• Applied Biological Chemistry
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• v.31 no.1
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• pp.106-113
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• 1988

The rice lamina inclination test indicated the presence of brassinosteroid-like active substances in immature Vicia faba seeds. Two of these were identified as castasterone and brassinolide by GC/MS and GC/SIM, respectively. Another active principle was identified as methyl 4-chloroindole-3-acetate by GC/MS and HPLC.

• Analytical Science and Technology
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• v.21 no.5
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• pp.403-411
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• 2008

Dimethyldibutyltetradecylmalonamide (DMDBTDMA) extractant was used in a solvent extraction process for a radioactive liquid waste treatment. For the study of radiolysis phenomena, DMDBTDMA was synthesized and the degradation compounds (n-methylbutylamine, tetradecane, 1-tetradecanol) in the DMDBTDMA extractant, irradiated with $^{60}Co$ gamma ray, were identified and determined as radiolysis products by a Fourier transform infrared (FT-IR), gas chromatograph/mass spectrometer (GC/MS) analysis and GC/MS with selected ion monitoring (SIM) mode. Retention behavior of n-methylbutylamine, n-dodecane, tetradecane and 1-tetradecanol in the total ion chromatogram with the standard materials and n-dodecane as the internal standard (ISTD) were 2.35 min., 8.83 min., 10.68 min. and 12.75 min., respectively. In the case of tetradecane, there was a linear relationship between the concentration of the tetradecane and the absorbed dose of the ${\gamma}$-ray irradiated DMDBTDMA.

• Analytical Science and Technology
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• v.20 no.2
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• pp.91-108
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• 2007

This study was investigated both the Korean official soil test method and the international various methods for PCBs in soil sample. The analytical guideline of PCBs in contaminated soil were proposed based on the official soil test methods by discussing the extraction, column cleanup, instrumental conditions, quantification methods of peak matching and individual isomers. The total 28 soil samples were selected by consideration of PCBs-contamination, land use etc., and then analyzed using gas chromatography/electron capture detection (GC/ECD) and gas chromatography/mass spectrometry(GC/MS). In this study, the PCBs were not detected as peak matching method using GC/ECD, but PCBs detected $0.002{\sim}0.487{\mu}g/kg$ using GC/MS in background concentrations.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.11
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• pp.764-770
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• 2014

This study assessed analysis of N-nitrosamines by separation, identification, and quantification using a gas chromatography (GC) mass spectrometer (MS) with electron impact (EI) mode. Samples were pretreated by a automated solid phase extraction (SPE) and a nitrogen concentration technique to detect low concentration ranges. The analysis results by EI-GC/MS (SIM) and EI-GC/MS/MS (MRM) on standard samples with no pretreatment exhibited similar results. On the other hand, the analysis of pretreated samples at low concentrations (i.e. ng/L levels) were not reliable with a EI-GC/MS due to the interferences from impurity peaks. The method detection limits of eight (8) N-nitrosamines by EI-GC/MS/MS analysis ranged from 0.76 to 2.09 ng/L, and the limits of quantification ranged from 2.41 to 6.65 ng/L. The precision and accuracy of the method were evaluated using spiked samples at concentrations of 10, 20 and 100 ng/L. The precision were 1.2~13.6%, and the accuracy were 80.4~121.8%. The $R^2$ of the calibration curves were greater than 0.999. The recovery rates for various environmental samples were evaluated with a surrogate material (NDPA-$d_{14}$) and ranged 86.2~122.3%. Thus, this method can be used to determine low (ng/L) levels of N-nitrosamines in water samples.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2001.11a
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• pp.80-80
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• 2001

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.100-106
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• 2005

