• Title/Summary/Keyword: ${GC}^1$

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Comparative Sampling Procedures for the Volatile Flavor Components of Codonopsis lanceolata (전처리 방법에 따른 더덕(Codonopsis lanceolata)의 휘발성 향기성분 비교 분석)

  • Kim, Jung-Han;Kim, Kyoung-Rae;Kim, Jae-Jung;Oh, Chang-Hwan
    • 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.

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Evaluation of Biogas Production Rate by using Various Electrodes Materials in a Combined Anaerobic Digester and Microbial Electrochemical Technology (MET) (미생물 전기화학 기술이 적용된 단일 혐기성소화조에서 전극재질에 따른 바이오가스 생성 효율 평가)

  • Shin, Wonbeom;Park, Jungyu;Lee, Beom;Kim, Yonggeun;Jun, Hangbae
    • Journal of Korean Society of Environmental Engineers
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    • v.39 no.2
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    • pp.82-88
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    • 2017
  • MET (Microbial Electrochemical Technology), such as MFC (Microbial Fuel Cell) and MEC (Microbial Electrolysis Cell), is a promising technology for producing sustainable biogas from an anaerobic digester (AD). At current stage, however, the most likely limiting factors, large internal resistances, should be overcome for successful scale up of this technology. Various researchers reported that application of electrode materials containing high current density, increase of ion strength and conductivity, configuration of electrode are good methods for minimizing internal resistances. Recently, stainless steel is receiving great attention because of not only high performance and durability but also low cost. Therefore, in this study, we evaluate electrochemical characteristics and biogas production rate using various electrode materials and configuration (graphite carbon coated with catalysts ($GC-C_M$) or not (GC), stainless steel mesh (SUS-M) and plate (SUS-P)). As the results, current densities of $GC-C_M$, GC, SUS-P, SUS-M were 2.03, 1.36, 1.04, $1.13A/m^2$, respectively. Methane yields of $GC-C_M$, GC, SUS-P, SUS-M were 0.27, 0.14, 0.19, 0.21 $L-CH_4/g-COD_{rem}$., respectively. Stainless steel shows high current density and methane yield, which are similar as graphite carbon coated with catalysts.

Comparative GC-MS Based In vitro Assays of 5α-Reductase Activity Using Rat Liver S9 Fraction

  • Lee, Su-Hyeon;Lee, Dong-Hyoung;Lee, Jeong-Ae;Lee, Won-Yong;Chung, Bong-Chul;Choi, Man-Ho
    • Mass Spectrometry Letters
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    • v.3 no.1
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    • pp.21-24
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    • 2012
  • $5{\alpha}$-Dihydrotestosterone (DHT) is the primary active metabolite of testosterone, catalyzed by $5{\alpha}$-reductase ($5{\alpha}R$) in the skin, prostate, and liver. In this study, the $5{\alpha}R$ activity in rat liver S9 fraction in the presence of a NADPH-generating system was evaluated and compared by gas chromatography-mass spectrometry (GC-MS)-based in vitro assays. Testosterone and a $5{\alpha}R$ inhibitor, finasteride, were added to the S9 fractions and incubated at $37^{\circ}C$ for 1 h. Both testosterone and DHT were quantitatively measured and compared with two different GC-MS-based steroid profiling techniques. DHT was not detected by conventional GC-MS analysis in the absence of finasteride when the concentration of testosterone in the S9 fraction was less than $0.2{\mu}M$, whereas the isotope-dilution GC-MS (GC-IDMS) system was able to evaluate the $5{\alpha}R$ activity. Because the S9 fraction contains more reactive enzymes and is easier to collect from tissues compared with a microsomal solution, the combination of the S9 fraction and GC-IDMS technique may be a promising assay for evaluating the $5{\alpha}R$ activity in large-scale clinical studies.

Analytical Methods of Levoglucosan, a Tracer for Cellulose in Biomass Burning, by Four Different Techniques

