• Bulletin of the Korean Chemical Society
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• v.27 no.2
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• pp.231-236
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• 2006

A novel sample pretreatment technique, headspace hanging drop liquid phase microextraction (HS-LPME) was studied and applied to the determination of flavors from solid clove buds by gas chromatography-mass spectrometry (GC-MS). Several parameters affecting on HS-LPME such as organic solvent drop volume, extraction time, extraction temperature and phase ratio were investigated. 1-Octanol was selected as the extracting solvent, drop size was fixed to 0.6 $\mu$L. 60 min extraction time at 25 ${^{\circ}C}$ was chosen. HS-LPME has the good efficiency demonstrated by the higher partition equilibrium constant ($K_{lh}$) values and concentration factor (CF) values. The limits of detection (LOD) were 1.5-3.2 ng. The amounts of eugenol, $\beta$-caryophyllene and eugenol acetate from the clove bud sample were 1.90 mg/g, 1.47 mg/g and 7.0 mg/g, respectively. This hanging drop based method is a simple, fast and easy sample enrichment technique using minimal solvent. HSLPME is an alternative sample preparation method for the analysis of volatile aroma compounds by GC-MS.

• Mass Spectrometry Letters
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• v.13 no.4
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• pp.125-132
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• 2022

There are many types of spring blossoms on the Daedeok campus of Chungnam National University (CNU) at the area of 1,600,000 square meters. As an assignment for the class of Analytical Chemistry I for second-year undergraduate students, 2021, flower petals collected from various floral groups (Korean azalea, Korean forsythia, Dilatata lilac, Lilytree, Lily magnolia, and Prunus yedoensis) were analyzed using headspace extraction coupled to gas chromatography-mass spectrometry (HS-GC-MS) to study the aromatic profiles and fragrance compounds of each sample group. Various types of compounds associated with the aroma profiles were detected, including saturated alcohols and aldehydes (ethanol, 1-hexanol, and nonanal), terpenes (limonene, pinene, and ocimene), and aromatic compounds (benzyl alcohol, benzaldehyde). The different contribution of these compounds for each floral type was visualized using statistical tools and classification models based on principal component analysis with high reliability (R² = 0.824, Q² = 0.616). These results showed that HS-GC-MS with statistical analysis is a powerful method to characterize the volatile aromatic profile of biological specimens.

• 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.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.738-741
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• 2006

Volatile flavor compounds in commercial sterilized milk were analyzed and identified by static headspace, purge-and-trap, and solid-phase microextraction (SPME) methods. About 20 volatile compounds were identified by GC/MS, and aldehydes and ketones were the most distinctive and abundant compounds. Static headspace analysis allowed the identification of only the most abundant compounds, such as acetone. Five ketones (acetone, 2-butanone, 2-pentanone, 2-heptanone, 2-nonanone), four aldehydes (2-methylbutanal, pentanal, hexanal, benzaldehyde) and dimethyl sulfide, all of which were responsible for off-flavor in milk, were found by the purge-and-trap and SPME methods. The two methods differed little in their release of these compounds, but they yielded different amounts in the extraction.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.128-132
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• 2016

Volatile organic solvents are used to extract the bioactive materials from raw materials for environmentally-friendly farming materials (EFFM), but the solvent should not remain in EFFM for the safety reasons. Thus qualitative and quantitative analysis method for the solvents using Headspace-GC were evaluated. Water content depleted the detection ratio of hydrophilic solvents and disturbing the hydrophilic interaction with solvents by DMSO might be helped to increase the detection ratio (up to 715%). Surfactant concentration affected to the detection ratio (68.5-179.1%) while surfactant type was not deeply involved the solvent detection. On the other hand, matrix-matched calibration method was accepted the minimum requirements for the quantitative analysis of the solvents in EFFM.

• Food Science and Preservation
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• v.13 no.2
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• pp.269-272
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• 2006

Aroma compounds in chungkukjang with Astragalus membranaceus (Hwangki) were extracted by the simultaneous distillation and extraction (SDE), headspace and solid phase microextraction (SPME), and aroma compounds obtained by this method were identified with GC-MS. Thirty compounds were identified, including six ketones, eight alcohols, three heterocyclic compounds, three aldehydes, five hydrocarbones and five other compounds. Major aroma compounds were identified as 3-hydroxy-2-butanone, 2-furanmethanol, 2-methoxy-4-vinylphenol, and 4-vinylphenol in SDE, 2,3-butanedione, 3-hydroxy-2-butanone, ethanol, 2,6-dimethyl pyrazine and acetic acid in headspace and acetone, ethanol, 2,5-dimethyl pyrazine, tetramethyl pyrazine and acetic acid in SPME. The content of pyrazines identified in headspace and SPME methods was higher than that of SDE method, and the content of pyrazines containing 2,5-dimethyl pyrazine, 2,6-dimethyl pyrazine and tetramethyl pyrazine in chungkukjang was higher than that of Hwangki chungkukjang.

