• Journal of Environmental Science International
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• v.22 no.12
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• pp.1539-1549
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• 2013

The purpose of this study is to compare the sampling methods for monitoring indoles (phenol, p-cresol, indole and skatole) in airs of swine facility. As the collecting methods of indoles in air, Tenax-TA adsorption tube and solid phase microextraction (SPME) were examined. For the preparation of calibration curves of indoles concentrated in Tenax-TA, the standard indoles solutions were spiked in each of Tenax-TA tubes and thermally desorbed (ATD) into a gas chromatograph combined with mass detector (GC/MS). And for the preparation of calibration curves by SPME, indoles in the standard gaseous solution prepared by evaporating the aqueous solution that contained indoles into a polyester sampling bag were extracted with SPME fiber and subsequently analyzed by the GC/MS. Two sampling methods were evaluated for extracting indoles present in swine building environments. Results indicated that the SPME method using Polydimethylsiloxane/ Divinylbenzene (PDMS/DVB) fiber was more effective than Tenax-TA method in extracting indoles. The gas chromatographic analysis showed that the linearities of calibration curves and detection limits were useful for detection of indoles in swine airs. The field tests also showed that considerably different levels of indoles were present in various parts of the swine building.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.6
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• pp.523-538
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• 2009

Recently, there has been a keen demand for real-time automatic monitoring of VOCs not only in Korea but other developed countries. We carried out this study to evaluate and to optimize the performance of a continuous automatic monitoring system for hazardous VOCs (HVOCs) in the ambient atmosphere, using an on-line GC system. The online system normally consisted of a Nafion dryer prior to a cold trap of an automatic thermal desorption apparatus and a GC system equipped with two detectors, i.e. PID and ECD. Preliminary tests conducted to check out any contamination of the system revealed an evidence of significant artifact formation of benzene, and it was found that the Nafion dryer (even brand new one) is the source of the benzene artifact. Thus, all the subsequent experiments in this study was carried out inevitably by removing the Nafion dryer. The on-line GC method was investigated with a variety of QC/QA performance criteria such as repeatability, linearity, lower detection limits, and accuracy. In order to find out the best operating condition for the on-line GC system, three different types (in terms of adsorption strength) of cold trap combinations were tested, i.e. (i) Tenax-TA and Carbopack-B combination (weak and hydrophobic); (ii) Tenax-TA, Carbopack-X and Carboxen-1000 combination (strong and hydrophilic); and (iii) Tenax-TA and Carbopack-X combination (medium and hydrophobic/hydrophilic). The USEPA TO-17 manual method was selected as a reference method to evaluate the performance of the on-line method. A series of experiments revealed that the system performance was superior to others when a cold trap packed with hydrophilic adsorbents (Tenax-TA/Carbopack-X/Carboxen-1000 combination) was used and operated at $25^{\circ}C$. However, the system with a cold trap packed with a combination of Tenax-TA and Carbopack-X is more recommended for field applications since the carboxen-1000 adsorbent is too sensitive to water vapor, and hence the performance of the system might be very unstable to humid samples or during rainy days. Furthermore, the precision and accuracy criteria of the Tenax-TA/ Carbopack-X combination were generally compatible with the triple adsorbents cold trap. The continuous automatic monitoring method is, thus, considered very useful to real-time monitoring to understand the variations of VOCs concentrations in ambient air, as it adopts much simpler procedures in sampling, analysis, and data integration steps than manual monitoring methods. However, it should be noted that there is a high possibility of benzene artifacts formation through the Nafion dryer, which is often installed to remove water vapor in air samples before being adsorbed onto the cold trap. Therefore, if a Nafion dryer is used in any studies of monitoring VOCs, the benzene contamination should be carefully examined before carrying out obtaining the data.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.2
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• pp.127-137
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• 2002

Phenolic compounds in air are toxic even at their low concentrations. We had evaluated a total of five phenolic compounds (Phenol, o-Cresol, m-Cresol, 2-Nitrophenol and 4-Chloro-3-methylphenol) in artificial air using a combination of ATD/GC/MS. To compare the adsorption efficiency of these phenolic compounds, three adsorbents (Tenax TA, Carbotrap and Carbopack B) were tested. Tenax TA adsorbent was most effective of all the adsorbents used for the efficiency test. Five phenolic compounds were found to be very stable on adsorbent tubes for 4 days at room temperature. Detection limit of five phenolic compounds ranged from 0.05 to 0.08 ppb (when assumed to collect 10 L air). The calibration curve was linear over the range of 22∼ 164 ng. The reproducibility was less than 4%. Sampling of duplicate pairs (DPs) was made to demonstrate duplicate precision and sampling efficiency.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.17 no.1
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• pp.29-38
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• 1991

As the suitable place of the forest bathing, Two places of the needle-leaf trees, which are located in the Oh-Saek mineral spring near place from the Sorak mountain, were selected. And then, Headspace gas trapping apparatus were setted in that two places and the aromatic components of the forest were adsorbed by Tenax-TA column for 24 hours. And Tenax-TA column were analyzed by the GC SE GC-MS. The analyzed components were found to contain up to between 70-80% of pollutants, which are Toluene, Methyl Chloride, Hexane, p-Xylene, Benzene, ... etc. On the other hand, the aromatic components of the forest, which give aromatheraphitical effectness, are as follow: alpha-Pinene, Limonene, 1, 8-Cin-eol, Benzaldehyde, . . . etc.

