• Korean Journal of Microbiology
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• v.35 no.1
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• pp.61-64
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• 1999

Organophosphorus inseclicide phosphamidon-degrading bacteria were isolated from agricultural soils and identified using Biolog microtiter assay. All Gram-positive degrading bacterial strains belong to genus Bacillus and many Gram-negative bacteria were rare soil species. Among them fast growing strains on phosphamidon-containing minimal medium were sclected and their biodegrading capability wcre measured. YD-17 which was identified as Capnocytophaga gingivalis showed the highest biodegradation rate. It could incrcase the removal of phosphamidon up to 52%. During the biodegradation continuous increase of amount of cell protein was observed, which indicated that phosphamidon was utilized as a carbon source for phosphamidon-degrading bacteria.

• Journal of Environmental Health Sciences
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• v.26 no.2
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• pp.49-58
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• 2000

The present study was performed to investigate photodegradation rate constants and degradation products of phosphamidon and profenofos by the USEPA method. The two pesticides were very stable in 16 days exposure of sunlight from September 3 to 22, 1999 and humic acid had no sensitizing effect on the photolysis of each pesticide in sunlight. In the UV irradiation test, phosphamidon was rapidly degraded as increasing UV intensity. In case of UV irradiation with TiO2 and with TiO2 powder amount, degradation of profenofos showed no significant difference with UV irradiation. Photodegradation rate of profenofos was slower than that of phosphamidon. In order to identify photolysis products, the extracts of degradation products were analyzed by GC/MS. The mass spectra of photolysis products of phosphamidon were at m/z 153 and 149, those of the profenofos were at m/z 208 and 240, respectively. It was suggested that the photolysis products of phosphamidon were 0, 0-dimethyl phosphate(DMP) and N, N-diethylchloroacetamide, those of profenofos were 4-bromo-2-chlorophenol and 0-ethyl-S-propyl phosphate.

• Journal of Food Hygiene and Safety
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• v.15 no.2
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• pp.137-143
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• 2000

The present study was performed to investigate the bioconcentration of phosphamidon and profenofos. The BCFs(bioconcentration factors), depuration rate constants and LC$_{50}$ for two pesticides in zebrafish(Brachydanio rerio) were measured by the flow-through system(OECD guideline 305). The results obtained are summarized as follows: The 24-hrs LC$_{50}$, 48-hrs LC$_{50}$, 72-hrs LC.n and 96-hrs LC$_{50}$ were more than 100 mg/l for phosphamidon. The concentration of phosphamidon in zebrafish reached an equilibrium in 12 hrs at low and high concentrations(0.2 mg/l and 1 mg/1). The average BCF values of phosphamidon were less than 1 at low(0.96, n=7) and high concentrations (0.89, n=7) after 12~168 hrs. Depuration rate constants of phosphamidon were 0.18 hr-1 and 0.21 hr-1, half-life of phosphamidon were 3.85 and 3.30 at low and high concentrations(0.2 mg/l and 1 mg/l), respectively, The concentrations of phosphamidon in zebrafish at low and high concentrations were rapidly decreased after 8(0.04 $\mu\textrm{g}$/g) and 12 hrs(0.07 $\mu\textrm{g}$/g). The 24-hrs LC$_{50}$, 48-hrs LC$_{50}$, 72-hrs LC$_{50}$ and 96-hrs LC$_{50}$ were 2.9, 2.6, 2.2 and 2.0 mg/1 for profenofos. The concentration of profenofos in zebrafish reached an equilibrium in 12 hrs at five-hundredth and one-hundredth concentration of 96-hrs LC$_{50}$(0.004 mgA and 0.02 mg/1). The average BCF values of profenofos were 141.9(n=7) and 111.3(n=7) at five-hundredth and one-hundredth concentration of 96-hrs LC$_{50}$(0.004 mg/l and 0.02 mg/1) after 12~168 hrs. Depuration rate constants of profenofos were 0.09 hr$^{-1}$ and 0.10 hr$^{-1}$, half-life of profenofos were 7.70 and 6.93 at five-hundredth and one-hundredth concentration of 96-hrs LC50(0.004 mg/l and 0.02 mg/1), respectively. The concentrations of profenofos in zebrafish at five-hundredth and one-hundredth concentration of 96-hrs LC$_{50}$ decreased agter 8(0.18 $\mu\textrm{g}$/g) and 12 hrs (0.19 $\mu\textrm{g}$/g). The LC$_{50}$ value in zebrafish showed that acute toxicity of profenofos was higher than that of phosphamidon. The BCF values of profenofos were 100 times higher than those of phosphamidon, and depuration rate of phosphamidon was two times faster than that of profenofos.

