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- 검색키워드
- 주제어 : Derivatization (검색결과 180 건)
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Park, N.H.,Hong, J.Y.,Shin, H.J.,Hong, J. Elsevier 2013 Journal of chromatography A Vol.1305 No.-
A comprehensive analytical method was developed for the profiling of biogenic amines in human urine using GC/MS in SIM mode. Biogenic amines and their acidic metabolites were converted into their volatile O-trimethylsilyl/N-heptafluorobutyryl (OTMS/-NHFBA) derivatives for GC/MS analysis. Dual hexamethyldisilazane (HMDS)/-N-methyl-bis-heptafluorobutyramide (MBHFBA) derivatizations have been shown to be quite effective, with high derivatization yields and the absence of side products for primary biogenic amines. In this study, selective derivatization conditions by HMDS/MBHFBA were optimized in terms of the reagent amount, reaction temperature and reaction time period. The highest derivatization reaction yield was obtained at 40<SUP>o</SUP>C for 10min for OTMS derivatization and 80<SUP>o</SUP>C for 5min for N-HFBA derivatization. The use of MCX SPE cartridges with different SPE elution solvents was effective for the pre-concentration and selective cleanup of the biogenic amines and their acidic metabolites in human urine. The selection of appropriate ions in SIM mode provided reliable quantification and identification and a reduction in background effects. The established method was validated in terms of linearity, limits of detection (LOD), limits of quantification (LOQ), precision, and accuracy. The present method was linear (r<SUP>2</SUP>>0.996), reproducible (relative standard deviation range 1.1-6.9%), and accurate (range 87.9-111.9%), with LOQs of 0.17-17.84ng/mL. The biogenic amine profiling of human urine was successfully accomplished by GC/MS in SIM mode combined with selective HMDS/MBHFBA derivatization and MCX SPE cleanup.
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Determination of the PDE-5 Inhibitors and Their Analogues by GC-MS and TMS Derivatization
Jaesung Pyo,Heesang Lee,Yujin Park,Jiyeong Jo,Yonghoon Park,Sanggil Choe,Miyoung Lee,Jaesin Lee 사단법인 한국질량분석학회 2012 Mass spectrometry letters Vol.3 No.1
Eighteen of the PDE-5 inhibitors and their analogues were analyzed using GC-EI-MS. Fourteen of them could beidentified by simple GC-MS method without derivatization, but hydroxyhongdenafil, hydroxyvardenafil, xanthoanthrafil andmirodenafil could not be identified without derivatization for the high polarity due to the presence of hydroxyl groups. N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), widely used trimethylsilyl (TMS) derivatizing reagents, were used to improve the sensitivity of the hydroxylated analogues. And the analytes could be identified by GC-MS after the derivatization. Eighteen of the PDE-5 inhibitors and their analogues were analyzed using GC-EI-MS. Fourteen of them could beidentified by simple GC-MS method without derivatization, but hydroxyhongdenafil, hydroxyvardenafil, xanthoanthrafil andmirodenafil could not be identified without derivatization for the high polarity due to the presence of hydroxyl groups. N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), widely used trimethylsilyl(TMS) derivatizing reagents, were used to improve the sensitivity of the hydroxylated analogues. And the analytes couldbe identified by GC-MS after the derivatization.