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.220-228
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• 2004

Dynamic headspace purge conditions were investigated to obtain minimum loss of high volatile compounds by breakthrough and maximum recovery of low volatile components of roasted perilla seed oil (RPSO). A response surface methodology was applied to evaluate the effect of purge temperature, purge time, and sample weight on $\ell$ n (total peak area), breakthrough ratio, and peak area of perilla ketone the least volatile component of RPSO. Sample weight was the most important factor on the $\ell$ n (total peak area) but it did not affect peak area of perilla ketone. All process variables significantly influenced breakthrough ratio. The optimum condition was determined by superimposing contour plots at purge temperature of 48$^{\circ}C$ for 12 min purge time at sample weight of 0.60 g. 2-Propanone, 2-butanone, acetic acid, 2-methyl propanal were main breakthrough compounds in RPSO flavor.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.10a
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• pp.148-151
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• 2010

화재증거물 속의 인화성물질을 분석하는 기술은 현재 다양한 추출 및 농축법을 활용한다. 본 연구에서는 Tenax TA를 이용하여 화재증거물 속의 인화성물질을 농축한 후 자동열탈착 장비를 사용하여 Tenax TA관 속에 농축되어 있는 인화성물질을 자동열탈착시켜 GC로 보낸 후 MS 분석하는 기술을 소개한다. 이러한 전처리과정을 사용하여, 화재증거물속의 인화성물질(경유, 등유 등)을 분석하였는데, 물로 화재증거물을 물을 이용하여 소화하여도, 시간이 오래지난 화재증거물이라도 열탈착 장비를 이용한 분석은 경유, 등유등을 확인하는데 유용하였다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.11a
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• pp.500-502
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• 2006

본 연구에서는 김해시 동지역을 중심으로 생활형태별로 상업지역, 주거지역, 도로지역, 공단지역으로 구분하여 Tenax TA로 3시간 간격으로 포집하여 일간 변화를 측정하였다. 이를 GC/MS를 이용하여 정량분석하여 생활형태별 일간 농도변화를 관측하였다. 생활형태별로 휘발성유기화합물의 농도는 도로지역, 공단지역, 상업지역, 주거지역 순으로 나타났으며, 시간에 따른 농도 변화는 오존전구 물질인 휘발성유기화합물의 반응이 빠른 낮시간보다 밤시간에 상대적으로 높게 검출되었다.

• Analytical Science and Technology
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• v.24 no.4
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• pp.290-297
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• 2011

In present, evaluation method for car cabin air quality has been developed in ISO, China, Japan. Also The management standard for new produced car has been applied since 1, July, 2010. To manage car cabin air quality, It is important to evaluate VOC emitted from interior material. In this study, complete component of door trim armrest was evaluated in accordance with ISO 12219-5, cut component was evaluated in accordance with ISO 12219-3. The vapour gas was collected with stainless tube packed with Tenax TA and analyzed with TD-GC/MS. It was confirmed that emission rate of each compounds was difficult in each evaluation method. As a result, to evaluating each components composing door trim armrest, main sources of emitting VOCs in door trim armrest were PP substrate and adhesive.

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.35-42
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• 2009

Headspace micro solid phase extraction using mulberry paper bag (HS-MPB-$\mu$-SPE) has been developed and validated for the analysis of volatile flavor compounds from five spice by gas chromatography-mass spectrometry (GC/MS). HS-MPB-$\mu$-SPE was performed with adsorbent particles enclosed inside a mulberry paper bag. Four different kinds of adsorbents such as Tenax TA, Porapack Q, dimethylpolysiloxane and polyethylene glycol were tested. The extraction solvents compared were petroleum ether, methylene chloride, and chloroform. Better results were obtained when Tenax TA and petroleum ether were used. The limit of detection (LOD) and the limit of quantitation (LOQ) were in the range of 1.3 ng/mL and 4.3 ng/mL, respectively, for o-cymene as a model compound of monoterpene. Proposed method showed good reproducibility (3.3%, RSD) and good recoveries (94.0%). The HS-MPB- μ-SPE is very simple to use, inexpensive, rapid, requires small sample amounts and solvent consumption. Because the solvent for extraction is reduced to only a very small volume (0.6 mL), there is minimal waste or exposure to toxic organic solvent and no further concentration step. This method allows successful characterization of the headspace in contact with the five spice sample. Strong trans-anethole from star anise or fennel is a characteristic flavor of five spice powders. HS-MPB-$\mu$-SPE combined with GC/MS can be a promising technique for the broad spectrum measurement of volatile aroma compounds from solid spices.

• Asian Journal of Atmospheric Environment
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• v.8 no.4
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• pp.192-201
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• 2014

A comprehensive profile of volatile organic compounds (VOCs) in public spaces is needed for interpreting indoor air measurements. Seasonal differences in profiles are critical for epidemiological study and risk assessment. The purposes of this study were to establish profiles for individual VOCs in 50 indoor public places in Korea and to determine seasonal variations in their concentrations. Air samples were taken during working hours. Seventy-two of the 91 targeted VOCs were identified using multiple standards. Six VOCs detected in all summer and winter samples were toluene, acetone, m,p-xylenes, ethylbenzene, benzene, and styrene. In summer, methyl ethyl ketone and 1-butanol were also found in all samples. In both seasons, the dominant indoor VOCs were toluene, m,p-xylenes, ethylbenzene, acetone, and isopropyl alcohol. Other chemicals associated with gasoline emissions were dominant in summer. Limonene was dominant only in winter due to the consumption of tangerines. The nine VOCs with the highest concentrations comprised 64.8% and 49.6% of the TVOC in summer and winter, respectively. Comparing two types of adsorbent tube, a single adsorbent tube with Tenax-TA had similar detection performance as a double adsorbent tube with Tenax and Carbotrap.