The authors would like to acknowledge the financial support of this project by The J.M. Smucker company.

<ol>
	<li>Ara&#250;jo, W. L., Nunes-Nesi, A., Nikoloski, Z., Sweetlove, L. J., Fernie, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Metabolic+Control+and+Regulation+of+the+Tricarboxylic+Acid+Cycle+in+Photosynthetic+and+Heterotrophic+Plant+Tissues:+TCA+Control+and+Regulation+in+Plant+Tissues.">Metabolic Control and Regulation of the Tricarboxylic Acid Cycle in Photosynthetic and Heterotrophic Plant Tissues: TCA Control and Regulation in Plant Tissues.</a> Plant Cell Environ. 35 (1), 1-21 (2012).</li><li>Finkemeier, I., Konig, A. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transcriptomic+Analysis+of+the+Role+of+Carboxylic+Acids+in+Metabolite+Signaling+in+Arabidopsis+Leaves.">Transcriptomic Analysis of the Role of Carboxylic Acids in Metabolite Signaling in Arabidopsis Leaves.</a> Plant Physiol. 162 (1), 239-253 (2013).</li><li>Doyle, M. P., Buchanan, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Food Microbiology: Fundamentals and Frontiers. , (2013).</li><li>T&#367;ma, P., Samcov&#225;, E., &#352;tul&#236;k, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+the+Spectrum+of+Low+Molecular+Mass+Organic+Acids+in+Urine+by+Capillary+Electrophoresis+with+Contactless+Conductivity+and+Ultraviolet+Photometric+Detection-An+Efficient+Tool+for+Monitoring+of+Inborn+Metabolic+Disorders.">Determination of the Spectrum of Low Molecular Mass Organic Acids in Urine by Capillary Electrophoresis with Contactless Conductivity and Ultraviolet Photometric Detection-An Efficient Tool for Monitoring of Inborn Metabolic Disorders.</a> Anal Chim Acta. 685 (1), 84-90 (2011).</li><li>L&#243;pez-Bucio, J., Nieto-Jacobo, M. F., Ram&#305;&#769;rez-Rodr&#305;&#769;guez, V., Herrera-Estrella, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organic+Acid+Metabolism+in+Plants:+From+Adaptive+Physiology+to+Transgenic+Varieties+for+Cultivation+in+Extreme+Soils.">Organic Acid Metabolism in Plants: From Adaptive Physiology to Transgenic Varieties for Cultivation in Extreme Soils.</a> Plant Sci. 160 (1), 1-13 (2000).</li><li>Cebolla-Cornejo, J., Valc&#225;rcel, M., Herrero-Mart&#236;nez, J. M., Rosell&#242;, S., Nuez, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+Efficiency+Joint+CZE+Determination+of+Sugars+and+Acids+in+Vegetables+and+Fruits:+CE+and+CEC.">High Efficiency Joint CZE Determination of Sugars and Acids in Vegetables and Fruits: CE and CEC.</a> Electrophoresis. 33 (15), 2416-2423 (2012).</li><li>Rosello, S., Galiana-Balaguer, L., Herrero-Martinez, J. M., Maquieira, A., Nuez, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+Quantification+of+the+Main+Organic+Acids+and+Carbohydrates+Involved+in+Tomato+Flavour+Using+Capillary+Zone+Electrophoresis.">Simultaneous Quantification of the Main Organic Acids and Carbohydrates Involved in Tomato Flavour Using Capillary Zone Electrophoresis.</a> J Sci Food Agr. 82 (10), 1101-1106 (2002).</li><li>Wasielewska, M., Banel, A., Zygmunt, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capillary+Electrophoresis+in+Determination+of+Low+Molecular+Mass+Organic+Acids.">Capillary Electrophoresis in Determination of Low Molecular Mass Organic Acids.</a> Int J Environ Sci Dev. 5 (4), 417-425 (2014).</li><li>Galli, V., Garc&#236;a, A., Saavedra, L., Barbas, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capillary+Electrophoresis+for+Short-Chain+Organic+Acids+and+Inorganic+Anions+in+Different+Samples.">Capillary Electrophoresis for Short-Chain Organic Acids and Inorganic Anions in Different Samples.</a> Electrophoresis. 24 (1213), 1951-1981 (2003).</li><li>Klampfl, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+Organic+Acids+by+CE+and+CEC+Methods.">Determination of Organic Acids by CE and CEC Methods.</a> Electrophoresis. 28 (19), 3362-3378 (2007).</li><li>Kenney, B. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Determination+of+Organic+Acids+in+Food+Samples+by+Capillary+Electrophoresis.">Determination of Organic Acids in Food Samples by Capillary Electrophoresis.</a> J Chromatogr A. 546, 423-430 (1991).</li><li>Galli, V., Barbas, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capillary+Electrophoresis+for+the+Analysis+of+Short-Chain+Organic+Acids+in+Coffee.">Capillary Electrophoresis for the Analysis of Short-Chain Organic Acids in Coffee.</a> J Chromatogr A. 1032 (1-2), 299-304 (2004).</li><li>Schmitt-Kopplin, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capillary+Electrophoresis:+Methods+and+Protocols.">Capillary Electrophoresis: Methods and Protocols.</a> Methods in Molecular Biology. , 384 (2008).</li><li>Nollet, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Chromatographic analysis of the environment 3rd ed. , (2006).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> ElixerOA Organic Acids/Anions Operating and Instruction Manual, MicroSolv Technology Corperation. , (2001).</li><li>Dahlen, J., Hagberg, J., Karlsson, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+low+molecular+weight+organic+acids+in+water+with+capillary+zone+electrophoresis+employing+indirect+photometric+detection.">Analysis of low molecular weight organic acids in water with capillary zone electrophoresis employing indirect photometric detection.</a> Fresenius J. Anal. Chem. 366 (5), 488-493 (2000).</li><li>Ibanez, A. B., Bauer, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analytical+method+for+the+determination+of+organic+acids+in+dilute+acid+pretreated+biomass+hydrolysate+by+liquid+chromatography-time-of-flight+mass+spectroscopy.">Analytical method for the determination of organic acids in dilute acid pretreated biomass hydrolysate by liquid chromatography-time-of-flight mass spectroscopy.</a> Biotech. For Biofuels. 7 (145), (2014).</li></ol>

