• Analytical Science and Technology
• /
• v.5 no.2
• /
• pp.153-158
• /
• 1992

In this work, we developed supercritical fluid chromatographic methods for the samples which are difficult to analyze with conventional GC or HPLC. Long-chain Hydrocarbons, mink oils and soybean oils unsuitable for GC because of their low volatility or limited thermal stability were separated by SFC due to the high solvating properties of supercritical carbon dioxide fluids. In our research, a new method for the analysis of polar fatty acids and pesticides was developed. This method should be used to overcome problems with polar samples in SFC.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.50 no.4
• /
• pp.17-24
• /
• 2008

Exposure risk assessment of pesticide molinate using the RICEWQ model in a rice paddy plot was performed to observe the effects of various water and pesticide management scenarios. Several scenarios were developed to represent the specific water and pesticide management practices of rice cultivation in Korea. The results of the scenario analysis using the RICEWQ model simulation from the previous studies were analysed. The molinate risk for aquatic organisms is evaluated by the ratio of the predicted environmental concentration(PEC) and the predicted no-effect concentration(PNEC). The results showed that the no-effect periods for aquatic organisms for the deep, shallow and very shallow irrigation conditions were 33.3, 28.9 and 25.6 DATs for the lable rate application and 36.4, 33.7 and 30.8 DATs for the double lable rate application, respectively. The higher application rate showed greater exposure risk to the aquatic organisms. Based on this study, the withholding period of molinate practiced in Korea, that is 3 to 4 DATs, must be much longer. The results of this study can be used for the non-point source pollution control and environmental policy making regarding pesticides.

• The Korean Journal of Ecology
• /
• v.21 no.1
• /
• pp.15-26
• /
• 1998

This study was conducted to analyze arthropod community patterns in smallrice fields managed by different cultural methods [Conventional and Low Input Sustainable Agriculture(LISA)] in Suwon in 1995 and 1996. A half of nitrogen fertilizers and a quarter of pesticides were applied in the LISA field compared to in the conventional field. Total 15 orders and 43 families of arthropods were collected in two years. No differences were found in arthropod abundance and arthropod species composition between two differently practiced fields. The arthropod community was analyzed using guild categories. The arthropods were found in the order of 'pest(phytophag)>natural enemy>non-pest' in their densities. The pest species were mainly Homoptera and dominated by Delphacidae (Nilaparvata lugens Stal and Sogatella furcifera Horvath). They constituted > 80% of pest abundance. The spider was the most dominant group in the natural enemy and constituted > 90% of natural enemy abundance. Hunting spiders constituted > 60% of spider abundance and were dominated by Pirata subpiraticus Bos. et Str.(Lycosidae). Pachygnatha clerki Sundevall(Tetragnathidae), Gnathonarium dentatum Weider and Ummeliata angulituberis Oi(Erigonidae) were the dominant species in webbing spiders.

• The Korean Journal of Community Living Science
• /
• v.28 no.4
• /
• pp.547-559
• /
• 2017

This study was conducted to investigate the perception about the construct in the Theory of Planned Behavior using In-depth interview for 24 housewives with elementary school children. Most housewives did not have an intention to buy organic vegetables more in the future than in the present. They showed positive attitudes toward organic vegetables in terms of non-use of pesticides and fertilizers, taste, nutrient content, freshness, mental health, and protection of the environment. They showed negative attitudes toward organic vegetables in aspect of price, credibility of organic vegetables, differences in nutrients, appearance, size, perishability, and accessibility. Children, especially those with diseases, were the most influential persons to their mothers for buying organic vegetables. Housewives' negative attitudes toward organic vegetables were barriers for buying more organic vegetables and they were not willing to overcome these barriers actively. Therefore, government policy and nutrition education to change attitudes is needed to increase consumption of organic vegetables.

• Journal of the Korea Safety Management & Science
• /
• v.12 no.3
• /
• pp.27-35
• /
• 2010

In this study, we have developed the database of safety and health information for pesticide active ingredients used in Korea. There were 1,283 pesticide items among which 296 were found to be out of use in current. A total of 349 pesticide ingredients were being used in Korea. The database consists of 32 types of information including chemical characteristics, acute toxicity, chronic toxicity (carcinogenic and reproductive toxicity), specific symptoms by exposure route and first aid. When pesticide ingredients were assessed in terms of key properties such as color, odor, acute toxicity, carcinogenic and reproductive toxicity, they were white, colorless and odorless, in general. When ingredients were classified by category of acute toxicity, 'Non-hazardous' represented 29%, followed by 'Slightly hazardous' at 16%, 'Moderately hazardous' at 14%, 'Highly hazardous' at 5%, and 'Extremely hazardous' at 2%. 85 out of 349, or 24% of ingredients were found to be possibly carcinogenic to human. This database is expected to provide an easy access for farmers, agriculture supervisors, researchers and consumers, and it can ultimately be used as basic data on farmer's safety and health.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.38 no.1
• /
• pp.1-5
• /
• 2019

Bee's population is declining and disappearing at alarming rate. There are many factors responsible for declining the population of bees including diseases, natural enemies, environmental conditions and pesticides. Insecticides play its role dramatically for their population decline and neonicotinoid insecticides are critically important due to their wide application for pest control. Keeping in view of above problem, effect of neonicotinoid insecticides on olfactory learning behavior in Apis mellifera was observed using Proboscis Extension Reflex (PER) method. In this method, bees were harnessed in centrifuges tubes and feed on insecticides mixed sugar solution after three hours hunger. Bees were checked by feeding on non-treated sugar solution to observe PER response. Minimum proboscis extension was observed for acetamiprid and imidacloprid with 26% and 20% respectively at their recommend field doses while it was maximum for dinotefuran and thiamethoxam with 73% and 60% respectively. Only 40% bees showed response when exposed at 1/10 concentration of field dose for imidacloprid and the least at 1/100 of field dose. At control (Sugar solution) about 90% bees showed PER response. Among these neonicotinoid insecticides tested, imidacloprid and acetamiprid were the most damaging which impaired the olfactory learning performance in Apis mellifera.

