• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.575-579
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• 2007

This study was performed to acquire scientific data for establishing the maximum residue limits (MRLs) of pesticides in Korean red ginseng and its extract. Pesticides (azoxystrobin, fenhexamid, cyprodinil) were applied to a cultivated field of ginseng, and the fresh ginseng was harvested and processed to make Korean red ginseng and its extract. The reduction rates of the residue pesticides were calculated by determining the pesticide contents in each stage of ginseng processing. The residue levels in fresh ginseng were 0.12 ppm for azoxystrobin, 0.19 ppm for fenhexamid, and 1.78 ppm for cyprodinil. The residue levels in Korean red ginseng were 0.24, 0.54, and 1.49 ppm, and in the extract 0.81, 1.93, and 3.66 ppm for azoxystrobin, fenhexamid, and cyprodinil, respectively. The steaming and processing of fresh ginseng increased azoxystrobin and fenhexamid residues, but cyprodinil was reduced. The reduction rates (dry basis) of azoxystrobin, fenhexamid, and cyprodinil were 0.66, 0.94, and 0.28 for Korean red ginseng, and 3.25, 4.94, and 1.01 for the extract, respectively.

• The Korean Journal of Pesticide Science
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• v.19 no.4
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• pp.361-369
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• 2015

This study investigated residual characteristics of bistrifluron and fluopicolide in Korean cabbage, and suggested the pre-harvest residue limits (PHRLs) based on their dissipation patterns and biological half-lives. The pesticides were sprayed on Korean cabbage in two different region under greenhouse conditions at the recommended dose, respectively. The samples for residue analysis were harvested at 0 (2 hr), 1, 2, 4, 6, 8 and 10 days after treatment, and analyzed by HPLC after clean-up with Florisil SPE. The limit of quantification (LOQ) was $0.03mg\;kg^{-1}$ for bistrifluron and fluopicolide, and the recoveries ranged from 87.2-110.6% with below 5% of RSD. The biological half-lives of field I and field II were 3.9 and 4.2 days for bistrifluron and 4.9 and 4.2 days for fluopicolide, respectively. The PHRL of bistrifluron and fluopicolide were recommended as 3.83 and $3.23mg\;kg^{-1}$ for 10 days before harvest, respectively.

• The Korean Journal of Pesticide Science
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• v.17 no.2
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• pp.107-116
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• 2013

Polar pesticides like pymetrozine (log $P_{ow}$: -0.18) are known to be difficult to analyze. The analytical method of pymetrozine using hydromatrix included in the official method of KFDA was uncommon and provided ambiguous evidence to confirm both the identity and the quantity. Therefore, precise single residue analytical method was developed in representative crops for using liquid-liquid extraction (LLE). The pymetrozine residue was extracted with methanol from 11 representative crops which comprised apple, blueberry, broccoli, cabbage, cherry, crown daisy, hulled rice, Korean cabbage, potato, rice and watermelon. The extract was purified serially by liquid-liquid extraction (LLE) and silica solid phase extraction (SPE). For rice and hulled rice samples, n-hexane partition was additionally adopted to remove nonpolar interferences, mainly lipids. The residue levels were analyzed by HPLC with DAD, using $C_8$ column. LOQ (limit of quantitation) of pymetroizinie was 1 ng (S/N > 10) and MQL (method quantitation limit) was 0.01 mg/kg. Mean recoveries from 11 crop samples fortified at three levels (MQL, 10 ${\times}$ MQL and 50 ${\times}$ MQL) in triplicate were in the range of 83.1~98.5% with coefficients of variation (CV) of less than 10%, regardless of sample type, which satisfies the criteria of KFDA. The method established in this study could be applied to most of crops as an official and general method for analysis of pymetrozine residue.

• The Korean Journal of Pesticide Science
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• v.17 no.2
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• pp.77-83
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• 2013

This study was performed to investigate pre-harvest residue limit (PHRL) in amaranth, to estimate biological half-life of emamectin benzoate and identify the characteristics of the residue. Pesticides of standard and double appplication rate, were sprayed once on amaranth at 0, 1, 2, 3, 5, 7, 10, 14 days before harvest. Amaranth sample was extracted with acetonitrile and partitioned with dichloromethane, and pesticide residues were determined with LC/MS/MS. The limit of detection of emamectin benzoate was 0.01 mg/kg. Recoveries of emamectin benzoate ($B_{1a}$, $B_{1b}$) at two fortification levels of 0.1 and 0.5 mg/kg, $B_{1a}$ were $93.3{\pm}0.7%$ and $93.2{\pm}7.7%$, $B_{1b}$ were $106.6{\pm}1.9%$ and $80.5{\pm}6.6%$, respectively. The biological half-lives of emamectin benzoate were about 2.0 days at standard application rate and 1.7 days at double application rate, respectively. The PHRL of emamectin benzoate were recommended as 0.84 mg/kg for 10 days before harvest.