  • Bae, Min-Suk;Lee, Ji-Yi;Kim, Yong-Pyo;Oak, Min-Ho;Shin, Ju-Seon;Lee, Kwang-Yul;Lee, Hyun-Hee;Lee, Sun-Young;Kim, Young-Joon
    • Asian Journal of Atmospheric Environment
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    • v.6 no.1
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    • pp.53-66
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    • 2012
  • A comparison of analytical approaches for Levoglucosan ($C_6H_{10}O_5$, commonly formed from the pyrolysis of carbohydrates such as cellulose) and used for a molecular marker in biomass burning is made between the four different analytical systems. 1) Spectrothermography technique as the evaluation of thermograms of carbon using Elemental Carbon & Organic Carbon Analyzer, 2) mass spectrometry technique using Gas Chromatography/mass spectrometer (GC/MS), 3) Aerosol Mass Spectrometer (AMS) for the identification of the particle size distribution and chemical composition, and 4) two dimensional Gas Chromatography with Time of Flight mass spectrometry (GC${\times}$GC-TOFMS) for defining the signature of Levoglucosan in terms of chemical analytical process. First, a Spectrothermography, which is defined as the graphical representation of the carbon, can be measured as a function of temperature during the thermal separation process and spectrothermographic analysis. GC/MS can detect mass fragment ions of Levoglucosan characterized by its base peak at m/z 60, 73 in mass fragment-grams by methylation and m/z 217, 204 by trimethylsilylderivatives (TMS-derivatives). AMS can be used to analyze the base peak at m/z 60.021, 73.029 in mass fragment-grams with a multiple-peak Gaussian curve fit algorithm. In the analysis of TMS derivatives by GC${\times}$GC-TOFMS, it can detect m/z 73 as the base ion for the identification of Levoglucosan. It can also observe m/z 217 and 204 with existence of m/z 333. Although the ratios of m/z 217 and m/z 204 to the base ion (m/z 73) in the mass spectrum of GC${\times}$GC-TOFMS lower than those of GC/MS, Levoglucosan can be separated and characterized from D (-) +Ribose in the mixture of sugar compounds. At last, the environmental significance of Levoglucosan will be discussed with respect to the health effect to offer important opportunities for clinical and potential epidemiological research for reducing incidence of cardiovascular and respiratory diseases.

Volatile Components of Perillae folium (자소엽의 휘발성 성분)

  • Jang, Hee-Jin;Park, Jun-Young;Kim, Yong-Tae
    • Korean Journal of Food Science and Technology
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    • v.23 no.2
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    • pp.129-132
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    • 1991
  • The volatile components of Perillae folium were isolated by simultaneous steam distillation-extraction method, and analyzed by combined GC and GC-MS. Among seventeen components indentified 6 alcohols (3-octanol, 1-octen-3-ol, linalool, nerolidol, supathuleol and phytol), 2 ketones, 1 aldehyde, 1 phenol and 7 hydrocarbons were confirmed. The most abundant component was myristicin comprising about 53.4%.

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Determination of fungicides in wines by solid-phase extraction and gas chromatography with mass selective detection (고체상 추출법과 GC/MS를 이용한 포도주 중의 fungicides 정량)

  • Park, Gyo-Beom;Lee, Sueg-Geun
    • Analytical Science and Technology
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    • v.16 no.6
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    • pp.438-442
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    • 2003
  • The fungicides, used for grape growth and remained in the wine products from domestic and foreign countries such as vinclozolin, dichlofluanid, penconazole, procymidone were quantitatively analyzed after solid-phase extraction using a GC/MS-SIM method. The results obtained were as follows: for all the samples, the content of procymidone was in the range from 2.2 to $76.1{\mu}g/L$, recoveries 81.3-93.1 %, and standard deviation 1.4-3.4 %.

Volatile Components of Lycium chinensis Miller (구기자(Lycium chinensis Miller)의 휘발성 성분)

  • 박원종;복진영;백순옥;한상빈;주현균
    • The Korean Journal of Food And Nutrition
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    • v.10 no.1
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    • pp.1-5
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    • 1997
  • The volatile components of Lycium chinensis Miller were isolated by simultaneous steam distillation-extraction(SDE) method and analyzed by combined GC and GC-MS. Fifty-four volatile components, including 12 alcolhols 12 esters, 7 aldehydes, 6 acids, 5 ydrocarbons, 8 ketones, 1 furan and 3 pyrazines were confirmed in the fruit of Lycium chinensis Miller. The major components were hexadecanoic acid ethyl ester, 1-octadecanone, tetrapyrazine, 2-furancarboxaldehyde and ethyl linoleate.

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Identification of Biomarkers for Diagnosis of Gastric Cancer by Bioinformatics

