• Journal of Food Hygiene and Safety
• /
• v.37 no.4
• /
• pp.238-248
• /
• 2022

This study was conducted to evaluate the safety of 208 types of residue pesticides on 150 dried agricultural products in Ulsan. The pesticide residues were detected using GC-MS/MS, LC-MS/MS, GC/ECD, GC/NPD, and LC/PDA. The detection rate was 19.3% (29 of 150 samples), and 28 types of pesticides were detected. Two of the 29 pesticide residues exceeded the maximum residue limit (MRL). Difenoconazole was detected in Ulleungdo aster, and chlorothalonil and chlorpyrifos were detected in chili pepper leaves. In the vegetable group, the frequency of pesticide residues was found to be the highest in dried leafy vegetables, followed by dried fruiting vegetables other than cucurbit vegetables, and then dried stalk and stem vegetables. The pesticide types detected in the commercial dried agricultural products were fungicide (60%), insecticide (23.8%), and acaricide (16.3%). In the validation study, the values of limit of detection (LOD), limit of quantitation (LOQ), coefficient of determination (R²), and recovery rate were in the range of 0.0001-0.0409 mg/kg, 0.0003-0.1241 mg/kg, 0.994-0.999, and 81.58-116.79%, respectively. The ratio of estimated daily intake (EDI)/acceptable daily intake (ADI) was 0.00002-0.31395%.

• Korean Journal of Environmental Agriculture
• /
• v.28 no.3
• /
• pp.281-288
• /
• 2009

The strobilurin fungicides, azoxystrobin and kresoxim-methyl, were investigated to know the biological half-lives and dissipation patterns in Korean melon under plastic film house condition. Used pesticides for field application were 20% azoxystrobin of suspension concentrate and 47% kresoxim-methyl of water dispersible granule. Two pesticides were sprayed at recommended and double dose rate. Pesticide residues in Korean melon were analyzed until 14 days after application. The azoxystrobin was analyzed by HPLC equipped with UV detector after cleanup with florisil glass column. Initial residue concentrations of azoxystrobin in Korean melon at recommended and double dose rate were 0.09 mg/kg and 0.14 mg/kg, respectively. Those were less than 0.2 mg/kg maximum residue limit of Korean melon established by KFDA. The biological half-lives of azoxystrobin in Korean melon were 4.7 days at recommended dose rate and 7.8 days at double dose rate. Initial concentrations of kresoxim-methyl which was analyzed by GLC-ECD in Korean melon at recommended and double dose rate were 0.10 mg/kg and 0.23 mg/kg, respectively. Those were less than 1.0 mg/kg, MRL. The biological half-lives of kresoxim-methyl in Korean melon were 4.1 days at recommended dose rate and 4.8 days at double dose rate. The residue amounts of both pesticide was lower than MRL and biological half-lives were not so long. Because the weight of Korean melon under plastic film house condition was fast increased during cultivation.

• The Korean Journal of Pesticide Science
• /
• v.9 no.3
• /
• pp.237-242
• /
• 2005

This experiment was carried out to develop the fast and simple method for pesticide residue analysis by using solvent free solid injector (SFSI) and to validate the efficiency of the method developed for the residue analysis of the endocrine disruptor-like pesticides such as endosulfan, metribuzin, trifluralin and vinclozolin. The samples after freeze drying were sealed in glass capillary tubes and then introduced into the heated injector of gas chromatogaphy. The required pre-heating times were 1 min for endosulfan and trifluralin, 5 min for vinclozolin, and 10 min for metribuzin. The detection limits of endosulfan in chinese cabbages, metribuzin in lettuces, trifluralin in spinachs and vinclozolin in hot peppers were 0.05, 0.1, 0.05 and 0.05 ng, respectively and their recoveries were ranged from 74%, $98{\sim}107%$, $86{\sim}95%$ and $94{\sim}95%$, respectively. The detected level of metribuzine residue in field lettuce samples by using the SFSI was 0.6 ng/mg.

