• 한국환경과학회지
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• 제11권6호
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• pp.605-610
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• 2002

The absorption of benzene in nonpolar solution was studied in a laboratory-scale of bubble column varying of gas flow rates and gas-to-liquid ratios. A bubble column had a 0.8∼l$\times$10$\^$-3/ m$^3$ total volume (height 1500 mm, diameter 50 mm). Solution analysis was performed by GC-FID and GC-MSD. The objectives of this research were to select the best absorption fluid and to evaluate the mass transfer characteristics under specific conditions of each absorption. The results of this research were follow as: First, the heat transfer fluid is more efficient than the other nonpolar solution in removing VOC. Second, The benzene removal efficiency improved according to an increasing rate of gas flow. Also, volumetric mass transfer rate of column can be enhanced by increasing gas flow rate. Finally, the relation of gas flow rates, liquid amount, and volumetric mass transfer coefficient was obtained as follows. K$\_$y/a: 0.5906(V$\_$g//L)$\^$0.7611/ The following correlation of mass transfer coefficient and efficiency was proposed. v= 0.06078 K$\_$y/a$\^$0.2444/.

• 약학회지
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• 제40권2호
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• pp.141-148
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• 1996

GC/MS analysis of 27 controlled pesticides in herbal drugs was studied. Selected ion monitoring(sim) technique was applied to increase the GC/MS sensitivity. Typical peaks in th e mass spectrum of each pesticides were selected as quantitation, comfirmation or alternate ion. Twenty seven pesticides were divided into five groups according to their retention time and the peaks for SIM were programmed accordingly. The combination of two ionization methods, electron impact(EI)-SIM-MS and negative ion chemical ionization(NCI)-SIM-MS, were well-fitted for the detection, confirmation and quantitation of multiclass residual pesticides in herbal drugs.

• Journal of Ginseng Research
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• 제20권3호
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• pp.284-290
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• 1996

To Identify phenolic components known to exist in Korean ginseng (Panax ginseng C.A. Meyer) by GC/MS, three derivatization methods were employed for their analyses. First, phenolic components in ether soluble acidic fraction prepared from Korean red ginseng powder were taimethylsilylated. Secondly, phenolic acids in the same fraction were esterified with diazomethane followed by trlmethylsilylation. Thirdly, acidic components in ginseng powder were extracted and esterified concurrently by methanolic sulfuric acid, followed by fractionation of phenolic components with Silica Sep-Paka and trimethylsilylatlon. All phenolic components found in ginseng except gen tisic acid were identified by retention times and mass spectrums of standards. Besides, 5 phenolic components including salicyl alcohol and 1-H-indole-2-carboxylic acid were first identified from Korea an red ginseng by GC/MS.

• 한국화재소방학회논문지
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• 제26권6호
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• pp.7-14
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• 2012

본 연구에서는 화재현장에서 유류와 관련되어 실화나 방화의 매개체로 사용되어 화재가 발생했을 때 석유류의 정확한 분석기법을 개발하기 위하여 발화지점 주변의 온도분포, 연소되고 남은 물질의 흔적과 GC/MS 분석으로 물질의 종류를 확인하는 것을 가연성 고체와 비교해서 실험하였다. 연구결과 천장에 도달하는 온도는 휘발유와 시너는 점화되자마자 불꽃이 생성되어 천장의 온도가 매우 빠르게 상승하여 그곳에 물질이 있을 경우 2차 화재발생이 전개될 것으로 나타났다. 연소된 후에 바닥에는 가연성 고체와 유류가 상이한 특징적인 패턴을 형성하였다. 연소된 장판은 탄화수소계열이지만 가스검지관을 통해 반응을 확인한 결과 가연성 고체는 아무런 반응을 띠지 않았으나 유류는 즉시 반응을 하였고 그 연소물질을 7일이 경과된 후에 GC/MS로 분석한 결과 유류의 존재를 확인할 수 있었다. 화재조사가 복잡한 과정이지만 물질의 특성을 통한 세밀한 조사는 유류화재를 입증하는 데 중요하고 GC/MS분석기기를 통해 실체를 확인하는 과정이 요구된다.

