• Archives of Pharmacal Research
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• 제6권1호
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• pp.7-16
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• 1983

A methadone-diazepam interaction study in rats was performed in which conjugated metabolites of methadone were analyzed using deuterated biosynthetic internal standards. Diazepam (5mg/kg) was given to rats through a cannulate djugular vein and a subcutaneous dose of methadone (10mg/kg) was given. Bile was collecte through the cannulate dbile duct over a period of 24 hours. The deuterium label of the internal standards was found to be stable under conditions of the prolonged incubation. There was no significant difference in the excretion of the metabolites between the control and the diazepam treated rats. Feasibility of using biosynthetic internal standards with selected ion monitoring was established for the drug metabolism and kinetic studies.

• Environmental Engineering Research
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• 제13권4호
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• pp.216-223
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• 2008

An efficient method for the simultaneous determination of eleven phenolic endocrine-disrupting chemicals (EDCs) present in wastewater influent samples was described. The 11 phenolic EDCs including alkylphenols, chlorophenols, and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring (GC/MS-SIM) following two work-up methods for comparison; isobutoxycarbonyl (isoBOC) derivatization and tert-butyldimethylsilyl (TBDMS) derivatization. The wastewater influent samples containing the 11 EDCs were adjusted to pH 2 with $H_2SO_4$ and then cleaned up with n-hexane. Next, they were subjected to solid-phase extraction (SPE) with XAD-4 resin and subsequently converted to isoBOC or TBDMS derivatives for sensitivity analysis with gas chromatography/mass spectrometry-selected ion monitoring (GC/MSSIM). Following isoBOC derivatization and TBDMS derivatization, the recoveries were 86.6-105.2% and 97.6-142.7%, the limits of quantitation (LOQ) for the 11 phenolic EDCs for SIM was 0.001-0.050 ng/mL and 0.003-0.050 ng/mL, and the SIM responses were linear with the correlation coefficient varying by 0.9717-0.9995 and 0.9842-0.9980, respectively. When these methods were applied to five selected wastewater influent samples, for isoBOC derivatization and TBDMS derivatization the ranges of concentration detected were 0.2-99.6 ng/mL and 0.4-147.4 ng/mL, respectively.

• Environmental Analysis Health and Toxicology
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• 제17권1호
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• pp.37-51
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• 2002

Eleven phenols including two chlorophenols, eight alkylphenols and bisphenol A were derivatized with isobutylchloroformate to form their isobutoxycarbonyl derivatives. Standard phenol mixture was concentrated for the isobutoxycarbonyl (isoBOC) derivatization and analysed by gas chromatography/mass spectrometry (GC/MS). The recoveries of the derivatization method of alkylphenols, chlorophenols, and bisphenol A were calculated by gas chromatography/mass spectrometry-selected ion monitoring mode using two work-up methods for comparison; shaking and heating method. The linear detector responses were obtained in the concentration range of 5∼400 ng, with correlation coefficients varying from 0.9755∼0.9981. Recoveries of the alkylphenols, chlorophenols, and bisphenol A were determined by gas chromatography/mass spectrometry-selected ion monitoring mode using two work-up methods for comparison ; the US-EPA method and the isoBOC derivatization method, Eleven phenols in water samples were extracted with dichloromethane and then concentrated. Also, solid-phase extraction (SPE) with XAD-4 and subsequent conversion to isobutoxycarbonyl derivatives for sensitive analysis with the selected ion-monitoring (SIM) mode. The recoveries were 85.1∼109.9％ and 90.3∼126.6％ for the US-EPA method and the isoBOC.

• 한국기계가공학회지
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• 제21권6호
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• pp.89-97
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• 2022

Ultrasonic metal welding has been widely used for joining lithium-ion battery tabs. Weld quality monitoring has been an important issue in lithium-ion battery manufacturing. This study focuses on the weld quality monitoring in ultrasonic metal welding with the longitudinal-torsional vibration mode horn developed newly. As the quality of ultrasonic welding depends on welding parameters like pressure, time, and amplitude, the suitable values of these parameters were selected for experimentation. The welds were tested via tensile testing machine and weld strengths were investigated. The dataset collected for performance test was used to train the multi-layer perceptron neural network. The three layer neural network was used for the study and the optimum number of neurons in the first and second hidden layers were selected based on performances of each models. The best models were selected for the horn and then tested to see their performances on an unseen dataset. The neural network models for the longitudinal-torsional mode horn attained test accuracy of 90%. This result implies that proposed models has potential for the weld quality monitoring.

