• Mass Spectrometry Letters
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• 제4권1호
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• pp.18-20
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• 2013

Headspace solid phase micro-extraction gas chromatography/flame ionization detection (HS-SPME-GC/FID) method was compared with headspace gas chromatography/mass selective detection (HS-GC/MS). Organic solvent-spiked urine as well as urine samples from workspace was analyzed under optimal condition of each method. Detection limit of each compound by HS-SPME-GC/FID was $3.4-9.5{\mu}g/L$, which enabled trace analysis of organic solvents in urine. Linear range of each organic solvent was $10-400{\mu}g/L$, with fair correlation coefficient between 0.992 and 0.999. The detection sensitivity was 4 times better than HS-GC/MS in selected ion monitoring (SIM) mode. Accuracy and precision was confirmed using commercial reference material, with accuracy around 90% and precision less than 4.6% of coefficient of variance. Among 48 urine samples from workplace, toluene was detected from 45 samples in the range of $20-324{\mu}g/L$, but no other solvents were found. As a method for trace analysis, SPME HS GC/FID showed high sensitivity for biological monitoring of organic solvent in urine.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2691-2696
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• 2013

The electronic cigarette (E-cigarette) is a battery-powered device that aerosolizes nicotine so that it is readily delivered into the respiratory tract. The analytical data regarding the substances present in E-cigarettes are very limited. The aim of this study was to measure the concentration of aldehydes-formaldehyde (FA), acetaldehyde (AA) and, acrolein (AL)-in 225 replacement liquid brands from 17 E-cigarette shops sold in the Republic of Korea by headspace solid-phase micro extraction and gas chromatography-mass spectrometry (HS-SPME GC-MS). The concentration range of FA and AA was 0.02-10.09 mg/L (mean = 2.16 mg/L, detected in 207 of 225 samples) and 0.10-15.63 mg/L (mean = 4.98 mg/L, detected in all samples), respectively. AL was not detected in any of 225 replacement liquids. FA and AA were originally present in almost all replacement liquids of electronic cigarettes.

• Mass Spectrometry Letters
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• 제8권1호
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• pp.18-22
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• 2017

Products containing any one or more of 26 fragrance allergens likely to cause contact allergies, are required under the 2008 domestic cosmetic law to be labeled when their concentrations exceed a certain range. This study focuses on the comparison and development of analytical methods based on headspace-solid phase micro extraction (HS-SPME) and liquid-liquid extraction (LLE) methods followed by GC-MS/MS for 24 of the fragrance allergens excepting for two natural materials in water samples. Using the developed HS-SPME method, 15 of the 24 fragrance allergens were analyzed and 9 compounds which have relatively low $logK_{OW}$ values (below about 2.5) were not extracted, and the correlation coefficient ($r^2$) of the calibration curve for quantification showed linearity of 0.9969 or more, and the method detection limits (MDL) and the limits of quantification (LOQ) were $0.078{\sim}0.582{\mu}g/L$ and $0.261{\sim}1.940{\mu}g/L$, respectively. In the case of using the optimized LLE method, all 24 fragrance allergens were analyzed, and the correlation coefficient ($r^2$) of the calibration curve for quantification showed linearity of 0.9957 or more, MDL and LOQ were $0.020{\sim}0.138{\mu}g/L$ and $0.065{\sim}0.440{\mu}g/L$, respectively.

• 분석과학
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• 제25권1호
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• pp.39-49
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• 2012

HS-SPME GC-MS에 의한 지표수 중에 37개 휘발성유기물질을 동시에 분석하는 방법을 개발하였다. 이 방법은 물 중 휘발성유기물질을 헤드스페이스 vial에서 $40 ^{\circ}C$에서 30분간 가열 85 ${\mu}m$ carboxen-polydimethylsiloxane에 흡착시키는 방법이다. 4.0 mL의 물 시료를 사용하여 확립한 조건하에서 정량한계는 4.1-96 ng/L의 범위를 나타냈고 이러한 검출한계는 US EPA 또는 독일에서 확립한 준거치의 1/10 이하 값을 만족시켰으며 0.05 ${\mu}g/L$와 0.50 ${\mu}g/L$의 농도에서 정밀도는 15% 이내를 보였다. 이 정량한계는 준거치를 결정하기 위한 조사연구에서 요구하는 최소 감도이다. 확립한 방법을 사용하여 금강물 16개 시료를 분석한 결과 16개 휘발성유기화합물이 검출되었으며 측정값은 US EPA 또는 독일에서 확립한 준거치 이하의 값을 보였다.

• Journal of Microbiology and Biotechnology
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• 제32권3호
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• pp.307-316
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• 2022

Yeasts play an important role in spontaneous fermentation of traditional alcoholic beverages. Our previous study revealed that a mixed-consortia of both Saccharomyces and non-Saccharomyces yeasts were responsible for fermentation of khadi, a popular, non-standardized traditional beverage with an immense potential for commercialization in Botswana. Functional characterization of isolated fermenting yeasts from mixed consortia is an indispensable step towards the selection of potential starter cultures for commercialization of khadi. In this study, we report the characterization of 13 khadi isolates for the presence of brewing-relevant phenotypes such as their fermentative capacity, ability to utilize a range of carbon sources and their ability to withstand brewing-associated stresses, as a principal step towards selection of starter cultures. Khadi isolates such as Saccharomyces cerevisiae, Saccharomycodes ludwigii and Candida ethanolica showed good brewing credentials but Lachancea fermentati emerged as the isolate with the best brewing attributes with a potential as a starter culture. However, we were then prompted to investigate the potential of L. fermentati to influence the fruity aromatic flavor, characteristic of khadi. The aroma components of 18 khadi samples were extracted using headspace solid phase micro-extraction (HS-SPME) and identified using a GC-MS. We detected esters as the majority of volatile compounds in khadi, typical of the aromatic signature of both khadi and L. fermentati associated fermentations. This work shows that L. fermentati has potential for commercial production of khadi.