• Applied Biological Chemistry
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• v.20 no.2
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• pp.236-241
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• 1977

Analytical method of carbofuran (2,3-dihydro-2, 2-dimethyl-7-benzofuranyl methyl carbamate) residues and its persistence in rice seeds, rice seedlings, rice plants and soils were studied by gas-liquid chromatographic analysis using electron capture detector. 1. The effective column material for clean-up is Florisil (5% $H_2O$)+Alumina (4% $H_2O$)+absorbent mixture with rinsing the first 300l of eluants to remove impurities in the column materials. 2. The method of applying an gelatin encapsulated carbofuran to the root zone of rice plant is the longest persistence in its residues. 3. By seed treatment, no carbofuran residues were detected in rice seeds and seedlings. 4. The amounts of carbofuran residues in rice seedlings is in proportion to the soaking time of rice seedlings in carbofuran solution rather than the concentration of the chemical. 5. Applying carbofuran by root zone has the higher and the loger residual effect than broadcast. 6. Persistence of carbofuran in the high clay content soil is longer than in the low clay content soil. 7. No carbofuran residue was detected in rough rice at havesting time.

• Analytical Science and Technology
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• v.28 no.5
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• pp.309-316
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• 2015

The analytical method of lead in plasma by ICP-MS was validated after securing environment within class 1,000 classification. We tested specificity and accuracy of within-run and between-run. According to measurement of the amount of suspended particulates in a clean room, 0.3~62 particles were detected in 0.3 µm size while 0.0~28.3 particles were observed in 0.5 µm size. Total suspended particulates met required environment with up to 90.3 particles. The MDL (Method detection limit) of the sample which has been fabricated using fetal bovine serum (FBS) blank was 1.77 ng/L, and LOQ (Limit of quantification) was 5.55 ng/L. The slope, intercept and correlation coefficient of the calibration curve were y=1.09×10⁻³x+4.88×10⁻² and r=0.9999, which showed good correlation. The specificity, within-run and between-run accuracy satisfied the standard at more than 50 ng/L. The average lead concentration in plasma of the general people, current workers and retired workers was 55.4 ng/L, 440 ng/L, and 132 ng/L.

• Analytical Science and Technology
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• v.27 no.4
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• pp.201-212
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• 2014

Polycyclic aromatic hydrocarbons (PAHs) that are carcinogenic and persistent will be restricted in consumer products from December 27, 2015 by EU REACH regulation. Pretreatment using Soxhlet extraction and quantitative analysis by GC-MS were studied to develop the method for analyzing 18 PAHs in consumer products as well as to detect the amounts and the kinds of PAHs in consumer products such as grips of a bag and a hammer, a cable and a plastic sandal. Linearity and precisions were evaluated by analyses of the standard PAH solutions ranging from 0.3125 mg/L to 5.00 mg of each of 18 PAHs. Linearity of resulting standard curves for all 18 PAHs were obtained with $R^2$ above 0.999. Precisions of the retention times and the peak areas were found to be 0.00%~0.05% and 1.16%~3.69% of relative standard deviations, respectively. The recoveries for spiked samples were all around 95%~105% after Soxhlet extration using three different solvents such as dichloromethane, hexane and toluene. The limits of quantitation for 18 PAHs in solutions and polymer samples by GC-MS were evaluated to be 0.327 mg/L (Benzo[ghi]perylene)~0.464 mg/L (Acenaphthylene) and 1.635 mg/kg (Benzo[ghi]perylene)~2.32 mg/kg (Acenaphthylene) based upon dilution factor of 5, respectively. Under the developed analytical method, only trace amounts of phenanthrene were detected in three samples while 15 kinds of PAHs including phenanthrene were detected in a grip of hammer with concentrations of maximum 83.4 mg/kg of Phenanthrene and minimum 8.5 mg/kg of Acenaphthylene. Further studies are needed to decrease the quantitation limit and to check the feasibility of decreasing Soxhlet time as well as to demonstrate cases that the clean up is required.