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Minseon Kim,Donghao Li,Won-Joon Shim,Jae-Ryoung Oh,Jongman Park* 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.3
Environmentally important phthalic esters have been analyzed by GC-MS in terms of individual phthalic esters or total phthalic esters directly or after derivatization. Derivatization improves the chromatographic characteristics of the highly polar phthalic esters. This study focused on the GC-MS determination of the total phthalic esters and the individual phthalic esters simultaneously. The phthalic esters were hydrolyzed to phthalate and corresponding alcohols in 1 M NaOH solution at 90 oC for 30 min followed by extraction with ethyl acetate after acidifcation. The phthalic acid and alcohols were simultaneously silyl derivatized using bis(trimethylsilyl)trifluoroacetamide (BSTFA) to their corresponding silyl ester and ethers in the mixture of 60% acetone and 40% ethyl acetate at room temperature within 30 min. Because of the high reactivity of BSTFA with the phthalic acid and alcohols effective silyl derivatization was possible simultaneously. GC-MS analysis of the silyl derivatives of phthalic acid and alcohols was performed. The total phthalic ester content was estimated from the analytical result of phthalic silyl ester, while the individual phthalic ester was quantified from the analytical results of alcoholic silyl ethers. This technique was applied to spiked tab water and real seawater samples from the Lake Shihwa in Korea. The results were checked against the results from the direct GC-MS analysis of the phthalic esters and reasonable recoveries with high sensitivity were achieved. The recoveries were higher than 75% with low relative standard deviation (below 10%).
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Kim, Min-Seon,Li, Dong-Hao,Shim, Won-Joon,Oh, Jae-Ryoung,Park, Jong-Man Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.3
Environmentally important phthalic esters have been analyzed by GC-MS in terms of individual phthalic esters or total phthalic esters directly or after derivatization. Derivatization improves the chromatographic characteristics of the highly polar phthalic esters. This study focused on the GC-MS determination of the total phthalic esters and the individual phthalic esters simultaneously. The phthalic esters were hydrolyzed to phthalate and corresponding alcohols in 1 M NaOH solution at 90 oC for 30 min followed by extraction with ethyl acetate after acidifcation. The phthalic acid and alcohols were simultaneously silyl derivatized using bis(trimethylsilyl)trifluoroacetamide (BSTFA) to their corresponding silyl ester and ethers in the mixture of 60% acetone and 40% ethyl acetate at room temperature within 30 min. Because of the high reactivity of BSTFA with the phthalic acid and alcohols effective silyl derivatization was possible simultaneously. GC-MS analysis of the silyl derivatives of phthalic acid and alcohols was performed. The total phthalic ester content was estimated from the analytical result of phthalic silyl ester, while the individual phthalic ester was quantified from the analytical results of alcoholic silyl ethers. This technique was applied to spiked tab water and real seawater samples from the Lake Shihwa in Korea. The results were checked against the results from the direct GC-MS analysis of the phthalic esters and reasonable recoveries with high sensitivity were achieved. The recoveries were higher than 75% with low relative standard deviation (below 10%).
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김신혜,장현준,박정향,이형준,김정권,임용현,김단비,윤소희 한국물리학회 2017 Current Applied Physics Vol.17 No.8
Mass spectrometry (MS) with low temperature plasma (LTP) as an ionization source is one of the widely used ambient methods in analyzing various bio-chemical samples for their detection, identification, differentiation, etc. While the LTP-MS allows selective analysis of a sample with low-molecular weight without thermal damages, it has difficulties desorbing a target molecule from the sample surface with a low volatility. Hence, for the purpose of enhancing the desorption and ionization efficiencies of the LTPMS when analyzing the fatty acids, two methods were compared: directly heating the sample surface and increasing the vapor pressure of the fatty acid itself by derivatization. In addition, the fatty acids in Drosophila were directly analyzed with the LTP-MS. As a result, it was found that the LTP-MS detection efficiency was enhanced with the derivatization as much as with the heating condition while there was little synergy in employing both of the heating and derivatization together.