• Journal of the Korean Wood Science and Technology
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• v.41 no.1
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• pp.1-11
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• 2013

In this study, we investigated chemical characteristics of solid residues obtained from inorganic acid hydrolysis of hybrid poplar (Populus alba ${\times}$ glandulosa). Different concentration (72, 36, 18%) of sulfuric acid and hydrochloric acid were used for first hydrolysis step and second hydrolysis step were carried out after equally dilution to 4%. Solid residues after consecutive two step hydrolysis were named to RS72 (Residue from Sulfuric acid 72%), RS36, RS18, as well as RC36 (Residue from hydroChloric acid 36%) and RC18, respectively. The yield of RS decreased from 71.2% to 21.4% with increasing sulfuric acid concentration in the first hydrolysis step, whereas that of RC showed little difference (67.0% to 65.0%), irrespective of hydrochloric acid concentration. The lignin content in solid residue was 23.6% for both of RS36 and RS18, 25.6% for RC36 and 27.3% for RC18, respectively. The results of pyrolyzer-GC/MS showed that 24 cellulose derivatives (Levoglucosan, Furfural) and 21 lignin derivatives (Guaiacol, Syringol) were detected. Thermogravimetric analysis indicated that the yield of char increased and maximum wieght loss rate decreased with increasing lignin portion of solid residue. Therefore, structure of lignin was condensed effectively by sulfuric acid and by high concentration of acid.

• Journal of the Korea Organic Resources Recycling Association
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• v.1 no.2
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• pp.287-298
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• 1993

In this study, generation characteristics and distribution situation of the animal fat residue were investigated to identify it's management problems and to propose alternatives for the recycling and final disposal. Generation sources were the meat distribution net-work including about 170 slaughterhouses, 280 meat-packing plants, thousands of meat shops and restaurants etc. The daily total amount of the animal fat residue is about 700 ton/day. More than 60% of the generation sources were concentrated in Seoul metropolitan area. The residue was collected by about 300 men using old-fashioned devices like handcarts, bike and auto bike, transported to the recycling plants by about 60 collection agencies. The residue was processed to produce by-products such as grease, tallow, animal feed ingredient in the recycling plants. At present, however, a great number of unlicensed, and mostly small rendering processors without having pollution control facilities do the unlawful business. These small, old fashioned and unorganized businesses are creating environmental problems by disposing the waste in improper ways such as open burning and dump. Improvement of the distribution network, the large-scale plants, and the estabilishing proper infrastructures were suggested to overcome the problems for the sound fat residues reprocessing industry.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.336-342
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• 2012

This study was carried out in order to compare the residue levels of pesticides among lettuce, kale and perilla leaf depending on the morphological characteristics of plant. Residue levels were investigated at the zero, second, fifth days after last application, 9 species of systemic or non-systemic pesticide were twice applied with 7 days interval by knapsack power sprayer with 2 heads fan shape nozzle. Ratios of leaf area to weight ($cm^2$ $g^{-1}$) were 58 of perilla leaf, 27 of lettuce and 23 of kale. Ratios of leaf area to weight of perilla leaf was 2.1 times higher than that of lettuce. Residue levels of perilla leaf were 1.3 to 2.3 times higher than those of lettuce at the day of spraying and 1.3 to 3.3 times higher at the fifth day. Therefore the differences of pesticide residues between perilla leaf and lettuce were affected by the ratio of leaf area to weight. Residue levels in lettuce were 2.4 to 7.3 times higher than those in kale at the day of spraying because the adhesive effect of pesticide particles on kale leaf was low.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.9-22
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• 2020