• The Korean Journal of Pesticide Science
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• v.18 no.2
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• pp.69-78
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• 2014

In the present study, we developed an official individual analytical method for cymoxanil using HPLC/UVD, respectively in different representative crops. Individual analytical methods for these pesticides are not included in the Korea food code. The samples were extracted with acetonitrile, concentrated and partitioned with dichloromethane and saturated sodium chloride solution. For cymoxanil, extracts were concentrated and clean-up through silica gel column chromatography with dicloromethane/acetone (60/40 v/v) and subjected to instrumental analysis. The limit of detection (LOD) for cymoxanil were 0.1 ng and 1 ng respectively and limit of quantitation (LOQ) were 0.02 mg/kg. Recoveries for cymoxail ranged from 79.6~107.6% respectively, at fortification level of 0.02 mg/kg (LOQ), 0.2 mg/kg (10 LOQ) and 1.0 mg/kg (50 LOQ) and the coefficient of variation (CV) was less than 10%, regardless of sample types. These results were further confirmed with LC/MS. The proposed simultaneous analysis method is reproducible and sensitive enough to determine the residues of cymoxanil in the agricultural commodities. According to the validation data and performance characteristics and high sample throughput, the proposed method is suitable for routine application.

• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.221-227
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• 2016

This study was conducted to investigate residual organochlorine pesticides in green house soil and green perilla leaves. Extraction and clean-up method were developed using the modified QuEChERS method for residual organochlorine pesticides (ROCPs) in soil and green perilla leaves. Recovery and limit of quantitation (LOQ) of ROCPs in greenhouse soil and green perilla leaves were 76.3-113.4 and 79.4-107.3%, 0.03-0.24 and $0.33-0.50{\mu}g/kg$, respectively. Detected ROCPs in greenhouse soil were dieldrin and endosulfan sulfate, the residue were 1.6-9.2 and $22.0-87.8{\mu}g/kg$, respectively. But two pesticides in all green perilla leaf samples were not detected. These results showed that ROCPs residue in greenhouse soil was lower than the level of bioaccumulation occurring.

• Journal of Korean Neurosurgical Society
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• v.29 no.5
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• pp.668-674
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• 2000

Objective : The classic and accepted surgical method of compound comminuted depressed skull fractures (FCCD) involves total resection of all the contaminated bone and fragments at the fracture site. A second operation for cranioplasty is then performed at a later date. However, we have believed that primary repair of these bony defects can be achieved by the replacement of bone fragments at the time of the initial debridement, and this can be accomplished without danger to patient. The authors retrospectively reviewed the surgical results to assess the advantages and disadvantages, and also propose the selection criteria of replacement of fractured bone fragments as a primary procedure in FCCD. Materials and Methods : The authors analyzed the data extracted from medical records, and radiological findings in 22 of 71 patients with FCCD, who underwent immediate replacement of fractured bone fragments between April 1993 and October 1998. The mean follow-up period was 13.7 months. The selection criteria for the operation included the patients with mild to moderate severity, regardless of the degree of contamination or dural violation, which presented in hospital within 24 hours of injury. Results : The ages of the patients varied from 4 to 63 years, and there were 20 males and 2 females. Seventeen of 22 patients were fully conscious on admission and the others also had relatively good Glasgow coma scales. Sixteen fractures were located in the frontal area, 9 with involvement of the frontal sinuses, and 6 in the parietal and temporoparietal areas. Of the 22 patients, 8(36.3%) had dural lacerations with 3 of these requiring patching with pericranium, and 12(54.5%) had intracranial hematoma requiring wide craniotomy. The degree of wound contamination was also variable. Fifteen patients had relatively clean wounds, while seven(31.8%) had seriously contaminated wounds with soil, sand, hair, and wood. Only one patient(4.5%) developed infection, and the bone fragments were removed. All wounds healed primarily without pulsatile defect, the skull has remained solid, and no complications have occurred, except the infected case. Conclusion : It is proposed that bone fragments removal for FCCD, regardless of the degree of contamination or dural violation, is not necessary and that primary bone fragments replacement avoids a second operation for cranioplasty.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.4
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• pp.281-288
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• 2011