• Journal of The Korean Society of Clinical Toxicology
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• v.3 no.1
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• pp.17-21
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• 2005

Purfose: This study was to observe the phosphamidon reduction rate after haemoperfusion (HP) and Hemodialysis (HD) in vitro. Methods: We started off by measuring the clearance of HD and HP for the phosphamidon in vitro. Phosphamidon was measured hourly by High-pressure liquid chromatography. Results: Phosphamidon clearance was effectiveness in HP and HD. Phosphamidon reduction rate was no difference between HD and HP; $64\%$ versus $91.\%1$ at starting, $82.2\%$ versus $80.2\%$ at 1 hours, $82.2\%$ versus $73.8\%$ at 2 hours, $34.4\%$ versus $14.0\%$ at 3 hours, $14.1\%$ versus $27.4\%$ at 4 hours, $0\%$ versus $3.3\%$ at 5 hours. Conculsion: Extracorporeal elimination of phosphamidon is effective by hemoperfusio and hemodialysis in vitro. We suggest hemoperfusion may be effective in organophsphate intoxication patients.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.469-475
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• 1993

In order to elucidate the metabolism of the systemic insecticide, phosphamidon(2-chloro-2-diethylcarbamoyl-1-methylvinyl dimethyl phosphate), treated to pine trees against pine leaf gall midges (Thecodiplosis japonensis Uchida et Inouye), $[vinyl,\;carbonyl-^{14}C]$phosphamidon was implanted into the trunks of 10-year-old Korean red pine (Pinus densiflora Sieb. et Zucc.) and Japanese black pine (Pinus thunbergii Parl.), respectively. This chemical was degraded very quickly in pine trees after implanting, as confirmed by TLC/autoradiography of the extracts of pine needles. Phosphamidon metabolites in phosphate buffer extracts of pine needles include the major metabolite, ${\alpha}-chloroacetoacetic$ acid diethyl-amide, ${\alpha}-chloroacetoacetic$ acid ethylamide, 3-hydroxy-N,N-d iethylbutanamide, acetoacetamide, and trimethyl phosphate. The metabolism within pine trees is expected to be similar to this. Based on these findings, it is believed that the major pathway leading to the metabolites would be related to the P-O-vinyl hydrolysis of the chemical structure.

• Journal of Food Hygiene and Safety
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• v.16 no.2
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• pp.125-132
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• 2001

The present study was conducted to investigate biological degradability of phosphamidon and profenfos. In the biodegradation test of two pesticides by the modified river die-away method from May 20 to July 29, 1999, the biodegradation rate was determined in Nakdong (A) and Kumho(B) River. The residual percentages of phosphamidon were 74.9%, 68.8% and 62.7% in control, A and B samples 7 days after applicaton, respectively. Biodegradation constants and half-lives of phosphamidon were 25.1%, 21.9% and 11.9% in control, A and B samples 7 days after application. Biodegradation constants and half-lives of profenofos were 0.0005 and 58.4 days in A, 0.0013 and 21.6 days in B, respectively. The biodegradation rates of phosphamidon and profenofos were higher in the Kumho River (B) than in the Nackdong River(A). The strains of microorganisms for the degradation of phosphamidon and profenofos were identified as Klebsiella pneumoniae, Aeromonas hydrophila and Acinetobacter calcoaceticus, all Gram-negative bacteria. In order to identify biodegradate products, the extracts of cultivates were analyzed by GC/MS. The mass spectra of biodegradate roducts of phosphamidon were at m/z 153 and 149, those of the profenofos were at m/z 208 and 240, respectively. It was suggested that the biodegradate metabolites of phosphamidon were O, O-dimethyl phosphate(DMP) and N, N-diethylchloroacetamide, those of profenofos were 4-bromo-2-chlorophenol and O-ethyl-S-propyl phosphate.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.463-468
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• 1993

In order to elucidate the translocation of the systemic insecticide, phosphamidon (2-chloro-2-diethylcarbamoyl-1-methylvinyl dimethyl phosphate), treated to pine trees against pine leaf gall midges (Thecodiplosis japonensis Uchida et Inouye), $[vinyl,\;carbonyl-^{14}C]$ phosphamidon was implanted into the trunks of 10-year-old Korean red pine (Pinus densiflora Sieb. et Zucc.) and Japanese black pine (Pinus thunbergii Parl.), respectively. The upward movement rates of the chemical within Korean red pine in July and Japanese black pine in December were ca. 10 cm/hr and 2 cm/hr, respectively. The original radioactivity level persisted up to 75 days after treatment throughout the whole tree in Korean red pine in July, whereas it did up to 150 days in Japanese black pine in December. The chemical was translocated up to the top at the insecticidal level within 3 days after treatment in July, whereas in December it was within 15 days. The translocation of the chemical was much dependent upon pine tree species and the treated season. Methanol was suitable for the extraction of phosphamidon and its metabolites from pine needles. Autoradiography of the methanol extracts of pine needles collected from the treated pine trees proved that phosphamidon broke down very quickly within pine trees (ca. 80% metabolized within 7 days).