This study was designed to use the safety management data for residual pesticides in imported banana based on the investigation of pesticide residue detection of agricultural products with different origins in the Republic of Korea. From the USA, EU, UK, Japan and Korea from 2007 to 2018, the results of banana residue pesticides were summarized into detected pesticides, number of inspections, number of pesticide detection cases, and the amount of detected pesticide residue. A total of 109 pesticides were detected for the pesticide residue and pesticide detection rate was 4.58% in 206,894 cases. The detection rate was ranged within 10.62-24.62% for chlorpyrifos, imazalil, methyl-bromide, azoxystrobin, carbendazim, pretilachlor and thiabendazole. Among them, chlorpyrifos was detected most often followed by imazalil, azoxystrobin, thiabendazole, bifenthrin and carbendazim. According to the results of monitoring data for bananas in EU, Japan, USA, UK and Korea, the kinds of detected pesticides were 85, 57, 23, 18 and 8, respectively. Azoxystrobin, bifenthrin and chloropyrifos were found in monitoring data of all countries. Fourteen and twelve pesticides were detected in bananas from Costa Rica and Ecuador, respectively. Imazalil and thiabendazole were detected in 16 and 11 origins, respectively. Myclobutanil and iprodione were detected in four and two countries, respectively. In bananas from Costa Rica, azoxystrobin and bifenthrin were detected 11.8 and 9.8%, respectively, and the detection rate of azoxystrobin was 19% in bananas from Colombia. Chlorpyrifos was detected 22.7, 13.3 and 10.8% in bananas from Belize, Colombia and Costa Rica respectively. Myclobutanil was detected in bananas from Colombia and Costa Rica with the rate of 17.9 and 10.4%, respectively.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.860-865
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• 1995

This study was conducted to extract and isolate the polysaccharides from buckwheat. Also the sugar composition of the polysaccharides was investigated. The soluble and indigestible polysaccharides were isolated from supernatant and residue after enzyme treatment of raw, roast and steam buckwheat. The yields of low molecular weight soluble polysaccharides(LMS-P: MW<10 Kda) and high molecular weight soluble polysaccharides(HMS-P: MW>10 Kda) were $74.9{\sim}84.2%$ and $5.5{\sim}9.4%$, respectively. The yields of indigestible polysaccharides were low molecular weight insoluble polysaccharides; $0.8{\sim}4.2%$, crude hemicellulose; $3.2{\sim}9.6%$, alcohol insoluble hemicellulose; $0.9{\sim}1.7%$, residue; $2.0{\sim}2.4%$, respectively. The free sugars were detected in the soluble polysaccharides and low molecular weight insoluble polysaccharides but were not detected in the crude hemicellulose, alcohol insoluble hemicellulose and residue. The protein of all fraction were detected and the content was $1.0{\sim}18.9%$. The main sugar of soluble polysaccharides was glucose and the indigestible polysaccharides were composed of glucose, arabinose, rhamnose, xylose, mannose and galactose.

• Journal of Ecology and Environment
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• v.41 no.12
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• pp.336-344
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• 2017

Background: Because of climate change, interest in the development of carbon pools has increased. In agricultural ecosystems, which can be more intensively managed than forests, measures to control carbon dioxide ($CO_2$) emission and absorption levels can be applied relatively easily. However, crop residues may be released into the atmosphere by decomposition or combustion. If we can develop scientific management techniques that enable these residues to be stocked on farmland, then it would be possible to convert farmlands from carbon emission sources to carbon pools. We analyzed and investigated soil respiration (Rs) rate characteristics according to input of carbonized residue of red peppers (Capsicum annuum L.), a widely grown crop in Korea, as a technique for increasing farmland carbon stock. Results: Rs rate in the carbonized biomass (CB) section was $226.7mg\;CO_2\;m^{-2}h^{-1}$, which was 18.1% lower than the $276.9mg\;CO_2\;m^{-2}h^{-1}$ from the red pepper residue biomass (RB) section. The Rs rate of the control was $184.1mg\;CO_2\;m^{-2}h^{-1}$. In the following year, Rs in the CB section was $204.0mg\;CO_2\;m{-2}h^{-1}$, which was 38.2% lower than the $330.1mg\;CO_2\;m^{-2}h^{-1}$ from the RB section; the control emitted $198.6mg\;CO_2\;m^{-2}h^{-1}$. Correlation between Rs and soil temperature ((Ts) at a depth of 5 cm) was $R^2=0.51$ in the RB section, which was higher than the other experimental sections. A comparison of annual decomposition rates between RB and CB showed a large difference, 41.4 and 9.7%, respectively. The results showed that carbonization of red pepper residues reduced the rates of decomposition and Rs. Conclusions: The present study confirmed that the Rs rate can be reduced by carbonization of residue biomass and putting it in the soil and that the Rs rate and Ts (5 cm) were positively correlated. Based on the results, it was determined that approximately $1.2t\;C\;ha^{-1}$ were sequestered in the soil in the first year and $3.0t\;C\;ha^{-1}$ were stored the following year. Therefore, approximately $1.5t\;C\;ha^{-1}year^{-1}$ are expected to be stocked in the soil, making it possible to develop farmlands into carbon pools.