• Applied Biological Chemistry
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• v.26 no.2
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• pp.97-103
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• 1983

To get further information on the behavior of phorate(0,0-diethyl S-ethylthiomethyl phosphorodithioate) in soil under the subtropical conditions, a field experiment has been conducted. Phorate granule (10%) was applied to silt loam soil at the rate of 40kg a.i./ha and incorporated to 10cm soil depth. Residues of phorate and its metabolites in soil were determined with GLC and confirmed qualitatively with TLC. Phorate was rapidly oxidized to its sulfoxide and sulfone. Therefore, main metabolic pathway of phorate in soil was the oxidation of phorate to phorate sulfoxide and sulfone. Phorate sulfoxide and sulfone were relatively more persistent than phorate itself. Phoratoxon was detected at low level only up to 30 days after treatment and its sulfoxide and sulfone were not detected during the whole experimental period. Toluene-acetonitrile-nitromethane(40 : 30 : 30, v/v/v) solvent system separated satisfactorily phorate and its five metabolites. Most of the residues was found in the initial incorporation depth $(0{\sim}10cm)$. Consequently, insecticides showed a little downward movement.

• Korean Journal of Environmental Agriculture
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• v.6 no.2
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• pp.77-83
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• 1987

Present study was carried out to elucidate the effect of phorate (0,0-dietyl S-ethylthiomethyl phosphorodithioate), an organophosphorus insecticide on the acetylcholinesterase(AChE) and cholinesterase(ChE) activity in the chicken brain and plasma. The inhibitory effect of phorate and its metabolites on AChE and ChE activity was also increased in the order of phorate (p=S,S)$(p=S,SO_2)<phoratoxon$ (p=O,S)$(P=O,SO_2)$. Acute oral $LD_{50}$ of phorate was 1.02mg/kg. After oral administration of phorate, the activity of plasma ChE was inhibited more rapidly then that of brain AChE, whereas recovery of plasma ChE activity was more rapid than that of brain AChE activity.

• Korean Journal of Environmental Agriculture
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• v.3 no.1
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• pp.10-15
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• 1984

To get information on the behavior of phorate in vegetables under the subtropical conditions, phorate granule (10%) was applied to silt loam soil at the rate of 40㎏ a.i./ha and incorporated to 10㎝ soil depth just befere sowing. Insecticide residues in vegetables were determined with GLC and confirmed qualitatively with TLC. Phorate and its metabolites were absorbed by the radish and carrot roots and rapidly translocated into foliages. The compounds detected in vegetables were phorate, phorate sulfoxide, and phorate sulfone. Residue levels of compounds in radishes were higher in foliages than in roots and much more residues were present in leaf lamina than in midribs. The concentration of the total residues in vegetable roots was rapidly decreased with the time, while the amount of total residues in radish roots was increased with the time. Therefore, the rapid decline of residue levels in vegetables was mainly attributed to the dilution of insecticide residues by the rapid growth of these vegetables.

• Applied Biological Chemistry
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• v.26 no.2
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• pp.104-109
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• 1983

Gas chromatographic method for the analysis of phorate(0,0-diethyl S-ethyl-thiomethyl phosphorithioate) and its metabolites in soil and vegetables was studied by using a mixed phase column(10% DC-200+8% Reoplex-400+2% QF-1 on Gas Chrom Q, $1.8{\times}2mm$ i.d, borosilicate glass column). This column can separate completely phorate and its four metabolites except phoratoxon sulfoxide. Retention time of standard mixture ranged 1.8 to 16.1 minutes at column temperature programming from 130 to $200^{\circ}C$ at $5^{\circ}C/min$ and detector sensitivity was also very high(0.05 to 1.05ng). Recoveries from soil and vegetables untreated but fortified with phorate and its three major metabolites at 0.05 and 0.5ppm levels were above 90% for phorate, phorate sulfoxide and phorate sulfone while recovery of phoratoxon metabolite was about 84%.