• 분석과학
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• 제33권1호
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• pp.23-32
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• 2020

Methamphetamine (MA) is the most common and available drug of abuse in Korea and its primary metabolite is amphetamine (AP). Detection of AP derivatives, such as MA, AP, phentermine (PT), MDA, MDMA, and MDEA by the use of immunoassay screening is not reliable and accurate due to cross-reactivity and insufficient specificity/sensitivity. Therefore, the analytical process accepted by most urine drug-testing programs employs the two-step method with an initial screening test followed by a more specific confirmatory test if the specimen screens positive. In this study, a gas chromatography-mass spectrometric (GC-MS) method was developed and validated for confirmation of MA and AP in human urine. Urine sample (500 µL) was added with N-isopropylbenzylamine as internal standard and ethyl chloroformate as a derivatization reagent, and then extracted with 200 µL of ethyl acetate. Extracted samples were analysed with GC-MS in the SIM/ Scan mode, which were screened by Cobas c311 analyzer (Roche/Hitachi) to evaluate the efficiency as well as the compatibility of the GC-MS method. Qualitative method validation requirements for selectivity, limit of detection (LOD), precision, accuracy, and specificity/sensitivity were examined. These parameters were estimated on the basis of the most intense and characteristic ions in mass spectra of target compounds. Precision and accuracy were less than 5.2 % (RSD) and ±14.0 % (bias), respectively. The LODs were 3 ng/mL for MA and 1.5 ng/mL for AP. At the screening immunoassay had a sensitivity of 100% and a specificity of 95.1 % versus GC-MS for confirmatory testing. The applicability of the method was tested by the analysis of spiked urine and abusers' urine samples.

• 한국식품조리과학회지
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• 제14권5호
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• pp.541-546
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• 1998

자생 누룩치의 휘발성 향미성분을 연속수증기증류 장치로 추출한 후 GC, GC/MS로 분석하여 31개의 휘발성 향미성분이 확인되었는데, 탄화수소류가 15종으로 전체 peak area의 64.98%를 차지하였고 알데히드류 4종 9.54%, 케톤류 1종 0.16%, 알코올류 5종 7.65%, 에스테르류 2종 2.06%, 산류 3종 2.0% 및 옥사이드류 1종 2.75%로 이루어져 있었다. 탄화수소류 중 mono-terpenes은 peak area 0.54% 및 sesquiterpenes은 52.11% 를 차치하였다. 누룩치의 주요 휘발성 향미성분은 sesquiterpenes인 (Z)-$\beta$-farnesene, (Z, E)-$\alpha$-farnesene 및 farnesene으로 사료된다. Headspace법에 의하여 신선한 누룩치의 휘발성 향미성분을 포집하여 전자코로 분석한 결과, 알코올류와 같은 극성화합물이 가장 많이 감지되었고 알데히드류, 탄화수소류 순서로 감지되었다. 또한 건조된 누룩치는 신선한 시료와 유사한 향미성분 패턴을 보였으나, 각 sensor의 저항치가 현저히 낮아 건조된 시료의 휘발성 향미성분이 비교적 적음을 확인하였다.

• 한국식품위생안전성학회지
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• 제23권3호
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• pp.191-197
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• 2008

희아리 고춧가루에 특징적인 표지자를 찾기 위하여 GC/MASS분석, 고춧가루 표면 분석, 미생물 계수법을 수행하였다. 희아리 고춧가루는 정상 고춧가루에서는 발견되지 않은 분자량 204의 1,2,3,5,6,7,8,$8\alpha$-octahydro-1,$8\alpha$-dimethyl-7-(1-methylethenyl)-naphthalene과, 분자량 204의 2-isopropenyl-$4\alpha$,8-dimethyl-1,2,3,4,$4\alpha$,5,6,$8\alpha$-octahydronaphthalene을 함유하고 있었다. 그러나 희아리 시료간의 함량 차이가 10배 이상으로 컸고, 낮은 함량을 지닌 희아리로 불량고춧가루를 제조 시 검출 기준 이하로 떨어지는 문제점이 있었다. 희아리의 전자 현미경 사진은 정상고추의 매끈한 표면과는 다르게 가루 표면이 거칠고 수많은 미생물이 자라고 있음을 보였다. 한편 희아리는 10%(w/w) 희아리가 혼합된 불량고춧가루 경우에도 정상고춧가루와 확실히 구분되는 세균 및 효모/곰팡이 균수의 증가를 나타냈다. 결과적으로 이 3가지 기술에 의한 정성 정량적인 결과를 상호 보완적으로 분석하는 경우 불량고춧가루 판정은 가능하다고 생각된다.