• Analytical Science and Technology
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• v.14 no.2
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• pp.109-114
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• 2001

The flavor-related compounds contained in tobacco were analyzed by selected ion monitoring (SIM) method using headspace SPME gas chromatography-mass spectrometry(GC-MS). Flavor-related compounds were estragole pulegone, trans-anethole, safrole, piperonal, eugenol, methyleugenol, coumarin, trans-isoeugenol, trans-methyleugenol and myristicin. More than on of the flavor-related compounds were detected in the range $0.001-1.3{\mu}g/g$ from all brands of tobacco studied. The recovery was ranged from 89.1 to 102.9% and relative standard deviation was ranged from 2.6 to 25.2%.

• Proceedings of the Ginseng society Conference
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• 2002.10a
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• pp.238-252
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• 2002

In order to screen out indicators for the discrimination of ginseng habitat, some physical and chemical characteristics of Korean red ginsengs (94 kinds) and Chinese red ginsengs (50 kinds) were analyzed by using a rheometer, an electronic nose system, a combined technique of solid phase micro-extraction (SPME) and gas chromatograph equipped with an electron capture detector (GC/ECD), an X-ray fluorescence spectrometer (XRF), an inductively coupled plasma mass spectrometer (ICP/MS), a near infrared spectrometer (NIRs) and high performance liquid chromatography equipped with evaporative light scattering detector (HPLC/ELSD). The results are summarized as follows: (i) The rhizome strengths of Korean red ginsengs were significantly higher than those of Chinese red ginsengs. (ii) The electronic nose patterns of Korean red ginsengs were significantly different from those of Chinese red ginsengs. (iii) Some unidentified peaks were detected not in the headspace of Korean red ginsengs but in the headspace of Chinese red ginsengs when the headspace volatiles prepared by the SPME technique were analyzed by GC/ECD. (iv) Either the content ratios of K to Ca or Mn to Fe were significantly different between Korean red ginsengs and Chinese red ginsengs. (v) The reflectance ratios of NIRs wavenumbers such as $904\;cm^{-1}\;to\;1088\;cm^{-1}$ for Korean red ginsengs were significantly different from those for Chinese red ginsengs. (vi) The content ratios of ginsenoside-Rg to ginsenoside-Re of Korean red ginsengs were significantly higher than those of Chinese red ginsengs. These results indicate that the rhizome strength, the electronic nose pattern, the occurrence of ECD-sensitive headspace volatile components, the content ratios of K to Ca and Mn to Fe, the NIRs pattern and the content ratio of ginsenoside-Rg to -Re may be indicators for the discrimination of ginseng habitat.

• The Korean Journal of Food And Nutrition
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• v.17 no.3
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• pp.260-265
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• 2004

Volatile components of pine needle(Pinus densiflora S.) were isolated by purge & trap headspace technique and analyzed by gas chromatography-mass spectrometry(GC-MS). And then volatile components were extracted for 2 hr and 20 hr at the two different temperature settings: room temperature and 60$^{\circ}C$. A total of 61 volatile components were identified by the four different conditions. These compounds are classified into six categories in terms of chemical functionality: 35 hydrocarbons, 16 alcohols, 4 carbonyls, 2 esters, 1 acid and 3 ethers. The major components were ${\alpha}$-pinene(1.5～15.7%), ${\beta}$-myrcene(13.2～15.6%), ${\beta}$-phellandrene(l2.0～16.0%) and cis-3-hexenol(4.0～18.3%). In the comparison of the four extraction conditions, longer extraction can be effective to extract components that have a high boiling point, but proved useless in obtaining low boiling point components. As a result of these experiments under the four different conditions, the 20 hr extraction at room temperature appeared to be the most optimized condition for the analysis of volatile compounds by using the purge & trap headspace technique.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.171-176
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• 1992

Volatile flavor components of Codonopsis lanceolata were extracted by gas co-distillation (GCD), solvent extraction/fractionation (SEF), and headspace sampling (HSS) methods. The extracts were analyzed by dual-capillary gas chromatography-retention index (GC-RI) and gas chromatography-mass spectrometry(GC-MS). The two extracts prepared by SEF and HSS gave more similar fragrance to the Codonopsis lanceolata than the GCD extract. The GC profiles of the SEF and HSS extracts were similar to each other except for differences in peak areas. The extract prepared by SEF gave a sweet note while the extract prepared by HSS gave a green note. The GCD extract began to give a burnt note of herb medicine with prolonged distillation. Rapid extraction of flavor components from Codonopsis lanceolata was possible in several short steps by SEF and HSS methods compared to GCD. GC-MS and GC-RI were used for peak identification. GC-RI was more effective for identification of isomers, and polar FFAP column was more suitable for identification of polar compounds. From Codonopsis lanceolata we identified 35 volatile flavor constituents, 24 of which have not been previously reported by simultaneous distillation extraction method $^{(5)}$. trans-2-Hexanal, cis-3-hexen-1-ol, trans-2-hexen-1-ol, and hexanol were considered key components of the green note and 1-octen-3-ol, the component of the fresh note. Esters, including amyl propionate, seem to be responsible for the sweet note particular to Codonopsis lanceolata.