• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.140-140
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• 2001

A sensitive analytical method based on gas chromatograpy-mass spectrometry with a selected ion monitoring (GC/MS-SIM) with the purge-and-trap concentration and with headspace method (in limited applications) was developed for determining of epichlorohydrin in canned beverages coated with epoxy resin. The calibration curve in the range of $0.5\sim50ng$ had correlation coefficient greater than 0.998 and a detection limit of $0.l\mug/L$ was obtained using a sample volume of 20ml. The predominant ions of epichlorohydrin produced in MSD using electron ionization(EI) were m/z 57 ([M-CI]+) and 62/64 $([M-CH_2O]+)$. In survey of epichlorohydrin in thirty commercial canned beverage samples, none of them was detected.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.164.2-165
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• 2003

Structured lipids (SLs) are defined as triacylglycerols to change the fatty acid composition in the glycerol backbone and lipases are known as a powerful tool for the syntheses of SLs. Structured lipid from corn oil, capric acid, and conjugated linoleic acid (CLA) by transesterification reaction and using several amounts of immobilized lipase RM IM (from Rhizomucor miehei) was studied, and 4% of lipase amount was selected for further study as the optimal amount. Comparison the chemical properties (free fatty acid value, iodine value, saponification value, tocopherols, and color analysis), solidification behavior, and volatile fractions (from headspace SPME GC-MS) between com oil and SL com oil was obtained.

• Korean Journal of Medicinal Crop Science
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• v.8 no.1
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• pp.49-57
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• 2000

To understand the effects of drying conditions on changes of volatile compounds in fruits of Schizandra chinensis, we analyzed SDE (steam distillation and extraction) extract and Headspace vapor of fresh and dried samples using GC/MS (Gas chromatograph/Mass spectrometer). Contents of essential oils from samples with different drying conditions were 0.58% in fresh ones, 0.60% in freeze dried ones, and 0.30% in hot-air dried ones. In SDE extract, major volatile compounds in fresh samples were terpinen-4-ol(9.01%), ${\gamma}-terpinene(7.02%),\;{\beta}-myrcene(7.55%)$, unidentified sesquiterpenes(28.48%), showing almost the same composition as that in freeze-dried ones, but those in hot-air dried samples at $60^{\circ}C$ were ${\gamma}-terpinene(5.40%),\;{\alpha}-elemene(8.28%)$, unidentified sesquiterpenes(50.38%), indicating the chemical changes during drying procedure. In Headspace vapor, major compounds in fresh samples were ${\beta}-myrcene(22.05%),\;{\gamma}-terpinene(9.47%),\;{\alpha}-pinene(8.91%)$, sabinene(8.48%), which were different from those in SDE extract. In chemical compositions of volatile compounds in dried samples, ${\beta}-myrcene,\;{\alpha}-terpinene$ decreased in the order of freeze-drying > hot-air drying at $60^{\circ}C$ > hot-air drying at $60^{\circ}C$, and ${\alpha}-ylangene,\;{\alpha}-pinene$, camphene increased in the reverse order of the former. We observed the changes of the contents and compositions of essential oils compounds during drying procedure, especially a decrease in monoterpenes and alcohols and an increase in sesquiterpenes with relatively weak volatility.

• Analytical Science and Technology
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• v.25 no.6
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• pp.395-401
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• 2012

This study presents a method for the quantitative analysis of residual vinyl chloride monomer (VCM) in PVC products. In elution solvent, the extraction efficiency was similar by ethanol, THF, and acetone, but using n-hexane, it indicated relatively low extraction efficiency. Measuring VCM in the pulverized PVC samples, it showed reasonable results in both the direct injection method and headspace method with GC/MS. Regarding analysis of VCM in the intermediate sponge samples, five laboratories showed good results, and from the results, it was considered that VCM quantitative method in this study was reliable.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2001.12a
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• pp.123-123
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• 2001

주류는 미생물에 의한 효소작용으로 원료 성분이 분해됨으로서 생성되는 당분, 아미노산, 유기산등의 맛 성분과 발효과정 동안 생성되는 휘발성 성분들이 조화되어 상당히 다양한 성분들이 향미에 관여하므로 향기의 주성분 규명이나 향기성분을 이용한 품질의 규격화가 매우 어려운 문제로 보여진다. 술덧의 안전한 발효와 잡균오염을 방지하여 품질이 균일한 술을 생산할 목적으로 재래누룩과는 별도로 Aspergillus kawachii등의 균을 이용한 개량곡자(koji)가 술 제조시에 많이 이용되고 있으나 이러한 방법은 탁주의 대량생산과 수율은 증가시켰으나 다양한 품질이나 맛의 향상은 기대하기 어렵다. 본 실험은 재래누룩에서 분리된 곰팡이 10종과 대조균주로 Aspergillus kawachii CF1002 그리고 효모 Saccharomyces cerevisiae를 이용하여 술을 담금하여 그 제품의 headspace gas를 포집하여 GC/MS로 휘발성 향기성분을 분석하였으며 또한 관능평가를 실시하여 검토하였다. 각 균주별로 총 27∼40종의 향기성분이 확인되었으며 전체 시료에서 알콜(peak area% 52.3 9∼70.36%), 알칸류(3.49∼14.17%), 에스테르류(3.23∼7.37%), 유기산류(0∼2.85%), 알데히드류(0∼0.44%)의 순으로 함유량이 높은 것으로 나타났다. GC/MS를 통한 향기성분의 분석 결과 각각의 선발 균주로 제조된 술의 향기성분의 패턴이 서로 상이하였으며 이것은 통계분석에 의해 그 특징이 유의적으로 분석되어 Aspergillus sp. SH-607, Aspergillus sp. SH-613, Aspergillus sp. SH-667, Aspergillus sp. SH-696 그리고 Aspergillus sp. SH-412는 기호도가 높은 것으로 관찰되었다. 수집된 우수균주 10종과 Aspergillus kawachii등으로 담금하여 제조한 술 시료 11종류를 대상으로 하여 쓴맛, 미묘한 맛, 떫은 맛, 신맛, 좋은 맛의 정도를 5단계로 나누어 관능검사를 실시한 다음 자료를 Duncan's multiple range test로 분석한 결과 전체적으로 좋은 맛에 대한 기호도는 Aspergillus sp. SH-607 시료와 Aspergillus sp. SH-412, Rhizopus sp. SH-606, Aspergillus sp. SH-613, Rhizopus sp. SH-654, Aspergillus sp. SH-696 Aspergillus kawachii 시료가 유의성 있게 좋은 맛을 나타내 기호도가 높았으며 맛과 기호도가 가장 좋았던 것은 Aspergillus sp. SH-607 시료로 나타났다.

