• Journal of the Korean Chemical Society
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• v.39 no.12
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• pp.902-909
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• 1995

Detection limit as well as calibration curves on organophosphorus pesticide(dimethoate, diazinon, parathion-methyl, fenitrothion, malathion) and BHCs were measured for evaluation of utility on qualitative or quantitative analysis of pesticides with ion Trap mass spectrometer and quadrupole mass spectrometer. As ionization source, EI and CI were adopted for qualitative analysis of pesticides by comparison of each fragmentation pattern. At the same time, the utility as trace analysis techniques through scan or selected ion monitoring(SIM) mode was evaluated. With ion trap for all pesticides, detection limit(DL, 1 ${\mu}L$ injection) on scan mode was ranged 0.008∼0.225 ng at signal to noise ratio 3. With quadrupole DL on scan mode was ranged 0.23∼3.1 ng over 0.032∼0.68 ng on SIM mode. The calibration curve with ion trap generated good linearity over 0.99 as correlation coefficient. As clean up procedure, Bio Beads S-X3 was used for the separation of oils from five organophosphorous pesticides in flour extractant showing more than 80% as recovery at most cases. In case of BHCs in jinseng with Florisil column, the recovery of pesticides has been 60% to 90%.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.427-431
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• 1997

A simultaneous and rapid gas chromatographic determination of organophosphorus, organo-chlorine, carbamate, and pyrethroid pesticides in polished rice was developed. The pesticides were extracted from samples with acetone by automated soxhlet apparatus and this extract was evaporated to dryness. The residue was dissolved in hexane, the solvent was applied to a Sep-Pak florisil catridge, was eluted with 50% ethyl acetate in n-hexane, and was injected to dual GC-ECD/NPD system. This simple method affords a high recovery of hydrophilic pesticides, allows rapid analysis, and is cheap to perform. Except for dichlorvos and captan, recoveries of 46 pesticides were over 60%.

• Journal of the Korean Chemical Society
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• v.13 no.2
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• pp.141-147
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• 1969

Organophosphorous compounds can be reduced by zinc metal in acidic solution after alkaline hydrolysis. Although phosphates and phosphonates did not evolve any gas, dithioates did evolve hydrogen sulfide and phosphine, thionates and thiolates did evolve only hydrogen sulfide. The evolved gases were qualitatively detected by means of lead acetate and silver nitrate or mercuric bromide papers and determined by spectrophotometrically. The reduction mechanism and analytical method of dithioates were proposed.

• Journal of the korean veterinary medical association
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• v.6 no.1
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• pp.26-35
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• 1962

A Study on the Treatment of Canine Demodicidosis with Low Toxic Organ Phosphates In this experiment, the treatment of canine demodicidosis with Dipterex(50$\%$ Diethyl trichlorohydroxethyl phosphanate), a kind of low toxic organic phosphates, h

• Journal of the Korean Chemical Society
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• v.31 no.3
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• pp.236-243
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• 1987

The optimum resolution condition of 11 organophosphorus pesticides by gas-liquid chromatography was studied using a capillary column. The injection modes and types of vaporization tubes were evaluated in relation to pesticide analysis. The best reproducibility of peak heights of pesticides was obtained by the split mode with the vaporization tube packed with quartz wool. A 25m SE-30 capillary column provided better resolution than SE-54 column for their optimum resolution. The column at $200^{\circ}C$ initially was heated by $5^{\circ}C/min\;to\;230^{\circ}C$ followed by $10^{\circ}C/min\;to\;270^{\circ}C$ and the temperatures were held constant for 5 minutes at $230^{\circ}C\;and\;270^{\circ}C$, respectively. The relative standard deviations of their retention times were less than 0.19%.

