• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.906-917
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• 2013

The purpose of this study is to quantify volatile organic compounds (VOCs) in gas sample using headspace solid-phase microextraction (HS-SPME) coupled to GC analysis. The optimal HS-SPME conditions was CAR/PDMS fiber and 30 min absorprion time for the analysis of various VOCs. In optimal conditions, 80 VOCs could be detected within 1 ppbv and even less than 0.0005 ppbv especially in the case of BTEX. However, fiber reproducibility on adsorption efficiency was 1~9.2% (between the same fiber) and 5.9~13.5% (between the other fiber). We successfully determined 35 VOCs in landfill gas with this method and found that VOCs of high concentration are emitting from vent pipe of closed/open landfill site under the HS-SPME conditions. This method may apply to VOCs/odor determination from various atmospheric environmental samples as well as landfills.

• Journal of the Korean GEO-environmental Society
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• v.11 no.5
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• pp.61-67
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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 chlorinated solvents (PCE and TCE) and these by-products (cis-DCE, VC, and Ethylene). 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 50mL, sodium chloride (NaCl) concentration of 25% combined with magnetic stirring were selected in optimal experimental conditions for analysis of chlorinated solvents and these by-products. The general affinity of analytes to CAR/PDMS fiber was high in the order PCE>TCE>cis-DCE>VC>Ethylene. The linearity of $R^2$ for chlorinated solvents and these by-products was from 0.912 to 0.999 when analyte concentrations range from $10{\mu}g/L$ to $500{\mu}g/L$, respectively. The relative standard deviation (% RSD) were from 2.1% to 3.6% for concentration of $500{\mu}g/L$ (n=5), respectively. Finally, the limited of detection (LOD) observed in our study for chlorinated solvents and these by-products were from $0.5{\mu}g/L$ to $10{\mu}g/L$, respectively.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.1
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• pp.27-35
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• 2014

The headspace solid-phase microextraction (HS-SPME) followed by gas chromatography/mass spectrometry procedure has been developed for the simultaneous determination of petroleum aromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene isomers (BTEX) and polycyclic aromatic hydrocarbons (PAHs) in seawater. The advantages of SPME compared to traditional methods of sample preparation are ease of operation, reuse of fiber, portable system, minimal contamination and loss of the sample during transport and storage. SPME fiber, extraction time, temperature, stirring speed, and GC desorption time were key extraction parameters considered in this study. Among three kinds of SPME fibers, i.e., PDMS ($100{\mu}m$), CAR/PDMS ($75{\mu}m$), and PDMS/DVB ($65{\mu}m$), a $65{\mu}m$ PDMS/DVB fiber showed the most optimal extraction efficiencies covering molecular weight ranging from 78 to 202. Other extraction parameters were set up using $65{\mu}m$ PDMS/DVB. The final optimized extraction conditions were extraction time (60 min), extraction temperature (50), stirring speed (750 rpm) and GC desorption time (3 min). When applied to artificially contaminated seawater like water accommodated fraction, our optimized HS-SPME-GC/MS showed comparable performances with other conventional method. The proposed protocol can be an attractive alternative to analysis of BTEX and PAHs in seawater.

• 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.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.6
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• pp.713-719
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• 2005

SPME (Soild phase microextraction) has been used in the analysis of many volatile organic compounds, such as geosmin and 2-methylisoborneol (2-MIB), trihalomethanes (THMs) in drinking water. SPME fiber is characterized by high adsorption capacity (DVB/CAR/PDMS, DVB/PDMS etc.). Although the highly active adsorption capacities of the SPME fiber are often to the chemical functional group, surface properties play a significant role in determining the surface adsorption capacities. The objectives of this study were to evaluate effect of residual chlorine on analysis of geosmin and 2-MIB. Image taken by SEM before preloaded with chlorine, the surface and porous media was almost perfect spherical shape and no clogging of pores. However, after preloaded with chlorine the surface was aggregated and pore was blocked. The recovery rate of geosmin and 2-MIB coexisting with chlorine was reduced by 35 to 62%. The recovery rate with preloaded with chlorine was reduced by 25 to 43%. The lower concentration of geosmin and 2-MIB and the higher concentration of chlorine existed in water, the lower the recovery rate was.

