• The Korean Journal of Pesticide Science
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• v.17 no.2
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• pp.94-106
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• 2013

The proficiency testing for the residue laboratories of pesticide registration was conducted in order to improve the reliability and the ability for pesticide residue analysis. On October 2011 the testing was carried out using the soil collected and kept as the moistened state for five years, which is expected to very low residue levels of pesticides. The soil was fortified with chlorpyrifos, metolachlor and procymidone in a manner similar to prepare soil sample for indoor soil degradation test, and then sub-samples were prepared for the distribution to participants. Some of them were randomly selected for confirm of homogeneity and to ensure the stability of samples at room temperature. Samples were consisted of two soil treated as different levels, one of which was used to the assesment and another used to confirm. In addition, provide three standard solutions, respectively concentration of 10 mg/L, and untreated soil. Forty seven institutions submitted results. The medians of results were used as the assigned values for pesticide residues. Fitness for purpose standard deviation of proficiency test was calculated by applying 20% RSD as the coefficient of variation allowed in the soil residue test. Z-score was applied for evaluation of individual pesticides, and the average of the absolute value of the Z-score for the overall assessment of pesticides. Laboratories evaluated the absolute value of the Z-score less than 2 to fit the case of chlorpyrifos and procymidone were 44, metolachlor 40.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.247-257
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• 2014

Assessment for operator's dermal and inhalation exposure to acetamiprid during cultivation of water melon in greenhouse was carried out. For dermal exposure measurement, whole body dosimetry (WBD) was performed as the first trial in Korea. WBD consists of cotton/polyester outer clothes and cotton inner clothes. Hand exposure was measured by washing of nitrile gloves and hands while head exposure was monitored by face/neck wipe technique. Inhalation exposure was monitored with personal air sampling pumps and IOM sampler (glass fiber filter). Analytical limit of quantitation was 2.5 ng/mL. Good reproducibility (C.V < 8.7%), linearity ($R^2$ > 0.99) and recovery (70~119%) were obtained. Field recovery of acetamiprid was 77~95%. During mixing/loading, hand exposure of acetamiprid was about 10 times ($229.7{\mu}g$) more than that of application case ($20.9{\mu}g$). During application, total dermal exposure was $1207.4{\mu}g$. Exposure of lower legs was $1132.1{\mu}g$, which is 93.8% of the total dermal exposure. Inhalation exposure during mixing/loading and application was not detected. Margin of safety (MOS) was calculated for risk assessment using male Korean average body weight (70 kg) and acceptable operator exposure level ($124{\mu}g/kg/day$) to give 140, suggesting that health risk of operator during treatment of acetamiprid for water melon in greenhouse could be safe.

• The Korean Journal of Pesticide Science
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• v.5 no.4
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• pp.62-67
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• 2001

In order to investigate the harmful effects of Fusarium, producing mycotoxins, contaminated cereals, two months feeding study was carried out in SPF-ICR mice. Mice diets were incorporated with 30% Fusarium infected wheat, nepal barley or barley. The wheat was processed to flour. The nepal barley and barley were polished by 68% and 58%, respectively. The cereal incorporating amount in mice diet were 0, 10, 30 and 50% for each processed cereal. Five week-old mice were fed with the prepared diet for 2 months. The effects of Fusarium contaminated cereals on the mice were observed after the feeding. The rates of body weight gain, diet and water consumption were not changed. There were no significant changes on hematology, blood biochemistry, gross and histopathological evaluation, organ weights in all treatment groups. These results suggest that the diets have no deleterious effects to ICR mice.

• The Korean Journal of Pesticide Science
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• v.10 no.1
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• pp.28-35
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• 2006

This study was conducted to optimize formulation factors of a self-dispersible floating granule of flucetoaulfuron that can be used at a low application volume (5 kg $ha^{-1}$). SPA and xanthan gum were selected as a binder because blending of them showed good granulation and floatation. Potassium chloride selected as a filler also showed good granulation, floatation and disintegration properties. Among wetters and dispersants, Surfynol 440 gave the best dispersibility The optimum granule size was determined to be 1.0 mm considering floating time and dispersibility. Flucetosulfuron was mixed with the blend of SPA and xanthan gum, potassium chloride, and Surfynol 440 and formulated as a floating self-dispersible granule at 1.0 mm in diameter. Indoor and outdoor field experiments showed that the floating granule of flucetosulfuron performed well, covering long range from the application spot up to 15 m in weed control. Therefore, this floating technology may be used for laborsaving herbicide formulation development and help to reduce workloads for herbicide application.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.203-208
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• 2009