• Journal of Environmental Health Sciences
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• v.23 no.1
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• pp.66-73
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• 1997

This procedure describes the method for gas chromatographic determination of 31 organophosphorus and 28 organochlorine pesticides in 10g of spinach, tomato and onion. After the pesticides were extracted with several solvents, the amount of coextractives and recovery rates of acephate and methamidophos were calculated. Samples for organochlorine pesticides were cleaned up with florisil solid phase extraction columns. NaBH$_4$ was added to onion extracts, which contained sulfur compound. All the concentrated extracts were analyzed by gas chromatography with ECD and NPD. The smallest amount of coextractives resulted from the spinach samples extracted with 5% MeOH in ethyl acetate. 5% EOH in ethyl acetate had the highest extractability for acephate and methamidophos and gave the best overall performance as an extraction solvent. The ability of 5% EOH in ethyl acetate to extract various organophosphorus and organochlorine pesticides from spinach, tomato and onion was examined. Recovery of 59 insecticides ranged from 58.0% to 110.5%. The average recoveries of fortified spinach, tomato and onion were 90.08%, 94.54% and 84.90%, respectively.

• Journal of Food Hygiene and Safety
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• v.11 no.2
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• pp.99-105
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• 1996

An attempt was made to determine the residual distribution of organochlorine and organophosphorus pesticides in the various kinds of Korean tea which were purchased form the maket. The organochlorine pesticides investigated in this study were BHC, DDT and dicofol and the organophoshorus pesticides were diazinon, EPN, fenitrothion and parathion. The pesticide residues were determined by GC-ECD and BHC was detected in all the samples and it's level were ranged from 0.00064 po 0.05995 ppm and it's average was 0.00682 ppm and DDT, dicofol and organophosphorus pesticides were not detected in all samples. The organophophorus pesticides were detected(0.0035∼0.0983 ppm) in raw materials but were not in the manufactured material and it is considered that the largely components of the pesticides is removed by drying and high temperature while the tea was manufactured. The recovery tests of the pesticides gave satisfactory results showing an average yield of 97.6% with organochlorine pesticides and 92.5% with organophoshorus pesticides and the detection limits level were 0.00008 ppm to 0.0010 ppm.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.861-867
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• 2000

The feasibility of simultaneous phosphorus and nitrogen removal by enhancing anoxic phosphorus uptake was investigated in a sequencing batch reactor (SBR). By introducing an anoxic phase into an anaerobic-aerobic SBR (AO SBR), significant amounts of denitrifying phosphorus accumulating organisms (DPAOs) which can utilize nitrate as electron acceptor could be accumulated in the reactor (anaerobic-aerobic- anoxic-aerobic SBR, $(AO)_2$ SBR). A direct comparison of phosphorus uptake rate under anaerobic and aerobic conditions showed that the fraction of DPAOs in P-removing sludge were increased from 10% in the AO SBR to 64% in $(AO)_2$ SBR. The $(AO)_2$ SBR showed stable phosphorus and nitrogen removal efficiency: average removal efficiencies of TOC, total nitrogen, and phosphorus were 92%, 88%, and 100%. respectively. Results of the $(AO)_2$ SBR operation and batch tests showed that nitrite (up to 10 mg-N/L) was not detrimental to anoxic phosphorus uptake and could serve as good electron acceptor like nitrate.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2002.04a
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• pp.66-69
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• 2002

온실의 피복자재는 소재에 따라 분진의 오염정도가 다르다. 또한 세척을 하는 방법도 소재의 특성에 따라 다르게 하여야 한다. 즉 폴리에틸렌이나 염화비닐과 같은 플라스틱 필름 종류는 강산이나 강염기의 특성을 가진 세척제나 염소와 황이 포함된 유기인제를 포함한 세척제를 사용할 경우 내구성이 급격히 떨어져 파손의 우려가 있을 뿐만 아니라 토양오염의 원인이 되기도 한다. 반면에 인력이 많이 소모되는 손세척방법은 농가에서 쉽게 이용하기가 곤란하다. (중략)

• Korean Journal of Veterinary Pathology
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• v.5 no.2
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• pp.75-78
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• 2001

A dead nine-month-old female hooded crane (Grus monachus) fecund in Chonnam province was examined pathologically, bacteriologically and toxicologically. Pathologically multiple necrotic foci consisting of infiltration of heterophil, lymphocytes and macrophages, and exudation of fibrin were observed in liver. Kidney had multiple hemorrhagic foci. Aeromonas hydrophila identified by biochemical properties was isolated. Phosphamidon, a kind of organophosphate, was detected massively in feed content of gizzard. From these results, lethal ingestion of phosphamidon was a causative agent of death. In addition, future study has to be done about correlation between liver necrosis and A. hydrophila infection.