• 대한한의학회지
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• 제20권1호
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• pp.44-51
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• 1999

Analysis of residual pesticides in herbal drugs was performed by GC-ECD and GC-MS. Especially, selected ion monitoring(SIM) technique was applied to increase the GC/MS sensitivity. Analysis of residual pesticides was determined sensitivity and selectively without any internal standard by setting the SIM technique to their characteristic fragments for quantitation ion and confirmation ion. The combination of two detector, GC-ECD and MS-SIM technique, is abailable for determining a multiclass residual pesticides in herbal drugs. The average recoveries through the method were $65.9%{\sim}99.7%$ in herbal drugs. The data of gas chromatographic analysis was compared with the limits of residual pesticides in herbal drugs and agricultural foods. 4. 4-DDT was detected above the limits to the residual pesticides in herbal drugs. Diazinon and EPN were detected, but the limits of residual pesticides were less than that of agricultural foods.

• Environmental Analysis Health and Toxicology
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• 제16권3호
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• pp.121-126
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• 2001

Analytical method of benzophenone (BP) in sediment and soil was developed by gas chromatography/mass selective detector/selected ion monitoring (GC/MSD/SIM). The ultrasonic extraction of US EPA (method 3550B) method and liquid-liquid extraction for sediment and soil samples were used for the analysis of BP from sediment and soil. BP was extracted with n-hexane. Organic layer was washed with 5% sodium chloride solution. 1∼2 l of the concentrated solution of organic layer was applied to GC/MSD. The retention time of BP peak was 11.10 min. Recovery (％) of BP by ultrasonication from sediment and soil samples was 96.0∼100.6％ and 40.0∼83.0％, respectively. Recovery of BP by liquid-liquid extraction was 51∼59％ in soil samples. The detection limit of BP in sediment and soil samples were determined to 0.1 ng/g.

• 대한화학회지
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• 제38권6호
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• pp.418-426
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• 1994

미국 환경청이 지정한 129종의 priority polluatants 중 40종의 비휘발성 염기/중성 유기화합물을 대상물질로 선정하였다. 분석방법으로 초음파 추출법(sonication extraction)과 Soxhlet 추출법(Soxhlet extraction)을 이용하여 토양에 있는 유기물을 추출 및 농축하여 기체크로마토그래프/질량분석기-SIM(selected ion monitoring)법으로 검출하였다. 표준물질이 첨가된 토양시료에 두 추출법을 적용하여 회수율을 구하고 정확도, 정밀도 및 검출한계를 측정하여 미량 분석의 가능성을 조사하였다.

• Archives of Pharmacal Research
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• 제27권12호
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• pp.1295-1301
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• 2004

The enantiomeric composition tests on flurbiprofen and ketoprofen present in patch products and in urine excretions following patch applications were performed as diastereomeric (R)-(+)- 1-phenylethylamides by achiral gas chromatography and by gas chromatography-mass spectrometry in selected ion monitoring mode. The method for determination of (R)- and (S)-enantiomers in the range from 0.1 to 5.0 ${\mu}$g was linear (r ${\ge}$ 0.9996) with acceptable precision (% RSD ${\le}$5.2) and accuracy (% RE = 0.6 ~ -2.4). The enantiomeric compositions of flurbiprofen in one patch product and of ketoprofen in five different products were identified to be racemic with relatively good precision (${\le}$ 6.4%). The urinary excretion level of (R)-flurbiprofen was two times higher than its antipode, while the comparable excretion levels of (R)- and (S)-enantiomers for ketoprofen were observed.

• 대한화학회지
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• 제38권3호
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• pp.246-253
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• 1994

미국 환경청이 지정한 129종의 priority pollutants 중 11종의 비휘발성 산성 유기화합물을 대상물질로 선정하여 토양시료 중의 극미량 분석방법을 연구하였다. 분석방법으로 기체크로토그래프/질량분석기- SIM(selected ion monitoring)법을 검출방법으로 정하고, 토양시료의 추출 및 농축방법으로 사용한 초음파 추출법(sonication extraction)과 Soxhlet(Soxhlet extraction)을 비교 연구하였다. 각 화합물의 회수율, 상대표준편차 및 method detection limit를 측정하여 EPA분석법을 대체할 수 있는지의 가능성을 조사하였다.

• Applied Biological Chemistry
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• 제28권2호
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• pp.82-87
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• 1985

GC-SIM분석법에 의한 GA의 동정 및 정량분석에 대한 정확성과 정출감도의 향상을 목적으로, 29종의 GA를 Me-TMS와 TMS-TMS유도체를 만들고, GC-MS에 의해 이들 유도체의 mass spectra를 측정하였으며, GC-SIM분석에 있어서 Me-TMS유도체와 TMS-TMS유도체의 장단점에 대해 검토하였다.