• Journal of Food Hygiene and Safety
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• v.14 no.3
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• pp.249-254
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• 1999

The present study was performed to investigate biodegradation rate of BPMC(2-sec-butylphenyl methyl carbamate) and chlorothalonil. In the biodegradation test of two pesticides by the modified river die-away method from June 17 to August 22, 1998, the biodegradation rate constants and half-life were determined in Nakdong(A) and Kumho River(B). Bio- degradation rate of BPMC was 27% in A sampling point, 40% in B sampling point after 7 days. Biodegradation rate constants and half-life of BPMC were 0.0460 and 15.1 days in A sampling point, 0.0749 and 9.3 days in B sampling point, respectively. Biodegradation rate of chlorothalonil was 100% in A and B sampling points after 7 days. Biodegradation rate constants and half-life of chlorothalonil were 0.1416 and 4.9 hours in A sampling point, 0.1803 and 3.8 hours in B sampling point, respectively. Biodegradation rate of chlorothalonil was faster than that of BPMC. Correlation analysis between biodegradation rate constants of pesticides and water quality(DO, BOD, SS, ABS, $NH_3-N\;and\;NO_3-N$) showed significant correlation with BOD, SS and $NH_3-N$. Furthermore, regression analysis with BOD, SS and $NH_3-N$ as independent variable and biodegradation rate constant as independent variable showed a significant linear equation. These results suggested that BPMC and chlorothalonil were mainly degraded by biodegradation, and the difference in biodegradation of two pesticides was due to difference of water quality.

• Journal of Environmental Science International
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• v.6 no.3
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• pp.285-291
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• 1997

In order to Investigate the adsorption characteristics of organochlorine pesticides chlorothaloul and dicofol with soul colors and re참tons far souls of an orange orchard, the souls were sampled at 3 re삼tons, respectively. among black volcanic, dark brown volcanic, and broom nonvolcanlc sorts. Every so6 has a higher clay proportion (49-75%) In sol tcuture and the organic carbon content and cation ekchange capacity with soil decreased in the following sequence: Black volcanic > Dark brown volcanic > Brown nonvolcanic sorts. Especially those In black volcauc trolls were much higher than others. The retention time, quantitative detection limit, and extractian , efficiencies of chlorothalonil and dicofol were 2.82min, 1.5ng/mL, 93.6% and 3.64min, 4.5ng/mL. 94 2%, repectlvely. The Freundlich constant, Kd, was higher in dicofol compared to chlorothalonil and In the black volcanic souls that have higher organic carbon content and cation Bkchange capacity. The Freundlich constant, 1 In, was In the range of 0.76-0.89 In the black volcanic sorts that have a higher organic matter(16.4-19.8%), whereas It was In the range of 1.02-1.13 In the brown nonvolcanic souls that have a lower organic matter(2.4-3.4%), and so It was considered that 1 In was dependent on the organic matter.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.3-5
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• 2003

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.419-426
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• 2009

This study was conducted to know the biological half-lives and dissipation patterns of fungicides, pyrimethanil, chlorothalonil and tetraconazole in Korean melon under green house condition. The instrument for analyzing pyrimethanil and chlorothalonil was HPLC equipped with UV detector. Initial residue amounts of pyrimethanil were 0.16 mg/kg at recommended rate and 0.28 mg/kg at double recommended rate in Korean melon. The biological half-lives of pyrimethanil were 11.2 days at recommended rate and 10.1 days at double recommended rate in Korean melon. In case of chlorothalonil, initial residue amounts of chlorothalonil were 0.06 mg/kg at recommended and 0.11 mg/kg at double recommended rate in Korean melon. The biological half-lives of chlorothalonil in Korean melon were 3.4 days at recommended rate and 6.6 days at double recommended rate. The instrument for analyzing tetraconazole was GLC equipped with electron capture detector. Initial residue amounts of tetraconazole were 0.14 mg/kg at recommended and 0.22 mg/kg at double recommended rate in Korean melon, respectively. The biological half-lives of tetraconazole were 9.6 days at recommended rate and 18.5 days at double recommended rate in Korean melon.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.165-175
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• 2010

A gas chromatographic (GC) method was developed to determine residues of captan, folpet, captafol, and chlorothalonil, known as broad-spectrum protective fungicides for the official purpose. All the fungicide residues were extracted with acetone containing 3% phosphoric acid from representative samples of five agricultural products which comprised rice, soybean, apple, pepper, and cabbage. The extract was diluted with saline, and dichloromethane partition was followed to recover the fungicides from the aqueous phase. Florisil column chromatography was additionally employed for final cleanup of the extracts. The analytes were then determined by gas chromatography using a DB-1 capillary column with electron capture detection. Reproducibility in quantitation was largely enhanced by minimization of adsorption or thermal degradation of analytes during GLC analysis. Mean recoveries generated from each crop sample fortified at two levels in triplicate ranged from 89.0~113.7%. Relative standard deviations (RSD) were all less than 10%, irrespective sample types and fortification levels. As no interference was found in any samples, limit of quantitation (LOQ) was estimated to be 0.008 mg/kg for the analytes except showing higher sensitivity of 0.002 mg/kg for chlorothalonil. GC/Mass spectrometric method using selected-ion monitoring technique was also provided to confirm the suspected residues. The proposed method was reproducible and sensitive enough to determine the residues of captan, folpet, captafol, and chlorothalonil in agricultural commodities for routine analysis.