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Kim, S.H.,Jang, H.J.,Park, J.H.,Lee, H.J.,Kim, J.,Yim, Y.H.,Kim, D.B.,Yoon, S. Elsevier 2017 Current Applied Physics Vol.17 No.8
<P>Mass spectrometry (MS) with low temperature plasma (LTP) as an ionization source is one of the widely used ambient methods in analyzing various bio-chemical samples for their detection, identification, differentiation, etc. While the LTP-MS allows selective analysis of a sample with low-molecular weight without thermal damages, it has difficulties desorbing a target molecule from the sample surface with a low volatility. Hence, for the purpose of enhancing the desorption and ionization efficiencies of the LTP-MS when analyzing the fatty acids, two methods were compared: directly heating the sample surface and increasing the vapor pressure of the fatty acid itself by derivatization. In addition, the fatty acids in Drosophila were directly analyzed with the LTP-MS. As a result, it was found that the LTP-MS detection efficiency was enhanced with the derivatization as much as with the heating condition while there was little synergy in employing both of the heating and derivatization together. (C) 2017 Elsevier B.V. All rights reserved.</P>
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Determination of the PDE-5 Inhibitors and Their Analogues by GC-MS and TMS Derivatization
Pyo, Jae-Sung,Lee, Hee-Sang,Park, Yu-Jin,Jo, Ji-Yeong,Park, Yong-Hoon,Choe, Sang-Gil,Lee, Mi-Young,Lee, Jae-Sin Korean Society for Mass Spectrometry 2012 Mass spectrometry letters Vol.3 No.1
Eighteen of the PDE-5 inhibitors and their analogues were analyzed using GC-EI-MS. Fourteen of them could be identified by simple GC-MS method without derivatization, but hydroxyhongdenafil, hydroxyvardenafil, xanthoanthrafil and mirodenafil could not be identified without derivatization for the high polarity due to the presence of hydroxyl groups. N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) and N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), widely used trimethylsilyl (TMS) derivatizing reagents, were used to improve the sensitivity of the hydroxylated analogues. And the analytes could be identified by GC-MS after the derivatization.
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Won-Suk Song,Han-Gyu Park,Seong-Min Kim,Sung-Hyun Jo,Byung-Gee Kim,Ashleigh B. Theberge,Yun-Gon Kim 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.83 No.-
Short chain fatty acids (SCFAs) are end products of fermentation by anaerobic gut microbiota. They can beused as beneficial metabolites to regulate the host’s physiological processes. Despite their importance,SCFAs are difficult to analyze with mass spectrometric technologies due to their poor ionizationefficiency and susceptibility to water loss during ionization of low molecular weight organic acids. Here,we developed a sensitive and reliable method to quantify SCFAs by liquid chromatography tandem massspectrometry (LC–MS/MS) in multiple reaction monitoring (MRM) mode. SCFAs were chemicallyderivatized by Girard’s reagent T (GT), providing a permanent cationic charge. This techniquedemonstrated an excellent quantitative capacity, showing good linearity (R2> 0.99) and limit ofquantification (femtomole levels) forfive SCFAs (i.e., acetate, propionate, butyrate, valerate, andcaproate). Next, we applied this derivatization method to quantitate SCFAs from a small volume of totalextracellular metabolites produced by Eubacterium rectale (E. rectale), one of main butyrate-producinggut bacteria. GT-labeled SCFAs were quantitated well in small volumes of culture medium (5, 10, 15, and20 mL), with the amount of SCFA measured being proportional to the volume of culture medium, asexpected. We also investigated plant-derived polysaccharides as prebiotics that could enhance theproduction of butyrate by E. rectale. Finally, the production of butyrate was successfully monitored in aco-culture system for E. rectale and Bifidobacterium longum (B. longum) by analyzing GT-labeled butyrate. Taken together, our results suggest that this highly sensitive method would be useful for quantifyingSCFAs extracted from stool in an aqueous solution to monitor gut health.