To obtain the optimum condition for analysis of 10 alkaloids in tobacco leaves, such as nicotine, nornicotine, anatabine, anabasine, myosmine, cotinine, 2,3'-dipyridyl, $\beta-nicotyrine,\;\beta-nornicotyrine\;and\;\beta-formylnornicotin$, 5 types of extraction method were investigated by GC-FID and GC/MS. The optimum condition of alkaloid extraction was achieved by using methanol:dichloromethane(1:3, v/v) after NaOH treatment. The use of mass selective detector (MSD) provided unambiguous nicotine related alkaloid analysis. Alkaloids in various tobacco leaves were extracted with the optimum extraction condition and quantified by GC/MS/SIM mode. Compared with concentrations of alkaloids among the various tobacco leaves, the concentration of alkaloids was generally in the order burley > flue-cured > oriental tobacco. In flue-cured tobacco leaves, the order of concentration of alkaloids was nicotine > anatabine > nornicotine > $\beta-nicotyrine\;>\;\beta-formylnornicotine\; >\;myosmine\;>\;2,3'-dipyridyl\;>\;cotinine\;>\;anabasine\;>\;\beta-nornicotyrine$. However, in the case of burley and oriental tobacco leaves, the concentration of nornicotine was higher than that of anatabine.

• Analytical Science and Technology
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• v.16 no.6
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• pp.438-442
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• 2003

The fungicides, used for grape growth and remained in the wine products from domestic and foreign countries such as vinclozolin, dichlofluanid, penconazole, procymidone were quantitatively analyzed after solid-phase extraction using a GC/MS-SIM method. The results obtained were as follows: for all the samples, the content of procymidone was in the range from 2.2 to $76.1{\mu}g/L$, recoveries 81.3-93.1 %, and standard deviation 1.4-3.4 %.

• Biomolecules & Therapeutics
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• v.15 no.4
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• pp.266-272
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• 2007

A rapid analytical method was developed to quantify very long-chain fatty acids (VLCFAs, C22:0, C24:0, C26:0) in human plasma with good sensitivity and specificity using tert-butyldimethylsilyl (TBDMS) derivatization and stable isotope GC-MS selective ion monitoring (GC-MS/SIM). Two-hundred and fifty ${\mu}L$ of plasma was fortified with deuterated stable isotope internal standards (d3-C22:0, d3-C24:0, d3-C26:0) and standard mixtures of chloroform and methanol, and then extracted with hexane and acetonitrile. To upper layer of liquid-liquid-extraction, N-(t-Butyldimethylsilyl)-N-methyltrifluoroacetamide was added and then heated to $60^{\circ}C$ for 30 min to produce the TBDMS derivatives. Derivatives of VLCFAs were analyzed by GC-MS/SIM. Calibration curves showed a linear relationship for the target compounds in the concentration range of $10^{-4}{\sim}2{\times}10^3\;{\mu}g/mL$ with the correlation coefficient ranging from 0.996 to 0.999. The limit of quantification for the plasma was $10^{-4}{\sim}2{\times}10^{-4}\;{\mu}g/mL$ (S/N=3). When applied to the plasma specimens of patients with peroxisomal disorder, X-linked adrenoleucodystropy (ALD, Mckusick 202370), the method clearly differentiated normal subjects from ALD patients. The C24:0/C22:0 and C26:0/C22:0 ratios were significantly elevated in the plasma of patients with X-linked ALD compared to normal subjects. The new developed method might be useful for a rapid and sensitive diagnosis of X-linked ALD and other peroxisomal disorders.

• Analytical Science and Technology
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• v.14 no.2
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• pp.109-114
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• 2001

The flavor-related compounds contained in tobacco were analyzed by selected ion monitoring (SIM) method using headspace SPME gas chromatography-mass spectrometry(GC-MS). Flavor-related compounds were estragole pulegone, trans-anethole, safrole, piperonal, eugenol, methyleugenol, coumarin, trans-isoeugenol, trans-methyleugenol and myristicin. More than on of the flavor-related compounds were detected in the range $0.001-1.3{\mu}g/g$ from all brands of tobacco studied. The recovery was ranged from 89.1 to 102.9% and relative standard deviation was ranged from 2.6 to 25.2%.

• Analytical Science and Technology
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• v.18 no.6
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• pp.453-459
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• 2005

Phenol compounds in water were simultaneously analyzed by extractive derivatization. Aqueous solution was controlled to pH 13 with sodium hydroxide, and then $500{\mu}L$ of benzoyl chloride was added to the solution. The solution was shaken for 15 minutes and extracted with diethyl ether and then analyzed using GC/MS-SIM. The calibration curves of phenolic compounds in the range of 0.05 to $5.0{\mu}g/mL$ showed a good linearity having the correlation coefficient of $r^2=0.9915$ and standard deviation of ${\leq}8.5%$, respectively. The recoveries by this method ware 58.4-114.0%.