• Analytical Science and Technology
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• v.20 no.6
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• pp.488-495
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• 2007

A wallpaper having many surfaces in indoor is composed of various raw materials. In this study, TVOC contribution from raw materials of PVC wallpaper was evaluated by using headspace-solid phase microextraction (HS-SPME)-GC/MS. Samples were diluent, resin stabilizer, plasticizer, filler, blowing agent and PVC resin. 9 mL of each sample was put into 22 mL glass vial and they were equilibrated for 1 hour at $100^{\circ}C$. Headspace in vial was absorbed to $75{\mu}m$ Carboxen-PDMS fiber and analyzed by GC/MS. Aromatic compounds like a toluene, ethylbenzene and xylene, ketones compounds like a acetone, methoxyacetone and 2-butanone and alkane compounds like a nonane decane and undecane were identified from raw materials. And alcohol compounds like a ethanol and butanol and aldehydes were detected. TVOC emission of diluent, resin stabilizer, plasticizer, PVC resin, blowing agent and filler were $54.20{\mu}g/g$, $32.88{\mu}g/g$, $0.50{\mu}g/g$, $0.88{\mu}g/g$, $0.22{\mu}g/g$ and $0.11{\mu}g/g$, respectively. Contribution of TVOC emission of diluent, resin stabilizer and PVC resin that were concerned about add ratio were 0.708, 0.129, 0.115, respectively. In conclusion, it's necessary to reduce TVOC emission through improvement of diluent, resin stabilizer and PVC resin. Also, HS-SPME-GC/MS method which was developed in this study will be used for raw materials analysis effectively.

• Carbon letters
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• v.24
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• pp.10-17
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• 2017

With continuous development in the field of sample preparation technology, solid phase micro-extraction (SPME) has been widely used in analytical chemistry for high extraction efficiency and convenient operation. Different materials lead to different extraction results. Among existing materials, carbon-based materials are still attracting attention from scientists due to their excellent physical and chemical properties as well as their modifiable surfaces, which could enhance the adsorption effects of SPME fiber. This review introduces the preparation methods and applications of different kinds of carbon-based material coatings on fibers. In addition, directions for future research on carbon material composites are discussed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.195-198
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• 2005

A solid-phase microextraction and gas chromatography-mass spectrometry for the extraction and analysis of methyl-tert-butyl ether has been described. methyl-tert-butyl ether was extracted from aqueous solution using SPME fiber coated polydimethylsiloxane and analysed by GC-MS with capillary column. Extraction parameters and chromatographic separation conditions were optimized. The applied method represented good analytical performance in terms of precision (3-8%, RSD) and accuracy(93-102%, mean recovery) with a method detection limit of 0.03 ppb.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.622-628
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• 2010

In this study, Solid-phase microextraction (SPME) with GC/FID was studied as a possible alternative to liquid-liquid extraction for the analysis of BTEX and MTBE. Experimental parameters affecting the SPME process (such as kind of fibers, adsorption time, desorption time, volume ratio of sample to headspace, salt addition, and magnetic stirring) were optimized. Experimental parameters such as CAR/PDMS, adsorption time of 20 min, desorption time of 5 min at $250^{\circ}C$, headspace volume of 50 mL, sodium chloride (NaCl) concentration of 25% combined with magnetic stirring were selected in optimal experimental conditions for analysis of BTEX and MTBE. The general affinity of analytes to CAR/PDMS fiber was high in the order p-Xylene>Toluene>Ethylbenzene>MTBE>Benzene. The linearity of $R^2$ for BTEX and MTBE was from 0.970 to 0.999 when analyte concentration ranges from $30{\mu}g/L$ to $500{\mu}g/L$, respectively. The relative standard deviation (% RSD) were from 2.5% to 3.2% for concentration of $100{\mu}g/L$ (n=5), respectively. Finally, the limited of detection (LOD) observed in our study for BTEX and MTBE were from $7.5{\mu}g/L$ to $15{\mu}g/L$, respectively.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.246-254
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• 2007

Fresh tea leaves grown in Jeju Island and Jeonnam Province of South Korea were plucked and processed. Volatile compounds (VCs) were analyzed and identified with SPME-GC/GC-MS/GC-O. The VCs of green teas were classified into two major categories based on their aroma characteristics: the Greenish (Group I), and Floral (Group II) odorants. It was found that the VCs were decreased significantly in fresh tea leaves as they were plucked at the later stages of cultivation. The ratio of VCs responsible for Group I and Group II compounds was well-balanced in tea leaves plucked in May, but the balances were changed when the fresh leaves were processed. The major VCs of fresh tea leaves in Jeju and Jeonnam were n-hexanal, E-2-hexenal, Z-3-hexenal, myrcene, benzyl alcohol, linalool, and phenyl alcohol. Also, Jeju and Jeonnam tea leaves had different aroma composition. n-Heptanol, ${\beta}-pinene$, benzaldehyde, and ethyl salicylate were found in Jeju fresh tea leaves, and Z-3-hexenol, E-2-hexenol, and methyl n-heptanoate were detected in Jeju dry tea leaves. On the other hand, Z-linalool oxide and myrcene were found in Jeonnam dry tea leaves. The SPME-GC method showed high reproducibility (RSD, 7.4%) with no-artifact formation. In this study, optimum plucking period of tea leaves could be determined for production of high quality green tea with a well-balanced aroma and characteristic VCs in green tea according to growing areas.