Recently, researches that a variety of contaminants in water are removed by sonolysis technology with oxidation and pyrolysis process from cavitation were conducted. However, there are few studies for sonochemical treatment by a pilot-scale ultrasound system. This research focused on developing pilot-scale ultrasound systems, which could be an continuously effective treatment for a large volumes of contaminants, and demonstrating the feasibility of utilizing these systems to remove naphthalene from groundwater. V-120 type reactor was found to be 1.4~2.2 times higher effective than the normal type. A total of three different pilot scale's systems consisted of installing effluent and irrigation water in order to be a continuos system, including supplemental additives, and applying a V-120 type reactor and a external cooling cycle system. Naphthalene levels treated by three systems were lower than a recommended guideline of naphthalene for drinking water in EPA. Especially, the naphthalene removal efficiencies of PS1 and PS2 systems were over 97%. The pilot-scale continuous ultrasound clean-up system delivered over 84~95% naphthalene removal efficiency for treatment of 10~20 liter of groundwater. In addition, the ultrasound system could be successfully applied to the conditions of artificial and genuine groundwater contaminated with naphthalene.

• The Korean Journal of Pesticide Science
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• v.17 no.2
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• pp.84-93
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• 2013

Validated analytical methods for isopyrazam are meager or lacking. In the present study, a single residual analytical method was developed for isopyrazam in selected commodities. Isopyrazam was analyzed in brown rice, soybean, green pepper, mandarin, cucumber, and Korean melon. We tried different solvents and methods through extraction, partition and purification steps to obtain best analytical results. For isopyrazam samples were extracted with acetonitrile, concentrated and partitioned with n-hexane, clean-up using florisil with n-hexane/ethylacetate (70/30) and analyzed with HPLC/UVD. The limit of quantitation (LOQ) for isopyrazam was 1.0 ng (S/N > 10) and method LOQ (MLOQ) was 0.04 mg $kg^{-1}$. Recovery ranged through 81.0~105.3% (syn-isomer) and 80.8~105.6% (anti-isomer) at fortification level of 0.04 (MLOQ), 0.4 (10 ${\times}$ MLOQ), and 2.0 (50 ${\times}$ MLOQ). The coefficient of variation (CV) for isopyrazam was less than 10% regardless of sample types. These results were further confirmed with LC/MS, respectively. The proposed method is highly reproducible and sensitive and is suitable for routine analysis.

• The Korean Journal of Pesticide Science
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• v.21 no.1
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• pp.75-83
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• 2017

The single residue analytical method was developed for determining fungicide pencycuron residues in various agricultural commodities with high-performance liquid chromatography (HPLC). Pencycuron residue was extracted with acetone from representative crops such as Korean cabbage, apple, brown rice and green pepper. After ethyl acetate/n-hexane partition and subsequent clean-up with silica gel chromatography, pencycuron residue was quantified by reversed phase HPLC with UV detection at 240 nm. The suspected residue of pencycuron was confirmed using selected-ion monitoring (SIM) LC/mass spectrometry (MS). Instrumental limit of quantitation (ILOQ) and method LOQ (MLOQ) were set at 2 ng and 0.02 mg/kg, respectively. Overall recoveries of pencycuron from different crop samples fortified at three levels (MLOQ, 10MLOQ, 100MLOQ) were 72~108%. This proposed method could be useful as official analytical method for quantification of pencycuron residues in agricultural commodities.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.9
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• pp.659-666
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• 2014

The purpose of this study was to suggest a standard design procedure of landfarming for clean-up of oil-contaminated soils. The standard design procedure consisted of four main phases; soil characterization, determination of contaminated soil volume, determination of nutrient and microbial doses, and estimation of the total remedial period. This study selected standard design parameter values or ranges among various forms used in environmental engineer communities. Those were determination procedures for the contaminated soil volume, the initial contamination concentration and nutrient doses. The suggested standard design procedure were applied for a landfarm design for remediation of a real oil-contaminated site. Soil texture of the site was classified as sandy clay loam and sandy loam. Total nitrogen and total phosphorus were estimated to be 57.01 mg/kg and 83.40 mg/kg, respectively. Also the viable bacterial numbers was assessed to be $1.78{\times}10^4CFU/g$ dry soil. The amount of TPH contaminated soil was estimated to be $4,092m^3$. With the application of remedial factors, it was estimated that the contaminated soil could be treated through 9 batches with a duration of 315 days for a landfarming unit of $15m{\times}40m{\times}1m$. The amount of liquid microorganisms and fertilizers were recommended to be 4,025L and 4,641kg, respectively.