• Bulletin of the Korean Chemical Society
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• v.30 no.2
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• pp.489-492
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• 2009

• YAKHAK HOEJI
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• v.17 no.1
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• pp.41-43
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• 1973

Trace-amounts of Diptered and DDVP in fishes could be separated and identified by thin layer chromatography and gas chromatography with DEGS-H$_{3}$PO$_{4}$ column.

• YAKHAK HOEJI
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• v.16 no.1
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• pp.47-54
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• 1972

O,O-Dimethyl-S-(phthalimido)methylphosphorodithioate (PMP) is changed into phosphine, phosphate, and phosphorothioate, when it is treated with metallic zinc in acidic medium after alkaline hydrolysis. The amount of phosphine evolved is about five times as much in sulfuric acid medium as it is in hydrochloric acid. When one micro mole of hydrolyzed PMP is treated with 8 grams of metallic zinc and 30 ml of 10 N-sulfuric acid, it is changed into 0.42 micro moles of phosphine, 0.14 micro moles of phosphorothioate, and 0.44 micro moles of phosphate.

• Journal of the Korean Institute of Gas
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• v.13 no.4
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• pp.8-14
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• 2009

Dimethyl ether(DME) was synthesized from synthesis gas by a one-step process in which a hybrid catalyst was used. The hybrid catalyst consisted of Cu-ZnO-$Al_2O_3$ for the methanol synthesis reaction and aluminum phosphate or $H_3PO_4$-modified $\gamma$-alumina for the methanol dehydration reaction. The prepared catalysts were characterized by XRD, BET, SEM, FT-IR and $NH_3$-TPD. From the XRD analysis, it was verified that the aluminum phosphate was successfully synthesized. The specific surface areas of the synthesized aluminum phosphates were varied with the ratio of P/Al. The hybrid catalyst in which P/Al ratio of the aluminum phosphate was 1.2 showed the highest CO conversion of 55% and DME selectivity of 70%. There was no remarkable decrease in catalytic activity with the phosphoric acid treatment of $\gamma$-alumina. However, when treated with concentrated phosphoric acid(85%), the catalytic activity and DME selectivity decreased.

• Journal of the Korean Applied Science and Technology
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• v.15 no.3
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• pp.77-84
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• 1998

Two-component polyurethane flame retardant coatings were prepared by blending phosphate-containing modified polyesters(PMPEs) and TDI-adduct. PMPEs were synthesized by polycondensation of dimethyl phenylphosphonate, a flame retardant component, with 1,4-butanediol, adipic acid, and trimethylolpropane. The content of dimethyl phenylphosphonate was varied 10, 15, and 20wt% for the reaction. Various physical properties of these new flame retardant coatings were comparable to non-flame retardant coatings. Coatings with 20wt% dimethyl phenylphosphonate did not burn during the vertical burning test.

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.594-598
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• 2005

Treatment of a solution of $CuCl_2$ in dimethyl phosphate (DMP) with DMSO under nitrogen atmosphere afforded to a light blue fluorescence powder. Slow evaporation of $H_2O$-DMSO solution of this powder resulted in blue-sky crystals of a new polymeric Cu(II) complex, with a unit cell composed of $Cu_2(DMP)_4$(DMSO), (1). The crystal and molecular structure of the complex acquired crystallographically. Compound (1) crystallizes in the monoclinic space group $P2_1$/n with a = 12.8920(11) $\AA$, b = 13.1966(11) $\AA$, c = 14.7926(13) $\AA$, $\alpha$ = 90$^{\circ}$, $\beta$ = 98.943(2)$^{\circ}$, $\gamma$ = 90$^{\circ}$, V= 2486.1(4) ${\AA}^3$, and Z = 4. A square pyramidal environment for the metal center was established by coordination of oxygen atoms of four bridging DMP ligands in the basal positions and binding a tri-centered oxygen atom of DMSO in the apical disposition of Cu(II). The sixth position was also affected by a weak interaction with the sulfur atom of another DMSO. The phosphorous atom in the bridging DMP was arranged in a deformed tetrahedron with (gg) conformation for methyl esters with $C_{2v}$ symmetry.

• 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.14 no.4
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• pp.339-345
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• 1999

The present study was performed to investigate photodegradation rate constants and degradation products of dichlorvos and methidathion by the USEPA method. The two pesticides were very stable in sunlight for 16 days from September 2 to 18, 1998 and humic acid had no sensitizing effect on the photolysis of each pesticide in sunlight. The photolysis rate was fast-est for methidathion, followed by dichlorvos in the presence of UV irradiation. Photodegradation rate constant and half-life of dichlorvos were 0.0208 and 33.3 min, respectively. Photodegradation rate constant and half-life of methidathion were 0.6789 and 1.0min, respectively. The two pesticides were degraded completely in the presence of UV irradiation and UV irradiation with TiO$_2$in about 3 hours. Therefore, it is suggested that UV treatment will be effective for the degradation of pesticides in the process of drinking water purification. In case of dichlorvos and methidathion, UV irradiation with TiO$_2$was more effective for degradation than W irradiation. In order to identify photolysis products, the extracts of degradation products were analyzed by GC/ MS. The mass spectrum of photolysis products of dichlorvos was at m/z 153, those of the photolysis of methidathion were at m/z 198 and 214, respectively. Photolysis products of dichlorvos was Ο, Ο-dimethyl phosphate(DMP), those of methidathion were Ο, Ο-dimethyl phosphorothioate(DMTP) and Ο, Ο-dimethyl phosphorodithioate (DMDTP).

• Journal of Environmental Health Sciences
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• v.45 no.6
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• pp.583-593
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• 2019

Objectives: The purpose of this study was to evaluate the relationship between the frequency score of wearing personal protective equipment (PPE) and concentration of urinary organophosphorus pesticide metabolites in farmers. Methods: The study was conducted in Chungcheongnam-do Province of South Korea. We collected urine samples from 308 farmers from September to December 2017 and May to July 2018. Among them, 17 farmers with urinary creatinine levels outside the normal range were excluded. Information on the frequency of wearing PPE was obtained from the farmers through face-to-face survey. Each frequency of wearing for seven types of PPE was converted into a score and expressed as a total score, which was divided into quartiles. Four types of urinary organophosphorus pesticide metabolites were analyzed using a gas chromatography mass selective detector. Multiple linear regression analysis was used to identify concentrations of urinary organophosphorus pesticide metabolites affected by the frequency of wearing PPE. Results: The average frequency score of wearing PPE was 8.0. The quartiles of frequency score of wearing PPE were divided as follows: 1st quartile (≤1), 2nd quartile (1-6), 3rd quartile (6-12), and 4th quartile (>12). Compared with subjects with a low frequency score of wearing PPE (reference), subjects with a high frequency score of wearing PPE (4th quartile) had lower concentrations of urinary diethyl phosphate (DEP) (p<0.01) and dialkyl phosphate (ΣDAP) (p<0.05), which is the sum of dimethyl phosphate (DMP), DEP, dimethyl thiophosphate (DMTP), and diethyl thiophosphate (DETP). Conclusion: Concentrations of urinary organophosphorus pesticide metabolites were associated with frequency score of wearing PPE. Particularly as the frequency score of wearing PPE increased, concentrations of urinary DMP, DEP, DETP, and ΣDAP significantly decreased. The findings of this study can contribute to the management of health effects among farmers working with pesticides.

• 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.