• Biomolecules & Therapeutics
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• 제1권2호
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• pp.143-150
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• 1993

The metabolic profile of triprolidine, 2-[(4-methylphenyl)-3-(1-pyrrolidinyl-1-propenyl)] pyridine, was determined. Urinary extracts obtained with enzyme hydrolysis were derivatized with MSTFA/TMSCl (N-methyl-N-trimethylsilyl trifluoroacetamide/trimethylchlorosilane) and analyzed by GC/MSD. In human urine, which were obtained after the oral administration with triprolidine, hydroxymethyltriprolidine, triprolidine carboxylic acid, oxotriprolidine carboxylic acid and unchanged triprolidine were detected. The maximum urinary excretion rate of triprolidine and hydroxymethyltriprolidine which were extracted from human urine was at 2 to 4 hours after the drug administration. Triprolidine and hydroxymethyl triprolidine were identified by comparison with authentic standards In chromatographic and mass spectral properties. Triprolidine carboxylic acid was detected as a major metabolite of its metabolites in the urine. Oxotriprolidine carboxylic acid and triprolidine carboxylic acid were tentatively identified by the interpretation of its mass spectral patterns. These data suggest that in human, hydroxylation of either the benzyl or pyrrolidine ring can occur during triprolidine elimination.

• 천문학회보
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• 제39권1호
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• pp.58.2-58.2
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• 2014

The Arches cluster is a young (2-4 Myr), compact (~1 pc), and massive (${\sim}2{\times}10^4M_{\odot}$) star cluster located ~30 pc away from the Galactic center (GC) in projection. Being exposed to the extreme environment of the GC such as elevated temperature and turbulent velocities in the molecular clouds, strong magnetic fields, and larger tidal forces, the Arches cluster is an excellent target for understanding the effects of star-forming environment on the initial mass function (IMF) of the star cluster. However, resolving stars fainter than ~1 $M_{\odot}$ in the Arches cluster partially will have to wait until an extremely large telescope with adaptive optics in the infrared is available. Here we devise a new method to estimate the shape of the low-end mass function where the individual stars are not resolved, and apply it to the Arches cluster. This method involves histograms of pixel intensities in the observed images. We find that the initial mass function of the Arches cluster should not be too different from that for the Galactic disk such as the Kroupa IMF.

• 한국산업보건학회지
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• 제31권1호
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• pp.1-12
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• 2021

Objective: The purpose of this study was to contribute to the prevention of occupational diseases through the development of an automatic analysis program for evaluating workers' exposure to hazardous chemical substances. Methods: The authors selected chemical substances that caused occupational disease in Korea and chemical substances that are frequently used in industrial sites as target substances for a GC-MS automatic analysis program. The target substances are organic compounds which can be measured by a passive sampler. The automatic analysis program was studied using various raw data obtained from GC-MS analysis for the target substances. Results: A total of 48 organic compounds that can be measured with a passive sampler were selected as target substances for the GC-MS automatic analysis program. The selected compounds included substances that caused occupational disease, substances related to C1 and D1 in special health examinations, and substances for which work environment measurements have been frequently conducted. The GC-MS automatic analysis program was developed by combining information mainly on retention time and mass spectrum. The GC-MS automatic analysis program is designed to analyze unknown samples by comparing the mass spectrum and retention time of the samples to those of reference materials. To evaluate the stability of the program, samples at about the 30-50% level of OELs were prepared and analyzed with the GC-MS automatic analysis program, resulting in stable results for all 48 organic compounds. Conclusion: An automatic analysis program for a total of 48 organic compounds was developed using a GC-MS system that can analyze organic compounds. Unknown samples that contain the 48 organic compounds can be automatically analyzed by the developed program. It is anticipated that it can contribute to the prevention of occupational diseases through an GC-MS automatic analysis program that can quickly provide workers with information on exposure to chemical substances.