• Bulletin of the Korean Chemical Society
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• 제35권1호
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• pp.211-217
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• 2014

A new needle-based device for headspace wire coated in-needle microextraction (HS-WC-INME) was fabricated using a nichrome wire coated with poly(ethylene glycol) (PEG) and poly(dimethylsiloxane) (PDMS) mixture. The proposed needle device was applied for the determination of volatile compounds in lavender and lavandin essential oils by gas chromatography. Fundamental parameters such as needle design, conditions of extraction and desorption were optimized along with the validation of the extraction and desorption efficiency. The optimal conditions were 30 min extraction at $50^{\circ}C$ and 2 min desorption at $240^{\circ}C$. The calibration curves showed good linearity with the suitable values of the coefficients of determination ($r^2$) greater than 0.99. The limits of detection for linalyl acetate, ${\beta}$-caryophyllene, linalool and (+)-limonene were 7.15, 9.04, 10.79 and 22.26 ng, respectively. Analytical recoveries were acceptable in the test samples, varying from 86.7% to 108.0%. The values of relative standard deviations for run to run showed range less than 0.9% while 3.9% through 7.2% for needle to needle. The proposed PEG-PDMS coating could be more suitable than PDMS coating to extract particular polar groups such as alcohols.

• 분석과학
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• 제33권2호
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• pp.76-85
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• 2020

A stainless-steel needle (Hamilton 90022, 22 gauge, 718-㎛ o.d., 413-㎛ i.d., 51-mm length, bevel tip) with an electrochemically coated polyaniline layer having a microbore tunnel was newly prepared as a device for headspace in-needle microextraction. For designing the needle, the polyaniline layer length was optimized, and to evaluate the extraction efficiency for polycyclic aromatic hydrocarbons, numerous cyclic voltammetry scans were conducted. In addition, the optimization of the analytical conditions (including the adsorption and desorption parameters) and the validation of the analytical method were conducted. The optimized adsorption and desorption conditions were 40 ℃ for 30 min and 230 ℃ for 60 s, respectively. Finally, in this study, a polyaniline layer was electrochemically deposited on the in-needle surface, and it exhibited good thermal stability. The needle with the polyaniline layer was repeatedly used more than 200 times during this study. This method has some advantages in terms of the extraction time, extraction efficiency, and analysis cost.

• 분석과학
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• 제33권3호
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• pp.167-167
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• 2020

• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1703-1707
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• 2013

A fast and simple sampling and sample preparation device, (NTD) has been developed and applied to sample and analyze volatile components from ground coffee beans. Coffee fragrances and other volatile organic compounds (VOCs) were sampled by the NTD and then analyzed by gas chromatograph-mass spectrometry (GC/MS). Divinylbenzene (DVB) particles (80/100 mesh size) were the sorbent bed of the NTD. More than 150 volatile components were first identified based on the database of the mass library and then finally 30 fragrances including caffeine were further confirmed by comparing experimental retention indices (i.e. Kovat index) with literature retention indices. Total sampling time was 10 minutes and no extra solvent extraction and/or reconstitution step need. Straight n-alkanes (C6-C20) were used as retention index probes for the calculation of experimental retention indices. In addition, this report suggests that an empty needle can be an alternative platform for analyzing polymers by pyrolysis-GC/MS.

• Journal of the Korean Wood Science and Technology
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• 제48권5호
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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.

• 한국식품영양학회지
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• 제19권2호
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• pp.161-168
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• 2006

식물체의 향기성분을 분리하는데 주로 사용되는 headspace(DHS, RPHS)법, SPME법, SDE법, SFE법과 최근에 개발된 PDE법으로 솔잎의 휘발성 성분을 추출하였다. 추출된 성분을 Ge/MS를 이용하여 총 65종의 휘발성 성분을 확인하였다. 확인된 성분은 terpene류 25종, alcoholfb류 16종, carbonyls류 9종, esters류 6종, acids류 7종, esters 화합물이 2종인 것으로 나타났다. Headspace(DHS, RPHS)법과 SPME 법에서는 휘발성이 강한 ethyl acetate, 2-ethyl furan, $\beta$-myrcene 등과 같은 저비점 휘발성 성분들이 많이 추출되었다. 반면에, 고비점 휘발성 성분들인 nerolidol, spathulenol, benzoic acid 등은 휘발 성분 추출시 열이 가해지는 SDE법, SFE법, PDE법 등에서는 확인되었으나 headspace법과 SPME법에서는 확인되지 않았다. 이들 6가지 추출방법에서 저비점 휘발성 성분 분석에는 headspace(DHS)법이 가장 좋은 것으로 나타났으며, 고비점 휘발성 성분 분석에는 SDE법이 가장 적합한 것으로 나타났다. 최근에 개발된 PDE법은 SDE법에 비해 추출효율 변에서 약간 떨어지나 전처리 방법이 간단하므로 짧은 시간에 많은 시료를 분석할 때 가장 적합한 방법인 것으로 판단된다.

• 한국식품과학회지
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• 제37권4호
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• pp.525-531
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• 2005

본 연구에서는 원료 첨가(오가피, 영지버섯, 솔잎 및 홍삼)를 달리하여 오가피주를 제조하여 영양성분 및 휘발성 향기성분을 분석하였고 기타 주류의 품질요인에 관여하는 요인들을 평가하고 관능검사를 수행함으로서, 제조한 오가피주의 다양한 품질 평가를 수행하여 민속주로의 개발 가능성을 평가하였다. 주정도는 오가피 및 기타의 기능성 소재의 함량을 달리한 4가지 시료에서 각각 14.5-15.3%로 큰 차이를 볼 수는 없었다. 총 유기산 함량은 오가피주가 일반 약주 보다 훨씬 많은 양이 검출되었으며 반면 오가피 및 기타 기능성 소재를 첨가한 시료에서 citric acid와 tartaric acid는 오히려 약간 양이 감소한 것으로 보여졌다. 오가피주의 유리아미노산 함량은 histidine이 가장 많았으며, 총 유리아미노산 및 유리당 함량은 시료 C에서 가장 높게 나타났다. 시료 A 및 B에서는 총 49종의 휘발성 향기성분이 동정되었고 시료 C와 D에서는 각각 48 및 31종의 성분이 동정되었다. 무첨가군인 시료 D의 경우 alcohol류의 함량이 다른 군에 비해 높게 보여졌으며 ethanol의 함량이 79.59%로, iso-butyl alcohol이 0.35%로 다른 군에 비해 높게 보여졌다. 오가피, 영지버섯, 솔잎 및 홍삼이 함유된 시료 A, B, 및 C에서는 다양한 종류의 테르펜 화합물이 확인되었다. 이는 주류 고유의 향기성분 외에 첨가된 오가피, 영지버섯, 솔잎 및 홍삼에 의해 더욱 다양한 향기성분이 나타난 것으로 생각되는데, 특히 ${\alpha}-copaene$의 함량이 시료 D에서보다 A, B 및 C에서 2배 이상 높게 다량 확인되었다. GC-O를 이용하여 향기성분을 관능적으로 동정한 결과 기능성 소재의 배합 비율에 따라 소비자가 느끼는 관능적 특성은 상당히 유동적으로 변할 수 있음을 확인할 수 있었다. 오가피 함량이 높은 술일수록 명도가 높아 밝고 황색도가 낮아지는 경향을 볼 수 있었고, 오가피를 0.1%첨가한 오가피주가 좋은 맛과 감칠맛에서 유의적으로 높은 것으로 평가되었다.