• Journal of Environmental Science International
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• v.23 no.10
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• pp.1693-1701
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• 2014

A rapid and simple method for the quantitative determination of volatile fatty acids (VFAs; propionic acid, n-butyric acid, i-valeric acid and n-valeric acid) and indoles (phenol, p-cresol, 4-ethyl phenol, indole and skatole) in pig slurry and dog excrement using solid-phase micro-extraction (SPME) coupled to gas chromatography was evaluated. $50/30{\mu}m$ DVB/CAR/PDMS (Divinylbenzene/Carboxen/Polydimethylsiloxane) fiber was used to extract the target compounds in aqueous media. Sample amount and adsorption time was standardized for the routine analysis. Detection limits were from 0.11 to $0.15{\mu}gL$ for VFAs and from 0.12 to $0.28{\mu}gL$ for indoles and the correlations observed ($R^2$) were 0.975~1.000. This method was applied to the pig slurry, fertilizer, compost and dog excrement. In nearly all cases, the indoles were detected in concentrations of higher than their limits of detection (DOLs). But the VFAs in swine manure were below their DOLs.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.73-86
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• 2010

The current study was designed to optimize solid phase microextraction (SPME)-GC-MS conditions for extraction and analysis of volatile components for Hanwoo beef and to establish a tentative database of flavor components. Samples were taken from Hanwoo longissimus muscle (30 mon old steer, $1^+B$ carcass grade) at 24 h postmortem. Results indicated that the optimum adsorption time for $75{\mu}m$ CAR/PDMS fiber was 60 min at $60^{\circ}C$. Thermal cleaning at $250^{\circ}C$ for 60 min was the best practice for decontamination of the fiber. A short analysis program with a sharp oven temperature ramp resulted in a better resolution and higher number of measurable volatile components. With these conditions, 96 volatile compounds were identified with little variation including 22 aldehydes, 8 ketones, 31 hydrocarbons, 12 alcohols, 8 nitrogen- and sulfurcontaining compounds, 5 pyrazines and 10 furans. A noticeable observation was the high number of hydrocarbons, aldehydes, ketones, alcohols and 2-alkylfurans which were generated from lipid decomposition especially the oxidation and degradation of unsaturated and saturate fatty acids. This implies that these compounds can be candidates for flavor specification of highly marbled beef such as Hanwoo flavor.

• Journal of Sensor Science and Technology
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• v.28 no.4
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• pp.221-224
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• 2019

Based on the results of studies on acetone excretion in diabetic patients, a one - chip sensors array was fabricated by combining acetone-selective sensor materials and volatile-organic-compound sensitive sensor materials. An electonic-nose was implemented using a sensor array and confirmed selectivity for five gases. In this system, the excretion of diabetic patients and controls was sampled with solid phase microextraction fiber and transferred to the sensor array. Although the control and diabetic patients were distinct, several samples failed. In the control group, the results of blood tests were normal, but patients were highly obese. In addition, the gas chromatography mass spectrometry results for the subjects revealed chemicals that are external factors.

• Analytical Science and Technology
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• v.24 no.2
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• pp.119-126
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• 2011

Abstract: The amount of benzene, toluene, ethylbenzene, and o-xylene (BTEX) in 30 kinds of bottled waters purchased from market and 9 kinds of tap waters from home were determined using headspace solid phase microextraction (HS-SPME). The sample was stirred at 1200 RPM G for 4 min using a magnetic bar with $100\;{\mu}m$ PDMS as adsorbent for BTEX. Then it was desorbed from the fiber for 1 min at room temperature. Quantitation was achieved using standard calibration method. The limit of detection was determined as benzene 0.39 (${\pm}0.04$) ng/mL, toluene 0.08 (${\pm}0.04$) ng/mL, ethylbenzene 0.04 (${\pm}0.01$) ng/mL, and o-xylene 0.05 (${\pm}0.02$) ng/mL. Benzene and o-xylene were not detected in any samples, but toluene was detected in 11 samples, and ethylbenzene was detected just in 3 samples among 30 investigated bottled waters. The concentration range of investigated materials for toluene and o-xylene were $0.24({\pm}0.09)\sim2.95\;({\pm}0.08)\;ng/mL$, $0.08({\pm}0.06)\sim0.93({\pm}0.10)\;ng/mL$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.201-208
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• 2007

Functional oils (FOs) were produced from commercial diacylglycerol oil and red yeast rice extracts from 80% ethanol for 1 hr in a shaking water bath at $35^{\circ}C$ and 175 rpm. FOs contained (A) 600, (B) 1200, (C) 1800, and (D) 2280 ppm of red yeast-rice extracts, respectively. The Hunter a value and b value were risen whereas L value was reduced along with the increase of extract concentration. Content of monacolin K and total phenolic compounds in FOs significantly increased according to the increase of extract concentration. The oxidation stability of FOs was observed by Rancimat at $98^{\circ}C$. Induction time decreased according to the increase of extract concentration. The major volatile compounds of FOs were compared using the electronic nose (EN) system and solid phase microextraction (SPME) method combined with gas chromatograph/mass spectrometry (GC/MS). EN was composed of 12 different metal oxide sensors. Sensitivities (Rgas/Rair) of sensors from EN were analyzed by principal component analysis (PCA), whose proportion was 99.66%. For qualitative or quantitative analysis of volatile compounds by SPME-GC/MS, the divinylbenzene/carboxene/polydimethyl-siloxane fiber and sampling temperature of $50^{\circ}C$ were applied.