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Yoon, Hong-Tak,Yoo, Hwan-Soo,Shin, Bum-Kyu,Lee, Woo-Jin,Kim, Hwan-Mook,Hong, Seon-Pyo,Moon, Dong-Cheul,Lee, Yong-Moon The Pharmaceutical Society of Korea 1999 Archives of Pharmacal Research Vol.22 No.3
Precolumn orthophthaldehyde (OPA) labeling method of sphingoid bases, sphingosine and sphinganine, was investigated to obtain high fluorescent detectability. In order to improve the fluorescent yield, we investigated the optimal solubility of sphingoid bases for five pre-incubation solvents by incorporating the heating procedure before OPA derivatization. The pre-incubation in ethanol prominently increased the fluorescent peak height of OPA derivative for each sphingoid bases in high performance liquid chromatography. About tenfold increase of detectability was archived by pre-incubating lipid extracts pellets in ethanol at $60^{\circ}C$ for 30 min. Optimal derivatization was performed in 30 min at ambient temperature and the fluorescent intensity of OPA derivative was stable for two weeks at $4^{\circ}C$. The detection limit of sphingosine was 0.1 pmol as injected amount. This method was applied to the determination of cellular sphingosine and sphinganine in various human lung cancer cells. This OPA procedure was prospective to be useful for quantitating the amount of sphingoid bases in other cancer cells.
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Pseudoephedrine과 유도체화 시약의 TLC상 직접반응과 이미지 분석을 통한 검출한계 및 반정량분석법에 관한 선행평가
김현태,이상순,최성운 한국과학수사학회 2014 과학수사학회지 Vol.8 No.4
Pseudoephedrine (PSE) is the critical chemical precursor involved in the illegal production ofmethamphetamine. A preliminary test for the rapid and easy identification and semi-quantitative determinationof PSE was performed. PSE derivatives generated from direct reaction (in situ ,co-spot) of PSE with derivatizing reagents were identified and used to determine the LOD. The TLC images were analyzed with densitometric image analysis programs to determine the repeatability and linearity of derivatization reaction for a potential semi-quantitative analysis. PSE was reacted in situ (co-spot) to evaluate their derivatization reactivity in the pre-column mode on a silica gel TLC plate with FMOC-Cl, Dansyl-Cl or Dabsyl-Cl as derivatizing reagents. The derivatized products were identified under naked eyes with or without UV light and the TLC image analysis of corresponding spots was performed using the densitometric image analysis for the semi-quantitative evaluation. All the derivatizing reagents generated compounds containing strongly visible or UV-absorbing FMOC-, Dansyl- and Dabsyl- groups on the TLC plate after reacting with PSE. However, a different reactivity of PSE with the reagents was observed. In the experiment using FMOC-Cl (reaction spots exposed with air at room temperature for 10 min.) and Dansyl-Cl (reaction spots covered with glass plate while heated at 70 oC for 10 min.), the LODs (Limit of detection, 2 μL/spot, mg/mL) of PSE was in the low concentration range of 0.001 ~ 0.005, but the higher LOD concentration of 0.25 was found when Dabsyl-Cl was used even when the reaction spots were covered and heated. The RSD value (average, %) to test the repeatability of the derivatization reaction for PSE (0.5 mg/mL) was in the range of 2.14 ~ 2.27% when FMOC-Cl used. But a high RSD value range of 5.87 ~ 6.20% was shown at the low concentration (0.1 mg/mL) of PSE. Also at two concentrations (0.5 mg/mL and 0.05 mg/mL) of PSE with Dansyl-Cl, the high RSD value range of 4.63 ~ 5.61% was found. In the test of the linearity (R2) of the derivatization reaction at a high concentration range (0.1 ~ 1.0 mg/mL) of PSE with FMOC-Cl and Dansyl-Cl, a relatively good correlation was shown to be in the range of 0.96 ~ 0.98 between the areas of spots of generated derivatives and concentration of PSE. However, the R2 values calculated from the concentration of the LOD of PSE up to a high concentration (1mg/mL) of PSE was dropped into the range of 0.90 ~ 0.92. The current method generated three derivatives with rather low repeatability and provided a way to improve the LOD of PSE to 160 ~ 1000 times compared to the TLC method of underivatized PSE. To demonstrate the validity of the current method to be used for a semi-quantitative analysis of PSE by showing the high repeatability of a derivatization reaction at various concentration of PSE, additional experimental results are required such as the various changes of the concentration of derivatization reagents, the usage of other reaction solvent, changes of reaction temperature, etc.
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