• Food Science and Preservation
• /
• v.21 no.1
• /
• pp.69-74
• /
• 2014

We tested for residual pesticide levels in school foodservice agricultural products in Seoul, Korea from 2010 to 2012. A total of 316 samples of 23 different types of agricultural products were analyzed via gas chromatography-nitrogen phosphate detector (GC-NPD), an electron capture detector (GC-${\mu}ECD$), a mass spectrometry detector (GC-MSD), and a high performance liquid chromatography-ultraviolet detector (HPLC-UV). We used multi-analysis methods to analyze 185 different pesticide types. Among the selected agricultural products, residual pesticides were detected in 26 samples (8.2%), of which 6 samples (1.9%) exceeded the Korea Maximum Residue limits (MRLs). We detected pesticide residue in more than 65% of the Chwinamul, while 6 among 9 analyzed samples contained pesticide residue, and 1 sample exceeded the Korea MRLs. Among the 185 kinds of pesticides that we have tested, 18 were detected, while 7 of them were detected more than twice. Data obtained were then used for estimating the potential health risks associated with the exposures to these pesticides. The most critical commodity is carbofuran in the perilla leaves, which has contributed 3.8% to the hazard index (HI). These results showed that the detected pesticides could not be considered as a serious public health problem. Nevertheless, constant supervision is recommended.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.54 no.3
• /
• pp.1-9
• /
• 2012

As topographic characteristics of Korea where 64 % of the national land area is forest and only 17 % is being used as farmland, remediation of farmland contaminated by heavy metals is a considerably important issue. In this study, as an alternative of practically and effectively remediating farmland which was abandoned as its crop plants exceeded maximum residue limit of heavy metals due to mining impact, applicability of stabilization method was examined through the pilot-scale field experiment. Three plots ($L{\times}W{\times}D=3m{\times}2m{\times}0.3m$) were installed at the selected farmland and in plot 1, only soil of the selected farmland was applied, in pilot 2, soil of the selected farmland plus 3 % limestone (w/w) was applied and in pilot 3, soil of the selected farmland plus 3 % limestone was applied and then uncontaminated soil was covered thereon (0.3 m). After that, seeds of radish, Korean cabbage and soybean of which characteristics of edible portions are different were sowed on each plot and cultivated. Afterwards, at a proper harvesting time (app. 80 days later), crop plants and soil were collected and phytoavailability (0.11 M HOAc extractable) of heavy metals in soil and accumulated concentration of heavy metal in edible portion of crop plants were examined. As a result, it was revealed that phytoavailability of heavy metals in soil added with limestone (plot 2) was clearly reduced compared with plot 1 (untreated) and owing to this treatment, accumulated concentration of heavy metals in edible portion of crops was also clearly reduced compared with plot 1. While radish cultivated in plot 1 had exceeded maximum residue limit of agricultural products, in particular, plot 2 using limestone had shown concentration lower than maximum residue limit and this plot had shown little difference with 3 plot where crop was cultivated in uncontaminated soil cover. Therefore, it was considered that for abandoned farmland like the selected farmland, reducing mobility and phytoavailability of heavy metals and reducing crop uptake through stabilization method would be an effective and practical alternative for producing safe agricultural products on a sustained basis.

• Analytical Science and Technology
• /
• v.21 no.6
• /
• pp.518-525
• /
• 2008

Mandipropamid is a new mandelamide-type fungicide to control foliar Oomycete pathogens in some vegetables. An analytical method was developed to determine mandipropamid residues in agricultural commodities using high-performance liquid chromatography (HPLC) and liquid chromatography/mass spectrometry (LC/MS). Mandipropamid was extracted with methanol from grape, tomato, green pepper, Chinese cabbage and potato samples. The extract was diluted with saturated sodium chloride solution and distilled water, and dichloromethane partition was followed to recover the mandipropamid from the aqueous phase. Florisil column chromatography was employed to further remove interfering co-extractives prior to HPLC analysis. Reverse-phased HPLC was successfully applied to determine mandipropamid in sample extracts with the detection at its ${\lambda}_{max}$ (223 nm). Overall recoveries of mandipropamid from fortified samples averaged $99.8{\pm}1.7$ (n=6), $89.3{\pm}5.3$ (n=6), $98.7{\pm}2.2$ (n=6), $99.7{\pm}6.8$ (n=6) and $91.1{\pm}3.1$ (n=6) for grape, tomato, green pepper, Chinese cabbage and potato, respectively. Limit of quantification of the method was 0.02~0.04 mg/kg for all samples. A LC/mass spectrometry with selected-ion monitoring was also provided to confirm the suspected residue. The proposed method was reproducible and sensitive enough to determine the terminal residue of mandipropamid in agricultural commodities.