• Korean Journal of Food Science and Technology
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• v.26 no.3
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• pp.255-260
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• 1994

Four types of soybean paste(Doenjang), using traditional meju, koji, natto meju and mixture of koji and natto meju, were manufactured and fermented for 90 days. Analyzed volatile flavor components by GC-MS were confirmed to be thirty-six components including 5 alcohols, 5 aldehydes. 8 ketones, 3 acids, 9 esters and 6 miscellaneous ones. Traditional soybean paste tested had 29 components, koji and koji-natto soybean paste $26{\sim}24$ and natto soybean paste had 20 ones. Alcohol was found to be the most abundant volatile flavor components in all samples group. Traditional soybean paste had higher ratio of carbonyl to ester than any other types of soybean paste while koji-natto soybean paste had the lowest ratio of their components. The newly identified five volatile flavor components were 3-ethoxy-l-propene, dihydro-2-methyl-3-furanone. 1-hydroxy-2-propanone, 1-(2-furanyl)ethanone and 2-acethyl ethylhexanoate.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.921-927
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• 1995

Peach pulp was separated into serum and insoluble pulp by centrifugation at 11,000 rpm for 10 min. The serum portion was concentrated at $50{\sim}55^{\circ}C$ and $30{\sim}50\;mmHg$ with aroma recovery. Vapor generated at the early stage of vacuum evaporation was condensed and taken as aroma fractions: AR-1($0{\sim}5%$), AR-2($5{\sim}10$), AR-3($10{\sim}15%$), AR-4($15{\sim}20%$). Dynamic headspace concentration method was used to trap volatile compounds in aroma fractions and identification of aroma compounds was made by GC/MS. The yield of serum separated from peach pulp was 70.5% and the serum fraction contained the most of aroma compounds. Thirty-one aroma compounds, including ethylene, benzaldehyde, l-limonene and ${\gamma}-dodecalactone$ were identified. The efficiency of aroma recovery was reduced, as the recovery time was extended, as indicated by less peak numbers and peach areas of aroma fractions.

• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.591-607
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• 2020

This study was aimed to investigate the changes of chemical composition of the volatile organic compounds (VOCs) emitted from red pine needles in the process of needle abscission or senescence. The VOCs in intact, senescent, and litter red pine needle samples were analyzed by headspace-solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS). And then, multivariate statistical interpretation of the processed data sets was conducted to investigate similarities and dissimilarities of the needle samples. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to investigate the dataset structure and discrimination between samples, respectively. From the data preview, the levels of major components of VOCs from needles were not significantly different between needle samples. By PCA investigation, the data reduction according to classification based on the chlorophyll a / chlorophyll b (Ca/Cb) ratio were found to be ideal for differentiating intact, senescent, and litter needles. The following OPLS-DA taking Ca/Cb ratio as y-variables showed that needle samples were well grouped on score plot and had the significant discriminant compounds, respectively. Several compounds had significantly correlated with Ca/Cb ratio in a bivariate correlation analysis. Notably, the litter needles had a higher content of oxidized compounds than the intact needles. In summary, we found that chemical compositions of VOCs between intact, senescent, and litter needles are different each other and several compounds reflect characteristic of needle.

• 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 Korean Society on Water Environment
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• v.37 no.6
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• pp.510-519
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• 2021

Volatile Organic Compounds (VOCs) in sediments, which can cause human health problems, have been monitored in Korea since 2014. Measured VOC concentrations can be affected by matrix type and the volatility of target substances. In this study, (1) VOCs volatility and the influence of matrix interference were confirmed, and (2) internal standards (IS) method was applied to improve analytical method. For these purposes, method detection limit (MDL), calibration linearity, precision and accuracy of VOCs were compared in various matrices using the IS. Some of VOCs in sediments showed different peak areas and reduced rates compared to water matrix. It was suggested that adsorption properties of sediments hindered the migration to vapor during heat pretreatment in headspace method. A calibration curve was created in clean sand. Recovery rates for the calibration curve method and IS applying method were 64.1~83.1% and 99.1~119.3%, respectively. Relative standard deviations ranged from 11.1% to 21.6% for the calibration curve method and those for IS ranged 4.7% to 13.7%. In case of real sediment, calibration curve and 1,2-Dichlorobenzene-d4 (ODCB) among IS were not suitable. The average recovery rate of Fluorobenzene (FBZ) increased by 56.4% and Relative Standard Deviation (RSD) by 4.7%. However, the recovery rate was increased in the samples with large values of igniting intensity. This study confirmed that influence of the matrix of VOCs in sediment, and addition of IS materials improved precision and accuracy. Although IS corrects volatilization and adsorption, it is recommended that more than two types of IS should be added rather than single.