• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.173-176
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• 2006

Pyrolysis-gas chromatography (Py-GC) in the presence of organic alkali of tetrabutylammonium hydroxide (TBAH) was applied to characterize the polyphenol fragments with a carbonyl group causing different magnitude of photo-yellowing in chemithermomechanical pulp (CTMP) papers. Two different origin of CTMP papers prepared from different individuals of Eucalyptus globulus trees showing high and low yellowing after photo-irradiation was compared before photo-irradiation. As a result, 7 peaks assigned to a series of phenol compounds with a carbonyl group, derived mainly from lignin, gave significant amount of phenol compounds with a carbonyl group for the paper sample of latent high yellowing, i.e., butoxy-and syringaldehyde, butoxy-and syringylacetone, butoxy-acetoguaiacone, butoxy-acetosyringone, butoxy-acetoethylsyringone, 3-methoxy-4-butoxy butyl ester, and 3,5-dimethoxy-4-butoxy butyl ester, using Py-GC/mass spectrometry (MS). The Py-GC method combined with TBAH successfully characterized polyphenol fragments with a carbonyl group causing differ high photo-yellowing in CTMP papers using a microgram order of samples.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.196-200
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• 2003

A gas chromatography/mass spectrometric assay method was developed for the simultaneous determination of ethylene glycol monomethyl ether (EGME) and diethylene glycol monomethyl ether (DEGME) in spilled aviation fuels. Ethylene glycol monobutyl ether (EGBE) and ethylene glycol monoethyl ether (EGEE) were used as internal standard and surrogate, respectively. The sample preparation consists of back-extraction with 7 mL of methylene chloride after extraction of 50 mL of fuel with 2 mL of water. The extract was concentrated to dryness and dissolved with 100L of methanol and analyzed by CC-MS (SIM). The peaks had good chromatographic properties by using semi-polar column and the extraction of these compounds from fuel also gave high recoveries of 75 and 85 % with small variations for EGME and DEGME, respectively. Method detection limits were 1.3 ng/mL for EGME and 1.0 ng/mL for DEGME in spilled fuel. The method may be useful for fuel-type differentiation between kerosene and JP-8, which may originate from the storage tank.

• Korean Journal of Environmental Agriculture
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• v.36 no.4
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• pp.269-278
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• 2017

BACKGROUND: The objective of this study was to evaluate screening method of residual multi pesticides in dead birds by Orbitrap high resolution mass spectrometry (HRMS) to identify the cause of death for birds. METHODS AND RESULTS: Extraction and clean-up method of residual pesticides in liver of dead birds was used QuEChERS (Quick Easy Cheap Effective Rugged and Safe) and method validations was conducted using liquid chromatography and gas chroamtography with triple-quadrupole mass spectrometer (LC/MS/MS and GC/MS/MS) Also, we were evaluated screening method for the determination of residual pesticides in liver of dead birds by LC and GC Orbitrap Mass Spectrometry. Results of method validations, Correlation coefficients of the matrix matched calibration curves were >0.978, and the method detection limits (MDLs) and limits of quantitation (LOQ) were 2.8~72.1 ng/g (18.4 ng/g on average) and 9.0~230 ng/g (58.5 ng/g on average). The accuracy ranged from 69.1%to 130% (103% on average), and the precision values were less than 14.8%(3.8%on average). The screening of residual pesticides in liver of dead birds by LC and GC Orbitrap HRMS was detected monocrotophos, carbofuran, carbosulfan, deltametrin, benfuracarb, carbofuran, phosphamidon, prochloraz in investigated samples. CONCLUSION: This results showed that accurate mass were extraction of residual pesticides in dead birds by Orbitrap HRMS. It suggested that this screening method is applicable to the residual pesticide analysis for the cause of death as a main tool.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.171-176
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• 1992

