• Analytical Science and Technology
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• v.18 no.6
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• pp.511-519
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• 2005

A method for determination of toluene diisocyanates (TDI) in toluene diisocynate (TDI)-based polyurethane (PUR) packing material was investigated, and also the migration of TDI to food was studied. TDI was extracted using food simulants such as n-haptane and 4% aqueous acetic acid. The determinations were performed using gas chromatography/mass spectrometry (GC/MS). One of major components for polyurethane, toluene diisocyanates, were detected in ten samples among twenty six food contact materials with the concentration range of $0.51{\sim}60.88{\mu}g/ml$. However the highest extracted amount was just 0.7% of $60.88{\mu}g/ml$ if the contact surface of food packing for extracting liquid was limited to the outer layer without exposure of the cutting edge of food packing multi-layers. The result of this study and the analysis method for TDI diisocyanate will be very useful for further study about food contact material, and the monitoring result could be used for evaluating the safety of food contact material before it is to be used for food, preservation.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.17 no.2
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• pp.39-47
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• 2017

Purpose: A sensitive gas chromatography mass spectrometry (GC-MS) method was developed for screening of fatty acid oxidation disorders. Methods: The assay utilized a simple protein precipitation with sulfosalicylic acid followed by tert-butyl dimethylsilyl (TBDMS) derivatization of hydroxyl functional group by N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA). Results: Calibration curves of spiked pooled plasma showed a linear relationship in the range of 0.01 ng -2 mg with correlation coefficient value greater than 0.98. Limits of detection (LOD) and limits of quantification (LOQ) were found in the range of 0.9-8.8 ng and 9-88 ng, respectively. Conclusion: The new developed method might be useful for a rapid, sensitive screening of inherited fatty acid oxidation disorders. In addition, the method expected to be one of the alternative method for screening newborns of metabolic disorders in the laboratories where expensive MS/MS is unavailable.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.704-708
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• 2015

For the analysis of multiple-reaction intermediates for long-chain dicarboxylic acid biotransformation, simple and reproducible methods of extraction and derivatization were developed on the basis of gas chromatography with flame ionization detector (GC-FID) instead of mass spectrometry. In the derivatization step, change of the ratio of pyridine to MSTFA from 1:3 to 9:1 resulted in higher peak intensity (p = 0.021) and reproducibility (0.6%CV) when analyzing 32 g/l ricinoleic acid (RA). Extraction of RA and ω-hydroxyundec-9-enoic acid with water containing 100 mM Tween 80 showed 90.4-99.9% relative extraction efficiency and 2-7%CV compared with those with hydrophobic ethyl acetate. In conclusion, reduction of the pyridine content and change of the extraction solvent to water with Tween 80 provided compatible derivatization and extraction methods to GC-FID-based analysis of longchain carboxylic acids.

• Journal of Environmental Health Sciences
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• v.32 no.1 s.88
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• pp.67-70
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• 2006

A gas chromatography/mass spectrometric method was developed for the determination of formaldehyde in hair. 0.3mg of hair was placed in 10ml headspace vial. 1.5mM pentafluorophenylhydrazine solution (pH 2) in 0.03 M phosphoric acid and $20\;{\mu}l$ of 500 mg/l $acetone-d_6$ as internal standard were added in vial and sealed tightly with cap. The solution was heated for 30 min at $90^{\circ}C$ in heating block. The extraction, the derivatization and the evaporation were performed simultaneously. After heating of the solution, 0.5 ml of headspace was taken up and analyzed by gas chromatography-mass spectrometry (GC-MS). Low limit of detection (LaD) and Low limit of quantitation (LOQ) of formaldehyde were 0.5 and 1.5 ng/g, respectively. The method was used to analyze formaldehyde in rat hair after oral exposure. The developed method may be valuable to be used to analyze formaldehyde in human hair.

• Journal of Food Hygiene and Safety
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• v.8 no.1
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• pp.17-23
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• 1993

In an attempt to quantitate and qualitate residual antibiotics and antibacterial agents n meat simultaneously, we studied a gas chromatogrphy-mass spectrometry (GC/MS) analysis. For a simultaneous analysis of macrolide antibiotics such as erythromycin and tylosin in meat, the homogenization with MeOH, defatting with n-hexane, extraction with CHCl3, elution with CHCl3 : MeOH=2:1 from Sep-Pak silica cartridge, acid gydrolysis, back extraction with CHCl3, and quantitation by selected ion monitoring(SIM) mode after trimethylsilyl derivatization were performed. The recoveries of erythromycin and tylosin (CV,%) at 10 ppm fortification level were 90.59(4.89) and 45.91(0.20) , and the detection limits of those were 0.02 and 2.0 $\mu\textrm{g}$/g beef, respectively. From these results, the developed analytical method using GC/MS-SIM mode allows excellent detection and quantitation of residual macrolide antibiotics in meats, using complementary method with bio-assay.

