• Environmental Analysis Health and Toxicology
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• v.20 no.1
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• pp.47-55
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• 2005

본 연구는 GC/MS를 이용하여 수질, 토양 및 저질 시료 중의 benzo(a)pyrene(BaP)을 분석하는 방법을 확립하고자 하였다. BaP은 수질 시료(100mL)에서 n-hexane으로 추출하였으며, 토양 및 저질 시료(l0g) 에서는 먼저 메탄올로 추출한 후 hexane으로 다시 추출하여 농축시켜 분석하였다. 수질 시료 중의 BaP 회수율은 94.8% 이상이었으며 토양에서의 회수율은 약 93％를 보였고 재현성은 10.49% 이하였다. 검정 곡선은 상관계수(R²)값이 수질과 토양 모두에서 0.996 이상의 좋은 직선성을 보여주었다. 토양 시료의 경우 35지역 중 6지역의 토양에서 0.5～223.5㎍/kg의 농도 범위로 BaP가 검출되었으며 수질과 저질 시료에서는 모든 지역에서 검출한계 이하로 나타났다. 이 분석방법은 환경 중에 미량으로 존재하는 BaP의 분석과 모니터링에 유용하게 사용할 수 있는 적합한 방법이라 사료된다.

• Journal of Environmental Science International
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• v.11 no.4
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• pp.367-373
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• 2002

The polycyclic aromatic hydrocarbons(PAHs) content in sewage sludge was determined by gas chromatography linked to ion trap mass spectrometry(GC/ITMS) with five deuterated PAHs as internal standards. The minimum detection limit was from 1.66 to 7.14 pg for individual PAH by GC/ITMS. For determining total PAHs(∑PAH) in sewage sludge 84 samples from 74 waste water treatment plants in whole country were analyzed. The average content of ∑PAH far whole samples was 3,289$\pm$3,098 $\mu\textrm{g}$/kg, and ranged from 142 to maximum 20,102 $\mu\textrm{g}$/kg. According to the number of population of the city, the areas were classified as five regions, ie. big, large, middle, small, and rural area in which the waste water treated plants were grown. The contents of PAHs were 4,689$\pm$5,503, 5,839$\pm$6,401, 3,725$\pm$2,053, 2,237$\pm$2,069, and 2,475$\pm$1,489 $\mu\textrm{g}$/kg, in big, large, middle, small, and rural area, respectively.

• Journal of Microbiology and Biotechnology
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• v.31 no.1
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• pp.70-78
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• 2021

Identifying the extracellular metabolites of microorganisms in fresh vegetables is industrially useful for assessing the quality of processed foods. Pectobacterium carotovorum subsp. carotovorum (PCC) is a plant pathogenic bacterium that causes soft rot disease in cabbages. This microbial species in plant tissues can emit specific volatile molecules with odors that are characteristic of the host cell tissues and PCC species. In this study, we used headspace solid-phase microextraction followed by gas chromatography coupled with mass spectrometry (HS-SPME-GC-MS) to identify volatile compounds (VCs) in PCC-inoculated cabbage at different storage temperatures. HS-SPME-GC-MS allowed for recognition of extracellular metabolites in PCC-infected cabbages by identifying specific volatile metabolic markers. We identified 4-ethyl-5-methylthiazole and 3-butenyl isothiocyanate as markers of fresh cabbages, whereas 2,3-butanediol and ethyl acetate were identified as markers of soft rot in PCC-infected cabbages. These analytical results demonstrate a suitable approach for establishing non-destructive plant pathogen-diagnosis techniques as alternatives to standard methods, within the framework of developing rapid and efficient analytical techniques for monitoring plant-borne bacterial pathogens. Moreover, our techniques could have promising applications in managing the freshness and quality control of cabbages.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1116-1123
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• 2021

Oil spilled in seawater undergoes physical and chemical changes as well as biological degradation through various weathering processes, such as evaporation, diffusion, dispersion, emulsification, dissolution, oxidation, and sedimentation. Evaporation is one of the most immediate and prompt weathering processes, and it has the greatest influence on majority of pollutants. In this study, the evaporation characteristics of different oil samples were studied; the volatilization characteristics of gasoline, kerosene, and diesel were compared at average seawater (25 ℃) and near-equator (35 ℃) temperatures. The oil samples were pre-treated and then collected at regular intervals. Gas chromatography-mass spectrometry analysis was performed, and the changes in the amount of the hydrocarbons were calculated.

• Analytical Science and Technology
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• v.36 no.5
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• pp.205-215
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• 2023

In the present study, an analytical method was proposed for detecting trifluralin in aquatic products at trace concentrations. The method employed QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) and gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) as the sample preparation and measurement, respectively. The effect of the aqueous phase volume used in the QuEChERS was demonstrated, and the ratio of 10:10 (mL) between water and acetonitrile phase was used for 5 g of sample. Besides, dSPE using C18 and primary-secondary amine (PSA) was applied to remove the potential interferences from the food matrices, indicating no remarkable analyte loss. The linear range was built up from 0.50 ㎍ L^-1 to 3.0 ㎍ L^-1 (R² = 0.9993). Other criteria, i.e., repeatability (RSD_r = 0.86-1.96 %), reproducibility (RSD_R = 1.09-2.01 %), and recovery (over 90 %), were in accordance with Appendix F of AOAC (2016) for method performance. Although no trifluralin was detected for the commercial samples (fish, shrimp, and breaded shrimp), the spiked samples performed favorable recoveries and precision.

