• The Korean Journal of Pesticide Science
• /
• v.13 no.1
• /
• pp.39-44
• /
• 2009

This study was conducted to evaluate the actual risk of fipronil on worker honey bees (Apis mellifera L.) through acute contact toxicity test, acute oral toxicity test, toxicity of residues on foliage test, and small scale field test. The $48h-LD_{50s}$ of fipronil SC on honeybee were $0.005{\mu}g$ a.i./bee in acute contact toxicity test and $0.004{\mu}g$ a.i./bee in acute oral toxicity test, respectively. In toxicity of residues on foliage test, fipronil showed over 90% of mortality during 28days after treatment at recommended application rate. The $DT_{50}$ of dislodgeable foliar residue was 9 days. Finally, In small scale field test, fipronil showed similar toxicity in the residues on foliage test. It was concluded that fipronil has very high acute toxicity and long residual toxicity to honeybee. Therefore, fipronil is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area. To protect honeybee and wild pollinators from outdoor use of fipronil, ultimately it should need to limit for only indoor use to prevent pollinators from unintentionally exposure of fipronil.

• The Korean Journal of Pesticide Science
• /
• v.16 no.3
• /
• pp.202-208
• /
• 2012

A high-performance liquid chromatographic (HPLC) method was developed to determine residues of cyromazine, a triazine insecticide, in agricultural commodities. Cyromazine was extracted with 90% aqueous methanol from representative crops which comprised brown rice, oyster mushroom, oriental melon, watermelon, and Chinese cabbage. Following to evaporation of methanol in the extract, the aqueous concentrate was acidified to form the protonated cyromazine. Dichloromethane partition was then applied to remove nonpolar co-extractives in the aqueous phase. Strong cation-exchange chromatography using Dowex 50W-X4 resin was employed for final purification of the extract. Cyromazine was successfully separated on a Zorbax SB-Aq $C_{18}$ column showing high retention for polar compounds. Cyromazine was sensitively quantitated by ultraviolet absorption at 214 nm. Limit of quantitation (LOQ) of the method was 0.04 mg/kg irrespective of sample types. Each crops were fortified at 3 different concentrations of cyromazine for recovery test. Mean recoveries from samples fortified at LOQ~2.0 mg/kg in triplicate ranged 80.2~103.3% in five agricultural commodities. Relative standard deviations in recoveries were all less than 6%. A selected-ion monitoring LC/MS method with electrospray ionization in positive-ion mode was also provided to confirm the suspected residue. The proposed method was reproducible and sensitive enough to routinely determine and inspect the residue of cyromazine in agricultural commodities.

• The Korean Journal of Pesticide Science
• /
• v.8 no.2
• /
• pp.95-102
• /
• 2004

The present study was conducted to test and evaluate estrogenic effect of 17 pesticides including benomy1 and carbaryl, being suspected as endocrine disrupting chemicals. For estrogenic effect examination, luciferase assay were achieved with human ovarian cancer cell, BG1Luc4E2. Estrogenic effects of cypermethrin, dicofol, endosulfan, esfenvalerate, and fenvalerate were observed at the concentration of $10^{-5}$ M by estrogen receptor binding assay. Relative luciferase potency and relative luciferase effects compared with $10^{-10}$ M 17 $\beta$-estradiol were $10^{-5}$, 56% for dicofol, and $10^{-5}$, 72% for endosulfan, respectively. Estimated maximum daily intake for pesticides was calculated from maximum residue limit of agricultural commodity and food consumption was 1.2298 mg/person. Theoretically calculated blood estrogen level from dietary intake for pesticides based on MRL in Korea, 3.075 ng/L was equivalent to 15% of estrogen concentration in normal blood, but practical monitoring data, 0.01938 ng/L was equal to 0.09693% of estrogen concentration in normal blood.

• The Korean Journal of Pesticide Science
• /
• v.5 no.2
• /
• pp.1-12
• /
• 2001

A competitive indirect enzyme-linked immunosorbent assay (ci ELISA) for the organophosphorus insecticide acephate, O,S-dimethyl acetylphosphoramidothioate, was developed using a polyclonal antibody. Three different haptens mimicking the analyze and containing hexanoic acid moiety as a linker were synthesized, and then conjugated with the carrier proteins bovine serum albumin and keyhole limpet hemocyanin by the N-hydroxysuccinimide active ester method. Polyclonal antibodies raised against hapten-KLH conjugates in rabbits and the hapten-BSA conjugates as coating antigens were screened and selected for the assay in the homologous and/or heterologous ELISA system. The effects of various assay conditions, including blocking reagents, detergent content, organic solvents, pH, and preincubation of tile mixture of the polyclonal antibody and the analyze on the sensitivity were evaluated. The $IC_{50}$ value of acephate of 110 ng/mL was obtained in an optimized heterologous system using hapten-3-BSA as a coating antigen and a polyclonal antibody 8377, showing the detection range of 10-1000 ng/mL and the lowest detection limit of 4 ng/mL. The cross-reactivities of the structurally related insecticides, including methamidophos were less than 0.02%. These results indicate that the ELISA could be a convenient and alternative tool for monitoring acephate residues in agricultural products and environmental samples.