The authors declare that they have no competing financial interests.

임의의 분석 기법으로 크게 발생되는 데이터의 품질과 신뢰성에 영향을 미칠 수있는 여러 가지 중요한 요소가있다. 첫째, 냉동 / 해동 사이클을 최소화하여, 샘플을 효율적으로 처리하는 것이 중요하다. 반복 된 동결 융해 처리 또는 분석 전에 샘플의 화학 성분을 손상시킬 수있다. 둘째, 일관되고 균일 모든 샘플이 프로토콜의 단계를 적용하는 것이 중요하다. 일관성 샘플 준비 및 처리 기술에서 ...

Carboxylic acids are organic compounds containing one or more terminal carboxyl functional groups, each attached to an R-group containing one or more carbons (R-C[O]OH). Short chain, low molecular weight carboxylic acids (short chain carboxylic acids, SCCAs) containing between one and six carbons, are essential components of cellular respiration, and function in several biochemical pathways necessary for cell growth and development. SCCAs play critical roles in cellular metabolism1, cell signaling2, and organismal responses to the environment (such as antibiosis3). Because of this, SCCAs can serve as useful indicators of disruptions to cellular metabolism, plant stress responses4,5, and fruit quality6,7. To date, SCCAs have been quantified primarily through chromatographic techniques such as high performance liquid chromatography (HPLC) or gas chromatography-mass spectroscopy (GC-MS). While these methods, are capable of achieving very low limits of detection, they can be expensive, require the derivatization of target SCCAs using caustic and/or toxic reagents, and include lengthy separation runs on the GC or HPLC. Because of this, interest in the use of free zonal capillary electrophoresis (CZE), which does not require sample derivatization, to quantify organic acids has steadily increased8.
Free zonal capillary electrophoresis (CZE) is a chromatographic separation methodology that, due to its high number of theoretical plates, speed, and relative ease-of-use, is increasingly replacing both GC-MS and high-pressure liquid chromatography as an analytical method for the quantification (particularly for quality control purposes) of anions, cations, amino acids, carbohydrates, and short chain carboxylic acids (SCCAs)8,9,10. CZE-based separation of small molecules, including SCCAs, is based two primary principles: the electrophoretic movement of charged ions in an electrical field established across the buffer filling the capillary; and the electro-osmotic movement of the entire buffer system from one end of the capillary to the other, generally towards the negative electrode. In this system, small molecules move towards the negative electrode at varying speeds, with the speed of each molecule determined by the ratio of the net charge of the molecule to the molecular mass. As the movement of each individual molecule in this system is dependent on the charge state of the molecule and the overall rate of electro-osmotic flow (which is itself based on the ion content of the buffer used to fill the capillary), the buffer pH and ionic composition heavily impact the degree to which molecules can be efficiently separated using CZE. Because of this, SCCAs, with their relatively high charge-to-mass ratios, are ideal targets for CZE-based separation. Metabolites separated using CZE can be detected using a variety of methods, including UV absorbance, spectral absorbance (which is generally performed using a photo-diode array [PDA]), and/or mass spectroscopy (CE-MS or CE-MS/MS)8. The diversity of separation and detection methods provided by CZE makes it an extremely flexible and adaptable technique. Because of this, CZE has been increasingly applied as a standard method of analysis in the areas of food safety and quality11,12, pharmaceutical research13, and environmental monitoring13,14. 
Capillary electrophoresis has been used to detect and quantify short chain carboxylic acids for nearly two decades13. The resolving power (particularly for small, charged molecules), short run time, and low per sample cost of CZE analyses make CZE an ideal technique for the separation and quantification of SCCAs13. This method presents a protocol to utilize CZE to measure the concentration of organic acids from plant tissues. Example data was generated through the successful implementation of this protocol to measure the change in organic acid levels in coffee seeds following a secondary fermentation treatment. The protocol details the critical steps and common errors of CZE-based separation of SCCAs, and discusses the means by which this protocol can be successfully applied to quantify SCCAs in additional plant tissues.