• The Korean Journal of Pesticide Science
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• v.4 no.4
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• pp.31-34
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• 2000

The contents of hexachlorobenzene (HCB), a hazardous impurity, in chlorothalonil were monitored through 1996 to 2000. The number of samples were 32 from three different sources. The contents determined by GLC/ECD were ranged from 0.0036% to 0.0330% with average content of 0.0219%. All the samples were recorded below 0.05%, which is the regulation standard of HCB in the technical. The total input of HCB in Korean agriculture was calculated to be approximately 77 kg a year.

• The Korean Journal of Food And Nutrition
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• v.14 no.5
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• pp.446-456
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• 2001

This study was carried out for the dietry safely based on the level of pesticide residues In 13 kinds of agricultural products consumed in Kyonggi-Do. Korea. From June to October 2000, sixteen organochlorine pesticides in 397 samples were analyzed by using GC/ECD and GC/MSD. According to the results, endosulfan were detected in 27(7.8%) samples and chlorothalonil were detected in 4(1.0%) samples. Detection ranges of endosulfan were 3.7437∼ 0.0488ppm for lettuce, 2.1902 ∼0.1423ppm for spinach, 2.4909 ∼0.0786ppm for mallow and 3.2333∼0.3997ppm for mustard leaf, respectively Chlorothalonil were 5.8097 for lettuce and 0.8962ppm for spinach. Consequently, six agricutural products were detected more than the maximum residue limits in Korea Endosulfan were detected In 5(1.8%) samples and cholrothalonil were detected in 1(0.3%) sample. Detection rates of endosulfan sulfate(45.9%) of agricultural products were more than $\alpha$-endosulfan(28.5% ) and $\beta$-endosulfan (23.9% ) .

• Korean Journal of Environmental Agriculture
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• v.6 no.2
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• pp.84-93
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• 1987

The water solubilities and vapor pressures of chlorothalonil and Command were measured following the guidelines of the U.S. EPA and OECD. Water solubility of the two compounds is consistent with respective values in the literature. However, the vapor pressures of Chlorothalonil and Command were 5,000 times$(2{\times}10^{-7}\;torr\;at\;25^{\circ}C)$ and 100 times$(<1{\times}10^{-6}\;torr\;at\;45^{\circ}C)$ lower than the literature values, respectively. Courteous use of the vapor pressure values in the handbooks is suggested. With this study, experimental difficulties involved were recognized. Based on the low vapor pressure of Command, the cause of the accidental bleach of non-target plants in the United States might not be attributed to the volatilization of Command, but to the drift during the application of the herbicide. These approaches will be utilized to predict the environmental fate of new chemicals under development, to screen the potential environmental pollutants among chemicals already in use, and to assess measures to minimize the hazards.

• Journal of Food Hygiene and Safety
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• v.34 no.2
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• pp.191-198
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• 2019

This study investigated the residual characteristics of bifenthrin and chlorothalonil in crown daisy and suggested pre-harvest residue limits (PHRLs) based on their dissipation patterns and biological half-lives. The samples for residue analysis were harvested at 0 (3 hr), 1, 3, 5, 7, 9, 11, 13, 15, 18, 22 and 26 days after treatment, and analyzed by $GC/{\mu}-ECD$ and TOF/MS. The limit of quantitation (LOQs) of bifenthrin and chlorothalonil were 0.0046 mg/kg and 0.0007 mg/kg, respectively. Recoveries ranged from $88.67{\pm}7.97%$ and $99.90{\pm}16.03%$, showing that this method is appropriate for the analysis of the pesticide residues in crown daisy. Being well within first order kinetics, the biological half-lives of the pesticide residues in crown daisy were 9.63 days for bifenthrin and 6.54 days for chlorothalonil. The PHRLs of bifenthrin and chlorothalonil were recommended as 11.70 mg/kg and 24.10 mg/kg for 26 days before harvest, respectively.

• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.34-42
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• 2008

In order to know the residual pattern of some pesticides and predict to the degradation period until below MRL, we experimented chlorothalonil, indoxacarb, lufenuron, metalaxyl and methomyl for Chinese cabbage. They were frequently detected pesticides in Chinese cabbage by NAQS (National Agricultural product Quality management Service) monitoring survey. In this experiment, we sprayed those pesticides 10days before harvest and analyzed 0, 1, 2, 3, 5, 7, 10 day samples to establish logical equation and to calculate $DT_{50}0$. During the cultivating period, the residue amount of chlorothalonil was changed from $55.58\;mg\;kg^{-1}$ (0 day) to $20.08\;mg\;kg^{-1}$ (10 day), $DT_{50}$ was 7.45 days, indoxacarb was $7.85\;mg\;kg^{-1}$ (0 day) to $1.46\;mg\;kg^{-1}$ (10 day), and 4.2 days, lufenuron was $1.57\;mg\;kg^{-1}$ (0 day) to $0.49\;mg\;kg^{-1}$ (10 day), and 5.85 days, metalaxyl was $8.12\;mg\;kg^{-1}$ (0 day) to $0.10\;mg\;kg^{-1}$ (10 day), and 175 days, and methomyl was $11.51\;mg\;kg^{-1}$ (0 day) to $0.80\;mg\;kg^{-1}$ (10 day), and 2.42 days at single dose application, respectively. The $DT_{50}$ of double amount in those pesticides were 9.05 days in chlorothatonil, 7.09 days in indoxacarb, 8.82 days in lufenuron, 3.32 days in metalaxyl, and 2.72 days in methomyl, respectively.