• The Korean Journal of Pesticide Science
• /
• v.15 no.1
• /
• pp.28-35
• /
• 2011

The investigation of 218 residual pesticides for 19 types of tea (persimmon leaf tea, chrysanthemum tea, green tea, lavender tea, rosemary tea, dandelion leaf tea, puer tea, mulberry leaf tea, hydrangea leaf tea, jasmine tea, nuomixiang tea, buckwheat tea, mugwort tea, lotus leaf tea, oolong tea, longjing tea, rose tea, tiehkwanyin tea and huoguo tea) obtained from markets in Ansan and Suwon was carried out to assess the risk for residual pesticides in tea. The detection rate was 23.1 % (19 samples of total 65 tea samples) and the detected pesticides were 15 pesticides, such as bifenthrin, bromopropylate, chlorpyrifos, cyhalothrin, cypermethrin, chlorfenapyr, dicofol, endosulfan, fenpropathrin, fludioxonil, fenvalerate, iprobenfos, isoprothiolane, tetradifon and triazophos. The range of concentrations for the detected residual pesticides was 0.01 to 1.24 mg/kg which showed below their maximum residue limits (MRL), but the residual concentration of bifenthrin in a puer tea showed above the legal limit of 0.3 mg/kg. The result of risk assessment of residual pesticides for the detected 15 samples showed that EDI (estimated daily intake) of the pesticides detected ranged 0.0001~0.0844% of their ADI (acceptable daily intake).

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.8
• /
• pp.1231-1235
• /
• 2010

The method for residue analysis of four sulfonylurea pesticides, rimsulfuron, ethametsulfuron-methyl, tribenuron-methyl and chlorimuron-ethyl was examined and analyzed by HPLC with ODS column ($250\;mm{\times}4.6\;mm$, $5\;{\mu}m$ diameter particle size) which was maintained at $35^{\circ}C$. Mobile phase consisted of solvent A (20 mM $KH_2PO_4$, pH 2.5) and solvent B (acetonitrile). Isocratic elution of the column with 45% solvent A and 55% solvent B at a flow rate of 1 mL/min resulted in retention times of 5.92, 6.54, 9.28, and 14.35 min for rimsulfuron, ethametsulfuron-methyl, tribenuron-methyl, and chlorimuron-ethyl, respectively. All injection volumes were $20\;{\mu}L$. The limit of quantitation was 0.02, 0.01, 0.001, and 0.004 mg/kg for rimsulfuron, ethametsulfuron-methyl, tribenuron-methyl, and chlorimuron-ethyl, respectively. Recovery rate test was performed with three farm products, rice, apple and soybean. Four sulfonylurea pesticides were spiked at concentrations of 0.05, 0.1 and 0.5 mg/kg. The recovery rates were ranged from 86.12% to 116.26% and the standard deviations of all experiments were within 10%.

• Korean Journal of Food Science and Technology
• /
• v.45 no.4
• /
• pp.391-402
• /
• 2013

Pesticide residues in agricultural products in Korea were evaluated to create a data base to inform food policy. Pesticide residues were investigated in 17 commodities collected from 9 provinces in 2012. Our analytical method of multiresidue analysis, involved the analysis of individual recovery, linearity, limit of detection, and limit of quantitation of 60 pesticides in six matrices. The pesticides, including acetamiprid and forchlorofenuron, were evaluated in 358 agricultural samples by liquid chromatography/tandem mass spectrometry. Twenty three pesticides were detected from 67 samples. The results showed that the ratio of estimated daily intake to acceptable daily intake was 0.00009-0.0861% by the intake assessment, which means that residual pesticides in agricultural products in Korea are properly controlled.

• Analytical Science and Technology
• /
• v.25 no.6
• /
• pp.364-369
• /
• 2012

Isotianil is a novel fungicide which induces systemic acquired resistance in plants. It has excellent preventive effects as low dosages against rice blast which is one of the most serious diseases in rice. The Maximum Residue Limit (MRL) of Isotianil in republic of korea was set to 0.1 mg/kg in rice, so it is necessary to determine levels of Isotianil residues in agricultural commodities for controlling food safety. Therefore, The purpose of this study was to develop analytical method for the determination of isotiical residues in agricultural commodities using GC-NPD/MSD. Isotianil was extracted with acetonitrile from apple, chinese cabbage, hulled rice, mandarin, pepper, and soybean. The extract was diluted with saline water, and then dichloromethane partition was followed to recover this fungcide from the aqueous phase. A solid phase extraction with Florisil cartridge was additionally employed for final clean up. Isotianil was analyzed and quantitated by GC-NPD and confirmed by GC-MSD. Average recovery of Isotianil ranged from 70.0 to 103.9% in six representative agricultural commodities with relative standard deviations less than 10%, and limit of quantification (LOQ) was 0.05 mg/kg.

• Journal of Applied Biological Chemistry
• /
• v.59 no.4
• /
• pp.331-336
• /
• 2016

Analytical methods for methiozolin in soil, water and turfgrass were established and dissipation patterns of methiozolin in soil and turfgrass were elucidated. Analysis was done using a high performance liquid chromatography with an ultra violet detector at the wavelength of 280 nm after extraction with acetone, liquid-liquid partition with dichloromethane, and a solid phase extraction purification. Limit of determination and Limit of quantitation were 1.0, 0.5, 1.0 ng, and 0.001, 0.1, 0.01 mg/kg for water, turfgrass, and soil, respectively. Recovery rates of methiozolin from soil, water, and turfgrass were ranged 87.5~111.3, 92.8~97.4, and 78.2~98.5 %, respectively. The turfgrass and soil samples were collected at 0, 1, 4, 7, 14, 30, 45, and 60 after spray on green area in golf course. Residues of methiozlolin were not translocated to lower soil layer but detected only in turfgrasses and root area of turfgrass. Half-lives of methiozolin in turfgrass were 10.7 days and 8.8 days in soil from root area.

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