• Applied Biological Chemistry
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• v.40 no.4
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• pp.323-328
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• 1997

Runoff of phorate, soil insecticide, were measured under simulated rainfall conditions in field using small test plot$(120\;cm{\times}120\;cm)$ at the loam area and loamy sand area. Fish acute toxicity tests were performed with runoff water to elucidate its toxicological effect on organisms in ecosystem. The average concentrations of phorate in runoff water from loam and loamy sand soil were 11.3 ppb and 4.8 ppb, respectively. However, there was no significant concentration difference between the heavy and the light rain. With loam soil, average runoff rates were 1.31 and 0.18%, while with loamy sand soil those were 0.48 and 0.012% under the heavy and the light rain conditions, respectively. Total average runoff rate was 0.50%. With killifish, no mortality was observed in runoff water from loamy sand soil, whereas half of the population was dead in runoff water from loam soil when it was diluted to 54.4% content.

• Journal of Food Hygiene and Safety
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• v.30 no.3
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• pp.272-280
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• 2015

A simultaneous official method was developed for the determination of phorate and its metabolites (phorate sulfoxide, phorate sulfone, phorate oxon, phorate oxon sulfoxide, phorate oxon sulfone) in livestock samples. The analytes were quantified and confirmed via liquid chromatograph-tandem mass spectrometer (LC-MS/MS) in positive ion mode using multiple reaction monitoring (MRM). Phorate and its metabolites were extracted from beef and milk samples with acidified acetonitrile (containing 1% acetic acid) and partitioned with anhydrous magnesium sulfate. Then, the extract was purified through primary secondary amine (PSA) and C18 dispersive sorbent. Matrix matched calibration curves were linear over the calibration ranges (0.005-0.5 mg/L) for all the analytes into blank extract with $r^2$ > 0.996. For validation purposes, recovery studies were carried out at three different concentration levels (beef 0.004, 0.04 and 0.2 mg/kg; milk 0.008, 0.04 and 0.2 mg/kg, n = 5). The recoveries were within 79.2-113.9% with relative standard deviations (RSDs) less than 19.2% for all analytes. All values were consistent with the criteria ranges requested in the Codex guidelines. The limit of quantification was quite lower than the maximum residue limit (MRL) set by the Ministry of Food and Drug Safety (0.05 mg/kg). The proposed analytical method was accurate, effective and sensitive for phorate and its metabolites determination and it will be used to as an official analytical method in Korea.

• Applied Biological Chemistry
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• v.31 no.1
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• pp.92-99
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• 1988

The responses of brain acetylcholinesterase and plasma cholinesterase activities were examined in chicken given oral doses of an organophosphorus insecticides. Acute oral $LD_{50}$ of terbufos was 1.82mg/kg, and terbufos sulfone was 2.85mg/kg, terbufos sulfoxide, terbufoso xon, terbufosoxon sulfone and terbufosoxon sulfoxide were about $0.30{\sim}0.79mg/kg$, respectively. Acute oral $LD_{50}$ of phorate was 1.02mg/kg, and phorate sulfone was 1.73mg/kg, phorate sulfoxide, phoratoxon, phoratoxon sulfoxide and phoratoxon sulfone were about $0.36{\sim}0.63mg/kg$, respectively. Dosages of 50% inhibition for brain AChE and plasma ChE activities in chicken at 60 mins after oral administration of organop hosphorus insecticides were $35.3{\pm}6.8%\;and\;17.4{\pm}3.6%$ of acute oral $LD_{50}$, respectively. Activities of brain AChE and plasma ChE in chicken at 60 mins after oral administratration of acute oral $LD_{50}$ of organophosphorus insecticides were inhibited by $83.7{\pm}3.9%\;and\;93.3{\pm}2.2%$, respectively.

• 월간산업보건
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• s.343
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• pp.24-27
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• 2016

• 월간산업보건
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• s.344
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• pp.25-28
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• 2016

• 월간산업보건
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• s.345
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• pp.40-43
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• 2017