In order to elucidate the effect of spreader-stickers on the rainfastness of dithianon and chlorothalonil wettable powders, and to estimate the possibility of suggesting good new formulations, the fungicide residues on the leaf surface of hot pepper was assessed and compared after the drop-wise applications of fungicide suspensions containing spreader-sticker on leaf surface followed by artificial raining. Three commercial spreader-stickers, which were Cover, Reitron and Silwet, not only made the rainfastness of dithianon wettable powders worse on hot pepper leaf, but increasing their concentrations also accelerated it further. On the other hand, to chlorothalonil wettable powder, Reitron showed the 3-fold improvement of rainfastness. But, for the rest, there was no improvement as well. The effect of N-octylpyrrolidone (NOP) on rainfastness of both fungicides was excellent. Soybean oil formulations containing leaf-penetrable nonionic surfactant, which was either polyoxyethylene monotridecyl ether or polyoxyethylene monolauryl ether, improved dithianon rainfastness, but the ones containing conventional emulsifiers did not.

• Korean Journal of Environmental Agriculture
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• v.11 no.1
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• pp.59-66
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• 1992

An enzyme immunoassay(EIA) was developed for the analysis of insecticide endosulfan and its degradation products. The sensitivity and specificity of the antibody produced were examined. Optimal conditions in the ELISA system for residue analysis were also discussed. A mixed suspension of endosulfan-hemocyanin conjugate(ES-KLH) 1.1 mg/ml and Freund's adjuvant was injected subcutaneously to white rabbits and then collected antisera were tested for titers by indirect ELISA(1/24,000). Because of difficulties in the synthesis of endosulfan peroxidase conjugate, amine derivative of endosulfan-diol was synthesized and it showed 40% of conjugate yields(2mg/ml of conjugate). the highest sensitivity obtained enzyme-conjugate was a concentration of 200ng/ml. The detection limit of endosulfan in ELISA system was 5 ppb on the standard curve. In application of ELISA for residue analysis, the recoveries were really 100% both in the spiked soil and apple sample regardless of endosulfan concentration treated. On the other hand, chlorinated hydrocarbons of similar structure with endosulfan showed low cross-reactivity$(2.2%{\sim}29.2%).$

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.99-99
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• 2011

최근 건강에 대한 관심이 높아지면서 천연 기능물질을 이용한 고기능 및 고부가가치 상품개발이 여러 산업분야에서 일반화되는 추세이다. 대표적으로 마이크로캡슐은 원하는 기능을 발휘할 수 있는 기능성 물질을 다양한 방법으로 다양한 제품에 부여함으로써, 기능성 물질을 오랜 기간 동안 외부로 방출하거나 외부의 환경으로부터 보호하는 수단으로 각광받고 있다. 이러한 마이크로캡슐은 의약분야 제초제, 멸충제, 곰팡이 방지제, 살균제로 적용되는 농약분야, 식품 분야, 화장품 분야 등의 전반에 걸쳐 응용 및 연구가 활발히 이루어지고 있다. 이에 본 연구에서는 다양한 나노 합성기술과 유/무기 하이브리드를 이용해 서방화 관련 기술을 개발하여 보습성, 항균, 노화방지, 외부 유해물질로부터의 피부보호 특성을 가진 인체 친화형 복합기능성 섬유 가공조제를 개발하여 다양한 섬유소재에 적용하고자 하며, 궁극적으로 기존 선진국 제품의 기능을 뛰어넘는 원천기술, 즉 새로운 가공제 합성과 응용성, 그 성능평가와 동시에 최적의 처리기술을 개발함으로써 섬유제품의 부가가치를 높이는 계기를 마련하고자 한다. 본 연구에서는 나노미터 직경을 갖는 침상형의 주형(hydroxyapatite)을 이용하여 중공 나노구조체를 제조 한 후 이에 천연고분자를 혼합하여 초음파처리 후 유/무기 하이브리드 기술을 이용한 서방성 가공제를 합성하였다. 중공의 나노구조체 확인은 투과전자현미경(TEM)을 이용하였으며, 주형의 나노구조체는 주사전자현미경(FE-SEM)으로 확인하였다. 이상의 결과를 통해 본 연구에서 제안한 방법이 나노구조체의 새로운 합성방법으로써 가능성을 확인할 수 있었다.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.389-400
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• 2011