• Korean Journal of Environmental Agriculture
• /
• v.18 no.4
• /
• pp.349-354
• /
• 1999

This study was conducted to propose residue limits of organophosphorus pesticides in functional foods produced from peels of citrus fruits. For these, not only reduction factors of pesticides in cooking and processing were estimated, but factors needed in order to produce residue limits were identified and their application method was devised. The results were as follows: (1) reduction factors appeared as 0.09-1.60 by different processings of various foods, (2) residue limits of pesticides on dietary fiber and bioflavonoid products could be computed from maximum residue limit of pesticides on the raw agricultural produce, reduction factors, and the anticipated amount of consumption of the functional foods. (3) residue limits of 18 organophosphorus pesticides were proposed in the range of 0.01-3.0mg/Kg on the dietary fiber product and 0.1-80mg/Kg on the bioflavonoid product from citrus fruit peels.

• Korean Journal of Environmental Agriculture
• /
• v.31 no.1
• /
• pp.45-51
• /
• 2012

BACKGROUND: This study was carried out to establish pre-harvest residue limit of fungicides pyrimethanil and trifloxystrobin in persimmon, based on dissipation and biological half-lives of two fungicides residue. METHODS AND RESULTS: Both pyrimethanil and trifloxystrobin were extracted with acetonitrile, clean-up with $NH_2$ SPE cartridge and residue were analyzed by HPLC/DAD. Limit of Detection was 0.01 mg/kg. Average recovery were $81{\pm}1.62%$, $98{\pm}1.58%$ of pyrimethanil, and $91{\pm}2.94%$, $98{\pm}1.25%$ of trifloxystrobin at fortification levels at 0.1 and 0.5 mg/kg, respectively. CONCLUSION: The biological half-lives of pyrimethanil were 15.6 and 11.6 days at sprayed with recommended and double dosage, respectively. The biological half-lives of trifloxystrobin were 10.4 and 10.3 days at sprayed with recommended and double dosage, respectively. The pre-harvest residue limit of pyrimethanil and trifloxystrobin were recommended as 2.69 and 0.83 mg/kg for 10 days before harvest, respectively.

• Plant Resources
• /
• v.8 no.2
• /
• pp.116-121
• /
• 2005

Compositae plants are known to contain biologically active substances that are allelopathic to agricultural crops as well as weed species. Aqueous or methanol extracts and plant residues from leaves of Xanthium occidentale were assayed against alfalfa (Medicago sativa) to determine its allelopathic effects, and the results showed that the extracts applied onto filter paper significantly inhibited seed germination as well as root growth of alfalfa. Aqueous leaf extracts of $40g\;L^{-1}$ were completely inhibitory on root growth of alfalfa, while root growths of barley (Hordeum vulgare L.) and soybean (Glycine max L.) were less sensitive. Leaf residue incorporation at $100g\;kg^{-1}$ into soil on seedling growth of barnyard grass (Echinochloa crus-galli Beauv. var. oryzicola Ohwi) inhibited both shoot and root fresh weights of barnyard grass by 94 and $96\%$, respectively. Methanol extracts from BuOn and EtOAc fractions of X. occidentale reduced alfalfa root growth more than did those from hexane and water fractions. The results based on bioassay of extracts and residues show that X. occidentale had potent an allelopathic activity against other plant species.

• The Korean Journal of Pesticide Science
• /
• v.17 no.4
• /
• pp.249-255
• /
• 2013

The objective of this study was to investigate the exposure assessment of Korean consumers to edifenphos and tricyclazole in cattle product fed the rice straw, using a probabilistic approach. We used tricyclazole and edifenphos residue data in rice straw reported by National Academy of Agricultural Science (NAAS) for the 1998, 1999, 2001 and 2010 monitoring study and National Agricultural Products Quality Management Service (NAQS) for 2009 monitoring study. The mean exposures of edifenphos and tricyclazole for all of Korean consumers were 0.027% and 0.0006% of ADI and $99%^{th}$ percentile exposures were 0.034% and 0.0007% of ADI respectively. The group of 1~6 years old consumers has the lowest exposure of edifenphos and tricyclazole. The group of 19~29 years old consumers has the highest exposure of edifenphos and tricyclazole.