• Analytical Science and Technology
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• v.7 no.3
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• pp.395-402
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• 1994

Benomyl(Methyl-1-(Butyl Carbamoyl)-Benzimidazole-2-yl-Carbamate) is widely used as pre- and post-harvest pesticide. It converts into MBC(Carbendarzime:Benzimidazole-2-yl-carbamate) and butyl-isocyanate in mild condition. In this study, three analytical methods for MBC were compared in view of detectability, correctness, and sensitivity. The first and second are HPLC analytical method employing the UV detection of MBC. Our new third method was modification of PFBB(pentafluoro-benzylbromide) derivatization method with GC-ECD & MSD. The average recoveries and detection limit of MBC in the newly modified method are 95% and $0.001{\mu}g/g$ in whole bean and bean sprouts respectively. This new method prevent pesticide analysis from misdetecting in bean and bean sprouts.

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

• Analytical Science and Technology
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• v.12 no.6
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• pp.577-582
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• 1999

The blood toluene concentration was determined by using the GC/MSD with HS-SPME technique in postmortem blood, quantitatively. Butane gases was analyzed by using the GC/FID with HS technique in postmortem blood, qualitatively. Seventy five cases of dead associated with inhalation of glue or butane gases happened in Korea for the last 3 years (1996-1998). In 27 cases of deah due to glue sniffing, nine persons died as a result of a fall while intoxication and their blood tolucne concentration was fairly high in the range of $1.3{\sim}21.6{\mu}g/mL$. In case of death due to butane sniffing, fifty four persons died of acute butane gases inhalation or suffocation, and 6 persons died of butane gases as well as glue inhalation.

• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.378-381
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• 2012

The monitoring of the uniconazole residual pesticide for agricultural products was conducted by multiclass pesticide multiresidue methods. Samples were collected from June to November, 2011. Uniconazole pesticide was detected in 49 samples from a total of 3,939 samples. The amount of uniconazole pesticide ranged from 0.09 to 17.89 mg/kg in 49 samples. This method was described for the simultaneous determination of uniconazole by gas chromatography with a nitrogen phosphorus detector (GC-NPD) and mass spectrometry (MS). The limit of detection and quantification were 0.006 and 0.018 mg/kg GC-NPD, respectively. For an evaluation of the GC-NPD method, uniconazole spiked into gyeojachae at a level of 0.5, 5 mg/kg was determined. The recoveries of uniconazole by the GC-NPD method ranged from 83.4 to 101.4%. The results indicate that the method of simultaneous analysis is applicable to uniconazole analysis.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.1
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• pp.41-47
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• 2017

After $SF_6$, which is being used in power equipment as an insulating material, is classified as one of the 6 major greenhouse gases, the maintenance and the refinement of used $SF_6$ started to get attention. In regard to this, KEPCO Research Institute (KEPRI) is developing $SF_6$ recovery and refinement technology starting with establishing a comprehensive $SF_6$ analysis system. With the analysis system, qualitative and quantitative analyses of the purity and the impurities of $SF_6$ before and after recovery, and before and after refinement have been carried out. The analysis system is comprised of GC-DID (Gas Chromatograph -Discharge Ionization Detector) for trace impurities analysis, GC-TCD (Thermal Conductivity Detector) for analyses of $SF_6$ purity and major impurities concentration from several hundred ppm up to percent range, GC-MSD (Mass Selective Detector) for analyses of impurities not included in standard gas, FT-IR (Fourier Transform-Infrared) Spectrometer for analysis of HF and $SO_2$, and moisture analyzer for analysis of moisture below 100 ppm. With this analysis system, complete analysis method of $SF_6$ has been established. This analysis system is being used in the maintenance of power equipment and the development of $SF_6$ recovery and refinement technologies. In this paper, the analysis results of four samples - gas and liquid phase $SF_6$ samples from a $SF_6$ refinement system before and after refinement are presented.

• Analytical Science and Technology
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• v.13 no.1
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• pp.55-65
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• 2000

In this study, we collected the tap water that treated from water plant in Seoul, Incheon, Taejon, Kwangju, Taeku and Pusan and supplied each house. The sampling period was June and September, 1997. The concentration of THMs formed by chlorination in drinking water was determined with the purge and trap method with GC/MSD recommended by the us EPA 542.2 method. Chloroform is the most of THMs (47.43%~93.11%) and the content order is bromodichloromethane > chlorodibromomethane > bromoform. In Incheon, Taejon, Kwangju, Taeku and Pusan, the content of bromodichloromethane, chlorodibromomethane and bromoform was higher than Seoul. But, in June and September, the concentration of THMs in six cities is not over Korea Drinking Water Regulation $100{\mu}g/L$. The calculated human exposure for each substances were chloroform $6.14{\times}10^{-4}mg/kg/day$, bromodichloromethane $1.01{\times}10^{-4}mg/kg/day$, chlorodibromomethane $0.29{\times}10^{-4}mg/kg/day$, bromoform $0.01{\times}10^{-4}mg/kg/day$ and THMs $7.98{\times}10^{-4}mg/kg/day$.

• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.402-411
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• 2012

Natural Bokbunja is used as a material of oriental medicine which it obtains from Rubus or Raspberry. Natural Bokbunja Rubus has natural odor and taste, natural color, and pharmaceutical & chemical characteristics. This experiment tested antimicrobial experiment against microbe and dye experiment against fiber using natural Bokbunja extract. Some conclusions from this characteristics experiment were obtained as follow. The result of antimicrobial experiment could know that ATCC-001(staphylococcus aureus) does not show nearly from 72hrs after cultivation test and ATCC-002(aspergillus niger) shows to propagate continuously according to passage of time. Also, the result of dye experiment could know that cotton and silk using alum mordant($Al_2(SO_4)_3{\cdot}13-14H_2O$) against fiber shows in direction of light beige color. The result of instrument analysis ascertained inorganic components of K(221.100ppm), Mg(17.920ppm), Ca(5.129ppm), Na(2.940ppm), Si(0.638ppm) etc from Bokbunja with ICP/OES, and ascertained organic components of boric acic(1.711), silane(2.142), pyrazole(3.481), propyl isothiocyanate(2.565), furfurole(11.521) etc from Bokbunja with GC/MSD.

• Korean Journal of Veterinary Research
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• v.50 no.3
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• pp.197-203
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• 2010

Pesticides are useful to eliminate harmful insects and grow crops however, misuse and abuse of pesticides may cause a death of wild birds, livestock, and companion animals. We analyzed residual pesticides in the ingesta and tissues from the dead wild birds, livestock, and companion animals which were suspected pesticide poisoning based on the diagnosis of the Animal Disease Diagnostic Center of National Veterinary Research and Quarantine Service (NVRQS). The samples were primarily brought to NVRQS from local communities and veterinary diagnostic laboratories. The 231 suspicious samples of pesticide poisoning based on the necropsy were analyzed by GC/NPD, GC/FPD, GC/ECD, or GC/MSD in 2008 and 2009. Pesticides were identified from the 55 samples of total 143 samples analyzed in 2008 and from the 34 samples of total 88 samples analyzed in 2009. The pesticide identification rates in 2008 were higher than the rates in 2009. It may have relevance to the increased samples with the outbreak of avian influenza in 2008 in Korea. The concentrations of pesticides found in the dead animals varied and exceeded the respective $LD_{50}$ of pesticides in many cases. Monochrotophos, phosphamidon, and methomyl were the most common pesticides found and those pesticides are high rank sales in Korea. The cause of pesticide poisoning in animal is assuming a misuse and an abuse of commonly used pesticides in Korea.

• Korean Journal of Environmental Agriculture
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• v.14 no.1
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• pp.45-54
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• 1995

esters of the acid analytes were synthesized using $H_2SO_4$ as the catalyst. Efficiency of derivatization and instrumental molecular-response were compared with herbicides methylated with $BF_3-methanol$(14% W/V), $H_2SO_4-methanol$(33% V/V), and diazomethane. The molecular integrity of TFE-2,4-D, TFE-dicamba, and TFE-mecoprop, in the mixture, was confirmed by the GC/MSD method. The TFE-Esterification efficiency was maximized by adjusting the volume of $H_2SO_4$ the reaction time, and temperature. Optimal efficiency for the herbicide mixture was obtained by adding 1 ml of $H_2SO_4$ and 1 ml of TFE to the dried sample and allowing the reaction to proceed at $22^{\circ}C$ for 8 hr or using 0.5 ml $H_2SO_4$ and 1 ml of TFE at $60^{\circ}C$. For 120 min increasing the temperature and decreasing the reaction time were required for maximum esterification efficiency. The sensitivity of the GC/ECD to the TFE esters was about $2{\sim}20$ times greater than that to the methyl ester derivatives. The herbicides were extracted and esterified to TFE derivatives simultaneously from soil leachates previously spiked with the analytes. Herbicide recovery, peak resolution, and detector sensitivity were excellent without using column cleanup procedures.

• Analytical Science and Technology
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• v.23 no.2
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• pp.187-195
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• 2010

To assess health risk for the intake among residents after the Hebei Spirit oil spill, 16 Polycyclic Aromatic Hydrocarbons (PAHs) in seafood samples from oil contaminated bay were determined by Gas Chromatography-Mass Spectrometry (GC-MSD) and samples were personally collected and purchased by residents. Samples were hydrolyzed with KOH and extracted with methylene chloride. The extracted solution were cleaned up using silica/florisil column and 16 PAHs were eluted by methylene chloride : n-hexane (1:9) mixture and determined by GC-MSD in Selected Ion Monitoring (SIM) mode. The mean recoveries for 16 PAHs ranged from 79% to 85%. The 16 PAHs levels in 126 samples ranged from 0.17 to $6.04\;{\mu}g$/kg and the TEQBaP (Toxic EQuivalents) levels in 126 samples were calculated using benzo(a)pyrene toxic equivalency factor for individual 16 PAHs and ranged from 0 to $0.91\;{\mu}gTEQ$/kg. The average Benzo(a)pyrene dietary exposure of residents was $5.5{\times}10^{-8}\;mg/kg$ bw/day and the average PAHs chronic dietary exposure was $1.3{\times}10^{-5}\;mg$ TEQ/kg bw/day. The margin of exposure (MOE) and the excess cancer risk and were $1.8{\times}10^6$ and $9.8{\times}10^{-8}$, respectively. Therefore, the assessment result was considered as low concern for health risk.