Volatile flavor components of Codonopsis lanceolata were extracted by gas co-distillation (GCD), solvent extraction/fractionation (SEF), and headspace sampling (HSS) methods. The extracts were analyzed by dual-capillary gas chromatography-retention index (GC-RI) and gas chromatography-mass spectrometry(GC-MS). The two extracts prepared by SEF and HSS gave more similar fragrance to the Codonopsis lanceolata than the GCD extract. The GC profiles of the SEF and HSS extracts were similar to each other except for differences in peak areas. The extract prepared by SEF gave a sweet note while the extract prepared by HSS gave a green note. The GCD extract began to give a burnt note of herb medicine with prolonged distillation. Rapid extraction of flavor components from Codonopsis lanceolata was possible in several short steps by SEF and HSS methods compared to GCD. GC-MS and GC-RI were used for peak identification. GC-RI was more effective for identification of isomers, and polar FFAP column was more suitable for identification of polar compounds. From Codonopsis lanceolata we identified 35 volatile flavor constituents, 24 of which have not been previously reported by simultaneous distillation extraction method $^{(5)}$. trans-2-Hexanal, cis-3-hexen-1-ol, trans-2-hexen-1-ol, and hexanol were considered key components of the green note and 1-octen-3-ol, the component of the fresh note. Esters, including amyl propionate, seem to be responsible for the sweet note particular to Codonopsis lanceolata.

• Toxicological Research
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• v.26 no.2
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• pp.149-155
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• 2010

The pesticide trichlorfon is readily degraded under experimental conditions to dichlorvos. A method has therefore been developed by which residues of trichlorfon in milk are determined as dichlorvos, using gas chromatography with ${\mu}$-electron capture detection. The identification of dichlorvos was confirmed by mass spectrometry. Milk was extracted with acetonitrile followed by centrifugation, freezing lipid filtration, and partitioning into dichloromethane. The residue after partitioning of dichloromethane was dissolved in ethyl acetate for gas chromatography. Recovery concentration was determined at 0.5, 1.0, and 2.0 of times the maximum permitted residue limits (MRLs) for trichlorfon in milk. The average recoveries (n = 6) ranged from 92.4 to 103.6%. The repeatability of the measurements was expressed as relative standard deviations (RSDs) ranging from 3.6%, to 6.7%. Limit of detection (LOD) and limit of quantification (LOQ) were 3.7 and $11.1{\mu}g/l$, respectively. The accuracy and precision (expressed as RSD) were estimated at concentrations from 25 to $250{\mu}g/l$. The intra- and inter-day accuracy (n = 6) ranged from 89.2% to 91% and 91.3% to 96.3%, respectively. The intra- and inter-day precisions were lower than 8%. The developed method was applied to determine trichlorfon in real samples collected from the seven major cities in the Republic of Korea. No residual trichlorfon was detected in any samples.

• Advances in environmental research
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• v.4 no.1
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• pp.39-48
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• 2015

Bisphenol A is widely used in plastic and other industrial consumer products. Release of bisphenol A and its analogues into the aquatic environment during manufacture, use and disposal has been a great scientific and public concern due to their toxicity and endocrine disrupting effects on aquatic wildlife and even human beings. More recent studies have shown that these alkylphenols may affect the molting processes and survival of crustacean species such as American lobster, crab and shrimp. In this study, we have developed gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometric (GC-MS) methods for the determination of bisphenol A and its analogues in shrimp Macrobrachium rosenbergii, blue crab Callinectes sapidus and American lobster Homarus americanus samples. Bisphenol A, 2,4-bis-(dimethylbenzyl)phenol and 4-cumylphenol were found in shrimp in the concentration ranges of 0.67-5.51, 0.36-1.61, and < LOD (the limit of detection)-1.96 ng/g (wet weight), and in crab of 0.10-0.44, 0.13-0.62, and 0.26-0.58 ng/g (wet weight), respectively. In lobster tissue samples, bisphenol A, 2-t-butyl-4-(dimethylbenzyl)phenol, 2,6-bis-(t-butyl)-4-(dimethylbenzyl)phenol, 2,4-bis-(dimethybenzyl)phenol, 2,4-bis-(dimethylbenzyl)-6-t-butylphenol and 4-cumylphenol were determined at the concentration ranges of 4.48-7.01, 1.23-2.63, 2.71-9.10, 0.35-0.91, 0.64-3.25, and 0.44-1.00 ng/g (wet weight), respectively. At these concentration levels, BPA and its analogs may interfere the reproduction and development of crustaceans, such as larval survival, molting, metamorphosis and shell hardening.