A high-performance liquid chromatographic (HPLC) method was developed to determine residues of phenothrin and silafluofen, known as synthetic pyrethroids, in agricultural commodities. Insecticide residues were extracted with acetone from representative samples of four crops which comprised rice, apple, pepper and cabbage. The extract was purified serially by liquid-liquid partition and Florisil column chromatography. For rice and pepper samples, acetonitrile/n-hexane partition was additionally adopted to remove nonpolar interferences. Reversed phase HPLC using an octadecylsilyl column was successfully applied to separate two phenothrin isomers and silafluofen from sample co-extractives. Intact parent compounds were sensitively detected by ultraviolet absorption at 226 nm. Recovery experiment at the quantitation limit validated that the proposed method could apparently determine phenothrin and silafluofen residues at 0.02 and 0.01 mg/kg, respectively. Mean recoveries of phenothrin and silafluofen from four crop samples fortified at three levels in triplicate were in the range of 82.4~109.8% and 83.7~109.8%, respectively. Relative standard deviations of the analytical method were all less than 10%, irrespective of crop types and spiking levels. A selected-ion monitoring (SIM) LC/mass spectrometry (MS) with electrospray ionization was provided to confirm the suspected residue of phenothrin, even though no sufficient ionization of silafluofen was obtained. Both phenothrin and silafluofen could be successfully confirmed by gas chromatography/MS SIM with electron impact at 70 eV. The proposed method is sensitive, repeatable and rapid enough to apply to officially routine inspection of agricultural products.

• The Korean Journal of Pesticide Science
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• v.6 no.4
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• pp.287-292
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• 2002

To establish effective and safe control method against Phytophthora root rot caused by Phytophthora capsici on tomato in hydroponic culture, three pesticides, oxadixyl copper hydroxide 8% WP, metalaxyl copper oxychloride 15% WP, and dimethomorph. dithianon 38% WP at 4 concentration levels were tested on potato dextrose agar medium inoculated with Phytophthora capsici. All pesticides inhibited mycelial growth, but two pesticides of them, metalaxyl copper oxychloride WP and dimethomorph. dithianon WP, were selected as effective pesticides for the efficacy test in a hydroponic culture. Forty days after transplanting of tomato seedlings, 4 ml of sporangia of P. capsici (about 25 sporangi/ml) per plot was inoculated around tomato plant root, and then 5 days after inoculation, the pesticides diluted at 5,000 times were drenched 1, 2 or 3 times per plot on the culture cube at 15 days interval. Fifteen days after drenching, tomato fruits and hydroponic culture solution were sampled for the analysis of pesticide residues. Dimethomorph was detected 0.001 and 0.003 mg/kg in tomato of the plots sprayed 2 and 3 times with dimethomorph dithianon WP of which detection levels were far below compared with 1.0 mg/kg of the Korean MRL of dimethomorph on tomato. Incidences of Phytophthora root rot were $30.5{\sim}50%$ in the plots drenched at 1 or 2 times with metalaxyl.copper oxychloride WP, and $16.7{\sim}25%$ in the plots treated with dimethomorph dithianon WP. However, there was no incidence of Phytophthora root rot in the plots treated at 3 times with both of pesticides, showing no phytotoxic effect. Based on the results, the drenching of these pesticides on the culture cube could be recommended as a very safe and effective control method for Phytophthora root rot in tomato.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.83-92
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• 2016

New tree wound-treatment formulations (WTF) were developed in this study. Stimulating effects of plant growth regulating substance on callus formation were evaluated in vivo twig disc culture of Zelkova serrata, Ziziphus jujuba, Pinus densiflora, Ginkgo biloba. and Aesculus turbinata. Based on the evaluation, WTF were prepared with 2,4-D, NAA, and IBA using xanthan gum as an extending agent. WTF were pasted on $2{\times}10cm$ artificial wound on the stem and the effects were evaluated 12 weeks later with the thickness of new callus-tissues. The effects varied with tree species and the growth regulators. In Z. serrata and A. turbinata, 2 mg/L of 2,4-D was the best WTF. In P. koraiensis and G. biloba, 8 mg/L of NAA and 1 mg/L of IBA were the best, respectively. Callus formation was quite lower in G. biloba compared to other species. Stimulating effect of thiophanate-methyl paste was excellent only in Z. serrata and lower than certain WTF in other species. Vaseline, which was used generally as an WTF, remained longer on the wound and causing decay. From the results, it could be recommended that 2,4-D, NAA and IBA were the best WTF for Z. serrata/A. turbinata, P. koraiensis and G. biloba, respectively.