• The Korean Journal of Emergency Medical Services
• /
• v.24 no.3
• /
• pp.117-128
• /
• 2020

Purpose: This study analyzed the information and accessibility of toxic substances provided to Internet websites. Methods: From August 1, 2020, to August 31, 2020, we analyzed eight internet websites regarding toxic pharmaceuticals, pesticides, and chemicals. The website-evaluation criteria were divided into five categories for information and five categories for website convenience. Results: All eight websites about toxic substances were hosted by reliable institutions or organizations and provided accurate information in terms of informational relevance. The website run by the Safety and Health Corporation scored the highest with 100points. Analysis of the websites' accessibility to non-members' revealed that six (75.0%) were accessible, but two (12.5%) provided only limited information. Access to information through mobile apps was only available in three of the eight cases (37.5%). Conclusion: This study can be used as a reference for Internet websites about toxic substances. Toxicological information that can be viewed only with membership and manager approval requires membership in advance of viewing. In addition, emergency medical personnel working at a site or hospital should be familiar with the characteristics of toxicity information retrieval.

• Journal of Biosystems Engineering
• /
• v.35 no.4
• /
• pp.244-249
• /
• 2010

This study was conducted to define the optimal Lycium chinense miller washing method for developing the Lycium chinense cleaner and we analyzed the Lycium chinense miller washing characteristics for removing pesticides and microorganism according to washing methods; habitual washing method, air bubble washing method and nozzle spray washing method. The results were summarized as follows; 1. In case of measuring physical properties according to the varieties, maximum yield strength of Hokwang was 2.562 kgf, minimum yield strength of Hokwang was 0.269 kgf and average yield strength was about 1 kgf. 2. In case of measuring change of bacteria according to washing methods, the number of bacteria of non-washing method was more than the number of bacteria of habitual washing method or mechanical washing method and the number of nozzle spray washing method was least. 3. Ahjoksiseuteurobin of 0.218 ppm was detected in the untreated sample, 0.051 ppm was detected in the habitual washing method, 0.047 ppm was detected in the air bubble washing method and 0.034 ppm was detected in nozzle spray washing method. Every amount detected were less than 2 ppm that is reference value and the detected amount was least in case of nozzle spay cleaning method. Cypermethrin of 0.772 ppm was detected in the non-cleaned sample, 0.089ppm was detected in habitual washing method, 0.26 ppm was detected in the air bubble washing method and 0.292 ppm was detected in the nozzle spray washing method. Every detected amount of Cypermethrin were less than 5 ppm that is reference value and the detected amount was least in case of habitual washing method.

• Korean Journal of Organic Agriculture
• /
• v.19 no.spc
• /
• pp.263-266
• /
• 2011

Crop protection strategies in organic horticulture aim to prevent insect pest and plant disease problems through utilization of non-chemical based control means. In order to develop a model for management of plant diseases and insects in organic cucumber cultivation, we compared efficacies between chemical pesticide spraying system and biological control means in semi-forcing and retarding cucumber cultivation during 2005 and 2006. Conventional chemical spray program using various chemical pesticides was applied 5 - 10 days intervals, while two different non-chemical pesticide application programs using two formulated biopesticides Topseed$^{TM}$ and Q-fect$^{TM}$, Suncho$^{TM}$, and Sangsungje$^{TM}$ (biocontrol agents 1) and using egg-yolk and cooking oil(EYCO), Bordeaux mixture, Suncho$^{TM}$, and Sangsungje$^{TM}$ (biocontrol agents 2) were applied 5 - 7 days intervals during entire cucumber cultivation period. Efficacy of both biocontrol agents programs was effective to comparable to conventional chemical pesitice spray program to control plant diseases such as powdery mildew and downy mildew as well as insect pests such as aphids and thrips which are known as major threats in cucumber organic cultivation. In this study, we established and evaluated an effective and economic crop protection strategy using various biological resources can be used to control plant diseases and pests simultaneously in organic cucumber cultivation field.

• Korean Journal of Food Science and Technology
• /
• v.41 no.6
• /
• pp.722-726
• /
• 2009

The residue distribution ratio of pesticides among the flesh, stem and leaves of hot peppers were investigated to assure the safety of pepper powder and pepper leaves. Mixed solutions of chlorothalonil (wettable powder), kresoximmethyl (water dispersible granules) and procymidone (wettable powder) were applied once onto pepper plants in a plastic film house. After 7 days, the fruits and leaves were harvested and the fruits were divided into the flesh and stems. Pesticide residues in each pepper part were then analyzed by gas chromatography. The results showed that the concentration ratios of the chemicals in the flesh:stem and flesh:leaf ranged from 1:2-5 and 1:11-39, respectively, depending on the chemical evaluated. The observed flesh:stem ratio indicates that the pesticide content of the pepper powder product can increase by 20% if pepper stems are included in the powder product. The Korea Food and Drug Administration does not set a pesticide maximum residue level (MRL) for pepper leaves if a residue ratio in leaves over flesh is more than ten times. Results from this study support non-MRL status on the pepper leaves for the studied pesticides. Additionally, we recommend that the chlorothalonil product of a wettable powder type include the phrase "prohibition of distribution or sale for pepper leaves as food" because chlorothalonil highly resided in pepper leaves as more than twenty-four times that is a criterion level to determine an inclusion of the phrase in the label of pesticide product.