• Mass Spectrometry Letters
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• v.3 no.2
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• pp.43-46
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• 2012

In this study, comprehensive two dimension gas chromatography (2D GC-MS) and 15 T Fourier transform ion cyclotron resonance mass spectrometry (15T FT-ICR MS) connected to atmospheric pressure photo ionization (APPI) have been combined to obtain detailed chemical composition of a diesel oil sample. With 2D GC-MS, compounds with aliphatic alkyl, saturated cyclic ring(s), and one aromatic ring structures were mainly identified. Sensitivity toward aromatic compounds with more than two aromatic rings was low with 2D GC-MS. In contrast, aromatic compounds containing up to four benzene rings were identified by APPI FT-ICR MS. Relatively smaller abundance of cyclic ring compounds were found but no aliphatic alkyl compounds were observed by APPI FT-ICR MS. The data presented in this study clearly shows that 2D GC-MS and 15T FT-ICR MS provides different aspect of an oil sample and hence they have to be considered as complementary techniques to each other for more complete understanding of oil samples.

• Journal of Integrative Natural Science
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• v.11 no.3
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• pp.161-164
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• 2018

Over the past decade, mass spectrometry-based metabolomics, especially two dimensional gas chromatography mass spectrometry (GCxGC/TOF-MS), has become a key analytical tool for metabolomics data because of its sensitivity and ability to analyze complex biological or biochemical sample. However, the need to reduce variations within/between experiments has been reported and methodological developments to overcome such problem has long been a critical issue. Along with methodological developments, developing reasonable performance measure has also been studied. Following four numerical measures have been typically used for comparison: sensitivity, specificity, receiver operating characteristic (ROC) curves, and positive predictive value (PPV). However, more recently, such measures are replaced with F1 score in many fields including metabolomics area without any carefulness of its validity. Thus, we want to investigate the validity of F1 score on two examples, with the goal of raising the awareness in choosing appropriate performance comparison measure. We noticed that F1 score itself, as a performance measure, was not good enough. Accordingly, we suggest that F1 score be supplemented with other performance measure such as specificity to improve its validity.

• The Korean Journal of Food And Nutrition
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• v.12 no.2
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• pp.191-191
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• 1999

A Purge & Trap Concentrator was used to analyze various volatile organic compounds(VOCs) in wat-er. The object of this study was to observe the purge efficiency of 40 VOCs in water according to the change of parameters (purge time drypurge time sample temperature) and to determine the optimum condition for VOCs using the purge & Trap concentrator interfaced with a narrow capillary connected to a gas chromatography/mass spectrometry. The optimum condition of purge and trap is as follows: purge time at 11min drypurge time at 5min sample temperature at 6$0^{\circ}C$ at constant purge flow (40mol/min) constant desorption flow(20ml/min) desorption temperature(2$25^{\circ}C$) and desorption time (1min) At this analytical condition the detection limits of VOCs was in the range of 0.1~0.5$\mu$g/ml and the purge efficiency of each compound was over 70%.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.985-987
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• 2008

Parathion is an organophosphate pesticide being legally applied for the purpose of agriculture and is being manufactured in Korea. A gas chromatography/mass spectrometric method was developed for the determination of parathion urinary metabolite, p-nitrophenol. p-Nitrophenol was extracted from weak acidic urine, and then measured by gas chromatography-mass spectrometry (selected ion monitoring). The recovery of pnitrophenol in the overall procedure was 88.2%. The detection limit of the assay was 1.0 $\mu$ g/L based upon assayed urine of 2.0 mL. The method was applied to the determination of p-nitrophenol in urine of workers of a parathion industry. Spot urines of workers of a parathion industry were sampled at the end of shift and pnitrophenol was analyzed using above developed method. p-Nitrophenol could be detected in all of the urine samples at concentrations varying from 3.0 to 681 $\mu$ g/L.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.806-808
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• 2004

A gas chromatography/mass spectrometric assay method has been developed for the simultaneous determination of icing inhibitors, ethylene glycol monomethyl ether and diethylene glycol monomethyl ether in ground water contaminated with JP-8. Ethylene glycol monobutyl ether and ethylene glycol monoethyl ether were used as the internal standard and surrogate, respectively. 100 mL of ground water was extracted twice with 20 mL of methylene chloride. The extract was concentrated to dryness, dissolved with 100 ${\mu}$L of methanol and analyzed by GC-MS (SIM). The use of an Innowax column gave the peaks good chromatographic properties, and the extraction of these compounds from samples gave recoveries of about 50% with small variations. The method detection limits of the target compounds were in a range of 0.5-0.8 ng/mL in ground water.