carbamates, surfactants, organosulfates, etc., which were not found as DNA damaging agents in scientific documents. Olive tail moments of 100 lymphocytes were measured by KOMET 3.1 program for each person. The means of tail moments were compared between farmers exposed to pesticides and control subjects. Farmers showed higher tail moments than control subjects (2.07$\pm$1.40 vs 1.53$\pm$0.77, p<0.05). The means of tail moments also were compared among group I sprayers (n=36), group II sprayers (n=24) and, control subject, and the means or tail moments were 3.4s$\pm$3.2o, 2.66$\pm$2.20 and 1.53$\pm$0.77 respectively. The difference between means of group I sprayers and controls was statistically significant (p<0.05). In conclusion, this study showed higher DNA damage in farmers exposed to pesticides than control subjects, and comet assay could be useful as a biological monitoring method of genotoxic pesticides for farmers.

• Journal of the Korean Society of Urban Environment
• /
• v.18 no.4
• /
• pp.391-399
• /
• 2018

In this study, Diazinon which is the most widely used organophosphorus pesticides (OPPs) among pesticides was removed by ozone/hydrogen peroxide advanced oxidation process (Peroxone AOP). Diazinon is mainly found in groundwater, drinking water, rivers and ponds that are near agricultural areas using the pesticide. Accumulation of Diazinon on the body in the form of metabolites causes neurotoxicity, confusion, dizziness and vomiting. Diazinon is not easily removed by conventional water treatment processes. This study investigated the Diazinon removal characteristics with OH radicals with strong oxidizing power generated by using ozone and hydrogen peroxide. We determined optimal hydrogen peroxide/ozone injection molar ratio and confirmed the elimination reaction to initial Diazinon concentration, pH and DOC concentration, which are factors influencing the removal efficiency. Domestic researches on pesticide removal in the environment are much less than the cases of overseas. This study is expected to provide a basis for the process design for pesticide removal.

• Journal of Microbiology and Biotechnology
• /
• v.24 no.3
• /
• pp.379-385
• /
• 2014

The purpose of this study was to compare the ability of an engineered Escherichia coli to degrade chlorpyrifos (Cp) using an organophosphorus hydrolase enzyme, encoded in both Flavobacterium sp. ATCC 27551 or Pseudomonas diminuta, by employing the Lpp-OmpA chimera and the N-terminal domain of the ice nucleation protein as anchoring motifs. Tracing of the expression location of the recombinant protein using SDS-PAGE showed the presentation of OPH by both anchors on the outer membrane. This is the first report on the presentation of OPH on the cell surface by Lpp-OmpA under the control of the T7 promoter. The results showed cell growth in the presence of Cp as the sole source of energy, without growth inhibition, and with higher whole-cell activity for both cells harboring plasmids pENVO and pELMO, at approximately 10,342.85 and 10,857.14 U/mg, respectively. Noticeably, the protein displayed by pELMO was lower than the protein displayed by pENVO. It can be concluded that Lpp-OmpA can display less protein, but more functional OPH protein. These results highlight the high potential, of both engineered bacteria, for use in the bioremediation of pesticide-contaminated sources in the environment.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.5
• /
• pp.946-951
• /
• 2008

The opd gene, encoding organophosphorus hydrolase (OPH) from Flavobacterium sp. capable of degrading a wide range of organophosphate pesticides, was surface- and intracellular-expressed in Synechococcus PCC7942, a prime example of photoautotrophic cyanobacteria. OPH was displayed on the cyanobacterial cell surface using the truncated ice nucleation protein as an anchoring motif. A minor fraction of OPH was displayed onto the outermost surface of cyanobacterial cells, as verified by immunostaining visualized under confocal laser scanning microscopy and OPH activity analysis; however, a substantial fraction of OPH was buried in the cell wall, as demonstrated by proteinase K and lysozyme treatments. The cyanobacterial outer membrane acts as a substrate (paraoxon) diffusion barrier affecting whole-cell biodegradation efficiency. After freeze-thaw treatment, permeabilized whole cells with intracellular-expressed OPH exhibited 14-fold higher bioconversion efficiency ($V_{max}/K_m$) than that of cells with surface-expressed OPH. As cyanobacteria have simple growth requirements and are inexpensive to maintain, expression of OPH in cyanobacteria may lead to the development of a low-cost and low-maintenance biocatalyst that is useful for detoxification of organophosphate pesticides.