• Analytical Science and Technology
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• v.13 no.3
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• pp.277-281
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• 2000

The solid phase microextrction (SPME) fiber which contains $100{\mu}m$ polydimethyl siloxane of a stationary phase was used for the analysis of volatile organic compounds contained in aqueous solution. sixteen volatile organic compounds, which were spiked in blank water and extracted by the headspace SPME techique, were analyzed by gas chromatography/mass spectrometry (GC/MS). Analytical results showed that the percent of average recoveries and relative standard deviations were 97% and 4.7%, respectively. The value of detection limit was ranged from 0.01 to $0.5{\mu}g/l$. These results are more accurate than those obtained by the other methods such as purge and trap and headspace methods.

• Analytical Science and Technology
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• v.7 no.3
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• pp.349-359
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• 1994

A gas chromatographic method for analyzing the gas odorants concentration in natural gas was studied. Eight odorants involving TBM and THT were completely separated by using OV-10 column. The optimization of several interrelated key parameters affecting the response of FPD such as hydrogen flow rate, air flow rate and detector temperature were accomplished. A permeation device was used to obtain calibration curves of TBM and THT. This analytical method has applied to measure TBM and THT used as a natural gas odorant blend in natural gas pipeline. In order to elucidate the relationship between odor level and odorant level feasibility test of fragrance meter was demonstrated.

• Environmental Analysis Health and Toxicology
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• v.18 no.1
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• pp.45-55
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• 2003

The alkylphenols, chlorophenols and bisphenol A were determined by gas chromatography/mass spectrom-etry-selected ion monitoring (GC/MS-SIM) mode followed by two work-up methods for comparison; isoBOC derivatization method and TBDMS derivatization method. Eleven phenols in paper samples were extracted with acetonitrile. Also, solid -phase extraction (SPE) with XAD -4 and subsequent conversion to isobutoxycarbonyl derivatives or tert.-butyldimethylsilyl derivatives for sensitive analysis with the selected ion-monitoring (SIM) mode. The SIM responses were linear with the correlation coefficient varying 0.9717 ∼ 0.9995 (isoBOC derivatization), and 0.9842 ∼ 0.9980 (TBDMS derivatization). The recoveries were 82.4 ∼ 108.8％) by area ratio of phenanthrene -d$\_$10/ vs bisphenol A-d$\^$l6/. (isoBOC derivatization and TBDMS derivatization) The range of concentrations was respectively, 0.95 ∼ 1.44 ng/g in 2,4-dichlorophenol, 1.01 ∼ 1.17 ng/g in t-butylphenol,2.17 ∼ 5.84 ng/g in pentachlorophenol, 12.68 ∼ 14.88 ng/g in nonylphenol and 30.84 ∼ 153.72 ng/g in bisphenol A.

• Toxicological Research
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• v.30 no.2
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• pp.109-116
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• 2014

Glucosinolates (GLSs) are abundant in cruciferous vegetables and reported to have anti thyroidal effects. Four GLSs (sinigrin, progoitrin, glucoerucin, and glucotropaeolin) were administered orally to rats, and the breakdown products of GLSs (GLS-BPs: thiocyanate ions, cyanide ions, organic isothiocyanates, organic nitriles, and organic thiocyanates) were measured in serum. Thiocyanate ions were measured by colorimetric method, and cyanide ions were measured with CI-GC-MS. Organic isothiocyanates and their metabolites were measured with the cyclocondensation assay. Organic nitriles and organic thiocyanates were measured with EI-GC-MS. In all treatment groups except for progoitrin, thiocyanate ions were the highest among the five GLS-BPs. In the progoitrin treated group, a high concentration of organic isothiocyanates (goitrin) was detected. In the glucoerucin treated group, a relatively low amount of goitrogenic substances was observed. The metabolism to thiocyanate ions happened within five hours of the administration, and the distribution of GLSs varied with the side chain. GLSs with side chains that can form stable carbocation seemed to facilitate the degradation reaction and produce a large amount of goitrogenic thiocyanate ions. Because goitrogenic metabolites can be formed without myrosinase, the inactivation of myrosinase during cooking would have no effect on the anti-nutritional effect of GLSs in cruciferous vegetables.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4275-4280
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• 2011

Present study describes the optimization of disk type sorptive extraction using monolithic material (Mono Trap) for the analysis of volatile aroma compounds from Lantana camara L. in combination with gas chromatography/mass spectrometry (GC/MS). Monolithic material sorptive extraction (MMSE) is a new sampling technique using a monolithic hybrid adsorptive disk (O.D. 10 mm, 1 mm thickness) made of high purity silica and activated carbon having a large surface area chemically bonded with octadecyl silane (ODS). The experimental parameters that may influence the MMSE efficiency have been optimized. Linearity, accuracy, precision and detection limits were evaluated to assess the performance of the proposed method. The method was validated with real plant samples of Lantana camara L. Twenty eight compounds including the main representative compounds of ${\alpha}$-curcumene and ${\beta}$-caryophyllene were found in analyzed samples. Results proved that proposed method could be used as a good alternative for the analysis for such volatile aroma compounds in plant samples.