• Analytical Science and Technology
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• v.21 no.2
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• pp.93-101
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• 2008

The application of solid phase microextraction (SPME) is generally conducted by directly immersing the fiber into the liquid sample or by exposing the fiber in the head space (HS). The extraction temperature, the time of incubation, and application of stirring are often designated to be the most important parameters for achieving the best extraction efficiencies of HS-SPME analysis. In this study, relative importance of these three analytical parameters involved in the HS-SPME method is evaluated using a polydimethylsiloxane/carboxen (PDMS/CAR) fiber. To optimize its operation conditions the competing relationships between different parameters were investigated by comparing the extraction efficiency based on the combination of three parameters and two contracting conditions: (1) heating the sample at 30 vs. 50 C, (2) exposing samples at two durations of 10 vs. 30 min, and (3) application of stirring vs. no stirring. According to our analysis among 8 combination types of HS-SPME method, an extraction condition termed as S50-30 condition ((1) 1200 rpm stirring, (2) $50^{\circ}C$ exposure temp, and (3) 30 min exposure duration) showed maximum recovery rate of 45.5~68.5% relative to an arbitrary reference of direct GC injection. According to this study, the employment of stirring is the most crucial factor to improve extraction efficiency in the application of HS-SPME.

• Bulletin of the Korean Chemical Society
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• v.25 no.2
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• pp.271-279
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• 2004

The aroma component of Hallabong peel has been characterized by GC-MS with two different extraction techniques: solid-phase trapping solvent extraction (SPTE) and headspace solid-phase microextraction (HSSPME). Aroma components emitted from Hallabong peel were compared with those of other citrus varieties: lemon, orange and grapefruit by SPTE and GC-MS. d-Limonene (96.98%) in Hallabong was the main component, and relatively higher peaks of cis- ${\beta}$-ocimene, valencene and -farnesene were observed. Other volatile aromas, such as sabinene, isothujol and ${\delta}$-elemene were observed as small peaks. Also, principal components analysis was employed to distinguish citrus aromas based on their chromatographic data. For HSSPME, the fiber efficiency was evaluated by comparing the partition coefficient ($K_{gs}$Kgs) between the HS gaseous phase and HS-SPME fiber coating, and the relative concentration factors (CF) of the five characteristic compounds of the four citrus varieties. 50/30 ${\mu}$m DVB/CAR/PDMS fiber was verified as the best choice among the four fibers evaluated for all the samples.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.895-899
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• 2009

A new approach for the determination of acrylamide (AM) in foods by solid phase microextraction-gas chromatography (SPME-GC) was established. AM was bromized and transformed to 2-bromoacrylamide (2-BAM). 2-BAM was then extracted by a commercial SPME fiber, $75-{\mu}m$ Car/PDMS fiber, for GC detection. The influence of extraction and desorption parameters such as extraction temperature and time, stirring rate, desorption temperature, and time were studied and optimized. The mass concentration was proportional to the peak area of 2-BPA from 1.0 to 8,000 ${\mu}g/L$. The detection limit of the SPME-GC for 2-BAM was found to be 0.1 ${\mu}g/L$, and the recoveries and relative standard deviations for different food samples were 74.5 to 102.0%, and 4.2 to 9.1%, respectively. The presented method was applied to the determination of AM in fried foods.

• 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.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.695-701
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• 2005

Efficient method was established for analysis of sulfur-containing compounds, including dimethyl disulfide, dimethyl trisulfide, 3-methyl thiophene, allyl mercaptan, 2-methyl-3-furanthiol, and methional. Sulfur-containing compounds were extracted through solid phase microextraction (SPME) or static headspace extraction (SH), and quantified using gas chromatograph equipped with pulsed flame photometric detector. All sulfur compounds, except ally mercaptan, showed higher detection response when dissolved in hexane than in dichloromethane. Linear range was $10^2-10^4$. Dimethyl trisulfide showed lowest limit of detection (LOD) value of 15.2 ppt, and methional highest of 70.5 ppb. Highest extraction efficiency for sulfur-containing compounds, particularly polar and small molecular weight compounds, was observed in 75mm carboxen/polydimethylsiloxane fiber, followed by 65mm polydimethylsiloxane/divinylbenzene and 100mm polydimethylsiloxane. Compared to SPME, less sulfur-containing compounds could be analyzed by SH, mainly due to its low extraction efficiency, although lower amount of artifacts were formed during sample preparation.