• Analytical Science and Technology
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• v.23 no.4
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• pp.395-404
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• 2010

A multi-residual method using gas chromatography coupled with mass spectrometry (GC/MS/ MS) was developed for the analysis of 105 pesticides. This method was tested on lemons, beans and other vegetables. The pretreatment of these pesticides was performed by liquid-liquid partition followed by cleanup with solid phase extraction cartridge (SPE Florisil), after acetonitrile extraction from matrices and sodium chloride (15 g) addition. The recovery ranged from 71.1% to 126.0% except for azinphosmethyl, famoxadone, fenamidone, flufenoxuron and triadimefon in lemons and from 72.5% to 124.5% in bean. In lemon, the limit of detection (LOD) and limit of quantification (LOQ) were 0.001~150 ng/ mL and 0.004~500 ng/mL, respectively.

• Journal of the Korean Society of Tobacco Science
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• v.36 no.1
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• pp.26-33
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• 2014

Simultaneous determination of crop protection agents(CPAs) in food are done with multi-residue methods, which are composed of sample clean-up, concentration, chromatographic separation and detection. Stir Bar Sorptive Extraction(SBSE) technique is used for sample preparation of various analytes in several fields. The aim of this study was to develop a sensitive and fast method based on SBSE followed by thermal desorption - gas chromatography - mass spectrometry(TD - GC/MS) to determine CPAs in tobacco sample. For the analysis of tobacco sample prior to the SBSE method, solvent extraction or ultrasound-assisted solvent extraction was performed. methanol was used as the extraction solvent. The extract was then diluted with water. Finally, the sample was subjected to SBSE. A method for fast screening of crop protection agents in tobacco using SBSE-TD - GC/MS has been developed. About 17 CPAs including organochlorine, organophosphorous and others were identified and quantified. This method showed good linearity and high sensitivity for most of the target CPAs. The method was applied to the determination of CPAs at ng/mL levels in tobacco sample. This method is simple, rapid and may be applied in detection of other components.

• The Korean Journal of Community Living Science
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• v.24 no.2
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• pp.243-249
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• 2013

Identification of coating film species from ancient coating materials is needed to maintaine their surfaces without loss of their original beauty for a long time and understand the historical background of manufacturing techniques. A pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was applied to identify the origine of films in ancient coating materials. The pyrolysis products, which reflect the source from which they originate were detected distinctively at $500^{\circ}C$. This is a rapid technique that does not require large amounts of sample or any sample preparation. Sesquiterpenes are a class of terpenes that consist of three isoprene units were identified as cadienes, selinenes, cubebenes from the raw material of dendropanax morbifera. On the other hand, alkanes(tetra~heptadecanes), alkenes (tri~heptadecenes), allkyphenols, catechols and fatty acids were detected from the raw material of the lacquer film. Based on these results, the origine of historic coatings artifacts was identified using py-GC/MS by comparison with their pyrolysis products.

• The Korean Journal of Community Living Science
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• v.23 no.2
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• pp.199-206
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• 2012

In order to evaluate the aroma compounds in Korean traditional alcoholic beverages, volatile compounds of the commercial wines, Makgeolli were analyzed and quantified using the conventional method. Eight volatile compounds including three kinds of alcohols, two kinds of organic acids and three kinds of ether were extracted by Liquid-Liquid Extraction with Dichloromethane. For the separation and quantification, Gas chromatography coupled with mass spectrometry (GC/MS) was used to analyze these compounds. Also, the separation efficiency of these compounds was performed and compared with GC column. The results of this study were as follows ; Eight kinds of volatile compounds were separated well on the HP-88 column better than on the DB-5MS column. Short chain fatty acids, butyric acid and isovaleric acid were not detected in two brands of makgeolli samples. The higher alcohols were detected in the range of 0.86~225.68 ${\mu}g/mL$ and ethyl esters were detected in the range of 0.86~225.68 ${\mu}g/mL$, respectively. There compounds are known to be associated with sensory and odorant.