• Environmental Analysis Health and Toxicology
• /
• v.16 no.3
• /
• pp.121-126
• /
• 2001

Analytical method of benzophenone (BP) in sediment and soil was developed by gas chromatography/mass selective detector/selected ion monitoring (GC/MSD/SIM). The ultrasonic extraction of US EPA (method 3550B) method and liquid-liquid extraction for sediment and soil samples were used for the analysis of BP from sediment and soil. BP was extracted with n-hexane. Organic layer was washed with 5% sodium chloride solution. 1∼2 l of the concentrated solution of organic layer was applied to GC/MSD. The retention time of BP peak was 11.10 min. Recovery (％) of BP by ultrasonication from sediment and soil samples was 96.0∼100.6％ and 40.0∼83.0％, respectively. Recovery of BP by liquid-liquid extraction was 51∼59％ in soil samples. The detection limit of BP in sediment and soil samples were determined to 0.1 ng/g.

• Environmental Analysis Health and Toxicology
• /
• v.15 no.1_2
• /
• pp.45-51
• /
• 2000

Analytical method of 4-nitrotoluene (4-NT) in water was developed by 9as chromatography/mass selective detector/selected ion monitoring (GC/MSD/SIM). 4-NT was extracted with diethyl ether. Organic layer was washed with 5 % sodium chloride solution. The influence of solvent and evaporation condition on extraction of 4-NT were examined. The retention time of 4-NT peak was 7.72 min. Coefficient of variation (CV) of 4-NT (ng) within day and day-to-day was ranged from 7.0 to 14.6% and from 7.7 to 20.8%, respectively. Recovery of 4-NT was ranged from 84 to 109%, and detection limit of 4-H was lese than 1 ng/㎖.

• Analytical Science and Technology
• /
• v.12 no.5
• /
• pp.408-414
• /
• 1999

A selective and sensitive method for the derivatization of total homocysteine (Hcy) and the related compounds in plasma by gas chromatograph (GC)-electron capture detector (ECD) has been developed. To determine total homocysteine, cysteine (Cys), and methionine (Met) in human plasma using GC-ECD, analytes were reduced and converted into their N(O,S)-ethylearbonyl pentafluoropropyl (PFP) ester by derivatization with ethyl chloroformate and pentafluoropropyl alcohol (PFP-OH) in plasma. The best derivatizing agent N(O,S)-ethyl carbonyl PFP ester, was chosen by comparing the sensitivity of derivatized analysis in GC-ECD. The derivatized analytes in plasma were extracted by chloroform, and subsequently back-extracted with hexane and analyzed by GC-ECD. The calibration carves ($R^2$ > 0.990) were linear over the range $5-50{\mu}mol/L$ of Hcy and Met, $40-400{\mu}mol/L$ of Cys spiked in plasma. The detection limit observed by the established method was below $0.5{\mu}mol/L$. This method is highly sensitive and specific in the analysis of Hcy, Cys, and Met. Therefore, we suggest that this method is appropriate in the analysis of trace concentration of Hcy, Cys, and Met in biological fluids.

• Analytical Science and Technology
• /
• v.17 no.4
• /
• pp.322-336
• /
• 2004

The improved derivatization technique of tamoxifen metabolite in human urine is described for the acylation method that they are substituted by derivatization reagent like acyl anhydride for use of gas chromatography/mass spectrometry. The hydroxyl group of tamoxifen metabolite was derivatized by trifluoroacetic anhydride (TFAA), pentafluoroacetic anhydride (PFPA) and heptaflorobutylic anhydride (HFBA). It was investigated to the gas chromatography/mass spectrometry (GC/MS) technique use negative ion chemical ionization (NCI), positive ion chemical ionization (PCI) and electron impact (EI). In acylation of the metabolites of tamoxifen, the effective reaction temperature and time were shown to be at $50^{\circ}C$ for 30 min. The 4-hydroxytamoxifen, which is known to major metabolite of tamoxifen, was not detected in human urine, whileas the hydroxymethoxytamoxifen was detected. We thought that this result was from the single dose of tamoxifen.

• Applied Chemistry for Engineering
• /
• v.26 no.3
• /
• pp.311-318
• /
• 2015

This work investigated the plasma treatment of aqueous bisphenol A (BPA) solution and mineralization pathways. For the effective contact between plasmatic gas and aqueous BPA solution, the plasma was created inside a porous ceramic tube, which was uniformly dispersed into the aqueous solution through micro-pores of the ceramic tube. Effects of the gas flow rate, applied voltage and treatment time on the decomposition of BPA were examined, and analyses using ultraviolet (UV) spectroscopy, ion chromatography and gas chromatography-mass spectrometry were also performed to elucidate mineralization mechanisms. The appropriate gas flow rate was around $1.0L\;min^{-1}$; when the gas flow rate was too high or too low, the BPA decomposition performance at a given electric power decreased. The increase in the voltage improves the BPA decomposition due to the increased electric power, but the energy required to remove BPA was similar, regardless of the voltage. Under the condition of $1.0L\;min^{-1}$ and 20.8 kV, BPA at an initial concentration of $10L\;min^{-1}$ (volume : 1 L) was successfully treated within 30 min. The intermediates produced by the attack of ozone and hydroxyl radicals on BPA were further oxidized to stable compounds such as acetate, formate and oxalate.

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

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

• Journal of Applied Biological Chemistry
• /
• v.58 no.2
• /
• pp.175-181
• /
• 2015

Compositions of essential oils extracted from mint herb such as Mentha piperita, Mentha spicata, and Mentha ${\times}$ piperita var. citrate produced in Jeju were analyzed using gas chromatography-mass spectrometry (GC-MS) and headspace-GC-MS (HS-GC-MS). By the GC-MS analysis, 13 compounds were tentatively identified in Mentha piperita, Mentha spicata, and Mentha ${\times}$ piperita var. citrate, respectively. Peperitenone oxide, carvone, and linalool were detected as major compounds in Mentha piperita, in Mentha spicata, in Mentha ${\times}$ piperita var. citrate, respectively, based on the ratio of peak intensity in the total ion chromatogram. The greater number of compounds, including volatile alcohols and acetates were identified by HS-GC-MsS than by GC-MS in these all three essential oils. Similar patterns of composition were detected in both Mentha spicata and Mentha ${\times}$ piperita var. citrate by either one of GC-MS methods. However, in case of Mentha piperita, $\small{L}$-(-)-menthol, which was identified as the major compound by HS-GC-MS was detected in dramatically reduced quantity by GC-MS. Interestingly, we found that both linalyl acetate and linalool were identified as the dominant compounds in the essential oil of Mentha ${\times}$ piperita var. citrate.

• Analytical Science and Technology
• /
• v.16 no.6
• /
• pp.458-465
• /
• 2003

The HS (headspace)-SPME (Solid phase microextraction) as rapid and simple method was performed for the determination of volatile fatty acids (VFAs) from the aqueous samples. In-fiber derivatization of VFAs with 1-Pyrenyldiazomethane (PDAM) was applied to improve their sensitivity of detection. In SPME procedure, typical parameters such as effects of solution pH, and salting out reagent and ultrasonication were investigated to improve the extraction efficiency. Based on the developed method, VFAs in wastewater samples were determined by gas chromatography / mass spectrometry-selected ion monitoring (GC/MS-SIM) mode.

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