• Journal of Food Hygiene and Safety
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• v.15 no.2
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• pp.144-150
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• 2000

The present study was peformed to determine the hydrolysis rate constants and degradation products of phosphamidon and proffnofos by the OECD method. Hydrolysis rate constants of phosphamidon in pH 4, pH 7, and pH 9 buffer solutions at 25 and 40$^{\circ}$C were 0.0020, 0.0022, 0.0049 and 0.0040, 0.0050, 0.0150, respectively. Hydrolysis rate of phosphamidon was accelerated by temprerature change under same pH conditions, and half-life of phosphamidon in pH 9 at 40。C was 3 times faster than that at 25。C. Hydrolysis rate of phosphamidon in alkaline solution(pH 9) was 2~4 times faster than that in acidic solution(pH 4) and neutral solution(pH 7) under same temperature. Hydrolysis rate constants of profenofos in pH 4, pH 7, and pH 9 buffer solutions at 25 and 40。C were 0.0022, 0.0047, 0.0860 and 0.0035, 0.0086, 0.1245, respectively. Hydrolysis rate of profenofos was accelerated by temprerature change under same pH conditions. Hydrolysis rate of profenofos in alkaline solution(pH 9) was 15~40 times faster than in acidic solution(pH 4) and neutral solution(pH 7) under same temperature condition, and half-life of profenofos was very fast within 8 hours. The hydrolysis rate of profenofos was faster than that of phosphamidon. In order to identify hydrolysis products, the extracts of degradation products were analyzed by GC/MS. The mass spectra of hydrolysis products of phosphamidon were at m/z 153 and 149, those of the profenofos were at m/z 208 and 240, respectively. The hydrolysis products of phosphamidon were O, O-dimethyl phosphate(DMP) and N, N-diethylchloroacetamide, and those of profenofos were 4-bromo-2-chlorophenol and O-ethyl-S-propyl phosphate.

• Journal of The Korean Society of Clinical Toxicology
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• v.16 no.1
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• pp.1-8
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• 2018

Purpose: Extremely hazardous pesticides are classified as World Health Organization (WHO) hazard class Ia. However, data describing the clinical course of WHO class Ia OP (organophosphate) poisonings in humans are very scarce. Here, we compare the clinical features of patients who ingested hazard class Ia OPs. Methods: This retrospective observational case study included 75 patients with a history of ingesting ethyl p-nitrophenol thio-benzene phosphonate (EPN), phosphamidon, or terbufos. The patients were divided according to the chemical formulation of the ingested OP. Data regarding mortality and the development of complications were collected and compared among groups. Results: There were no differences in the baseline characteristics and severity scores at presentation between the three groups. No fatalities were observed in the terbufos group. The fatality rates in the EPN and phosphamidon groups were 11.8% and 28.6%, respectively. Patients poisoned with EPN developed respiratory failure later than those poisoned with phosphamidon and also tended to require longer mechanical ventilatory support than phosphamidon patients. The main cause of death was pneumonia in the EPN group and hypotensive shock in the phosphamidon group. Death occurred later in the EPN group than in the phosphamidon group. Conclusion: Even though all three drugs are classified as WHO class Ia OPs (extremely hazardous pesticides), their clinical courses and the related causes of death in humans varied. Their treatment protocols and predicted outcomes should therefore also be different based on the chemical formulation of the OP.

• The Korean Journal of Pesticide Science
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• v.12 no.3
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• pp.262-269
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• 2008

This study was performed to investigate the toxicity of 39 registered insecticides to the susceptibility, systemic effect, and residual effect and control effect against Pine sawyer beetle, Monochamus saltuarius. Eleven kinds of chemicals such as fenitrothion, fenthion, phenthoate, phosphamidon, dinotefuran, actamiprid, clothianidin, thiacloprid, thiamethoxam, esfenvalerate+fenitrothion, and fipronil were showed 100% insecticidal activity both in body spray and twig dipping bioassay. Among these chemicals, fenitrothion and fenthion were showed 100% insecticidal activity when sprayed at 4000 times diluted solutions, and phenthoate, thiacloprid, thiamethoxam and fipronil were showed 100% insecticidal activity when sprayed at 2000 times diluted solution. Root systemic effect was showed 100% mortality in phosphamidon, clothianidin, thiamethoxam, and 77.7% in thiacloprid. In residual effect, fenitrothion and thiamethoxam were showed 80% mortality fifteen days after treatment (DAT), and fenthion, phosphamidon, clothianidin were showed 80% mortality ten DAT, fenitrothion, thiamethoxam, fipronil showed 100% mortality in seven DAT, thiacloprid was showed 100% mortality in three DAT. Fenthion and phenthoate were showed 100% mortality one DAT. In the control effect, 6 kinds of chemicals were showed 100% mortality one DAT and all chemicals showed 100% mortality three DAT.