  • Wang, Da-Guang;Chen, Guang;Wen, Xiao-Yu;Wang, Dan;Cheng, Zhi-Hua;Sun, Si-Qiao
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.4
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    • pp.1361-1365
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    • 2015
  • Background: We aimed to discover potential gene biomarkers for gastric cancer (GC) diagnosis. Materials and Methods: Genechips of 10 GC tissues and 10 gastric mucosa (GM, para-carcinoma tissue, normal control) tissues were generated using an exon array of Affymetrix containing 30,000 genes. The differentially expressed genes (DEGs) between GC tissues and normal control were identified by the Limma package and analyzed by hierarchical clustering analysis. Gene ontology (GO) and pathway enrichment analyses were performed for investigating the functions of DEGs. Receiver operating characteristics (ROC) analysis was performed to measure the effects of biomarker candidates for diagnosis of GC. Results: Totals of 896 up-regulated and 60 down-regulated DEGs were identified to be differentially expressed between GC samples and normal control. Hierarchical clustering analysis showed that DEGs were highly differentially expressed and most DEGs were up-regulated. The most significantly enriched GO-BP term was revealed to be mitotic cell cycle and the most significantly enriched pathway was cell cycle. The intersection analysis showed that most significant DEGs were cyclin B1 (CCNB1) and cyclin B2 (CCNB2). The sensitivities and specificities of CCNB1 and CCNB2 were both high (p<0.0001). Areas under the ROC curve for CCNB1 and CCNB2 were both greater than 0.9 (p<0.0001). Conclusions: CCNB1 and CCNB2, which were involved in cell cycle, played significant roles in the progression and development of GC and these genes may be potential biomarkers for diagnosis and prognosis of GC.

GC-MS Analysis of Chemical Constituents from Various Agarwood (GC-MS를 이용한 침향류의 성분 비교 연구)

  • Shin, Kwhang-Ho;Choi, Kyu-Yeol;Cho, Sung-Yong;Ahn, Duk-Kyun;Park, Seong-Kyu
    • The Korea Journal of Herbology
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    • v.26 no.1
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    • pp.7-12
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    • 2011
  • Objectives : The purpose of this study is to evaluate the quality of four different kinds of agarwood and analysis chemical constituents by GC-MS. Methods : Four source plants were two of Vietnamese agarwood, Indonesian agarwood and Myanmar agarwood. These plant materials were named sample No. 1-4. The chemical constituents of each agarwood were analysed by GC-MS. Results : GC-MS analysis showed that ${\beta}$-selinene was found in all the samples. The Vietnamese agarwood, Sample 1, and 4 has contained 6.861% and 7.497% of ${\beta}$-selinene and reached the highest level at the retention times 46.245 and 46.274 (min). Sample 2, the Myanmar agarwood has contained 1.608%, the lowest level of ${\beta}$-selinene, and it also has contained about 20% of ${\alpha}-,{\beta}-,{\gamma}$-eudesmol and 4.076% of valerianol. Sample 3, the Indonesian agarwood has contained 9.59% of ${\beta}$-selinene, 9.493% of ${\beta}$-selinene and shown its highest level (more than 19%) at the retention time 43.998 (min). Conclusion : It suggested that ${\beta}$-selinene could be a standard marker to evaluate agarwood by GC-MS analysis.

Prognostic Sub-Grouping of Diffuse Large B-Cell Lymphomas into Germinal Centre And Post Germinal Centre Groups by Immunohistochemistry after 6 Cycles of Chemotherapy

  • Hassan, Usman;Mushtaq, Sajid;Mamoon, Nadira;Asghar, Asghar Hussain;Ishtiaq, Sheeba
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1341-1347
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    • 2012
  • Introduction: Diffuse large B-cell lymphomas (DLBCL) can be divided into germinal centre (GC-DLBCL) and post germinal centre (post GC-DLBCL) groups by applying immunohistochemical antibodies. As these subgroups respond differently to chemotherapy, it is possible at diagnosis to select a poor prognostic subgroup for aggressive treatment. Objective: To determine the frequencies of GC-DLBCL and post GC-DLBCL in patients by immunohistochemistry (IHC) and the clinical response after six cycles of chemotherapy. Subjects and Methods: In this descriptive study conducted in AFIP and CMH, Rawalpindi and NORI, Islamabad, from September 2010 to September 2011, a total of 75 pretreatment cases of DLBCL diagnosed during the study period were included. Cases were segregated in to GC-DLBCL and post GC-DLBCL groups according to results of immunohistochemistry markers CD10, BCL6 and MUM1. Immediate clinical response was assessed after 6 cycles of chemotherapy. Response was divided into complete response, partial response, stable disease or relapse or progression. Results: The mean age was $54.2{\pm}15$. Males were 53 (70.7%). Forty (53.3%) cases comprised the GC-DLBCL group; 25(62.5%) of them showed a complete response. Most patients of the post GC-DLBCL 19(54%) showed relapse/progression. Results of immediate clinical response in both prognostic subgroups were significant (p<0.05). Results regarding positivity with immunohistochemical antibodies CD10 (p 0.011), BCL6 (p 0.013) and MUM1 (p 0.000) regarding immediate clinical response were also significant. Conclusion: GC-DLBCL group shows better response to CHOP chemotherapy regimen. Immunohistochemistry should be used to further classify DLBCL as this can enable us to select aggressive group for aggressive treatment. This manuscript is important because the study is the first to becarried out exclusively in Pakistan or our part of the world.