<table border="0" cellpadding="0" cellspacing="0" width="782">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="19">
			<td height="19" style="height:19px;width:296px;">Ceramic Moarter and Pestle</td>
			<td style="width:123px;">Coorstek</td>
			<td style="width:119px;">60310</td>
			<td style="width:247px;"></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:296px;">Beckman Coulter P/ACE MDQ CE system</td>
			<td style="width:123px;">Beckman Coulter</td>
			<td style="width:119px;">Various</td>
			<td style="width:247px;"></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:296px;">Glass sample vials</td>
			<td style="width:123px;">Fisher Inc.</td>
			<td style="width:119px;">033917D</td>
			<td style="width:247px;"></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:296px;">1.5 ml microcentrifuge tubes&#160;</td>
			<td style="width:123px;">Fisher Inc.</td>
			<td style="width:119px;">02-681-5</td>
			<td style="width:247px;"></td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:296px;">LC/MS grade water</td>
			<td style="width:123px;">Fisher Inc.</td>
			<td style="width:119px;">W6-1</td>
			<td style="width:247px;">Milli-Q water (18.2 M&#937;.cm) is also acceptable</td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:296px;">15 ml glass tube/ Teflon lined cap&#160;</td>
			<td style="width:123px;">Fisher Inc.</td>
			<td style="width:119px;">14-93331A</td>
			<td style="width:247px;"></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:296px;">Parafilm M</td>
			<td style="width:123px;">Fisher Inc.</td>
			<td style="width:119px;">13-374-12</td>
			<td style="width:247px;"></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:296px;">CElixirOA detection Kit pH 5.4&#160;</td>
			<td style="width:123px;">MicroSolv</td>
			<td style="width:119px;">06100-5.4</td>
			<td style="width:247px;"></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:296px;">BD Safety-Lok syringes</td>
			<td style="width:123px;">Fisher Inc.</td>
			<td style="width:119px;">14-829-32</td>
			<td style="width:247px;"></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:296px;">17 mm Target Syringe filter, PTFE</td>
			<td style="width:123px;">Fisher Inc.</td>
			<td style="width:119px;">3377154</td>
			<td style="width:247px;"></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:296px;">32 Karat, V. 8.0 control software</td>
			<td style="width:123px;">Beckman Coulter</td>
			<td style="width:119px;">285512</td>
			<td style="width:247px;"></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:296px;">capillary electrophoresis (CE) sample vials&#160;</td>
			<td style="width:123px;">Beckman Coulter</td>
			<td style="width:119px;">144980</td>
			<td style="width:247px;"></td>
		</tr>
		<tr height="19">
			<td height="19" style="height:19px;width:296px;">caps for CE vials&#160;</td>
			<td style="width:123px;">Beckman Coulter</td>
			<td style="width:119px;">144648</td>
			<td style="width:247px;"></td>
		</tr>
		<tr height="38">
			<td height="38" style="height:38px;width:296px;">Liquid Nitrogen</td>
			<td style="width:123px;">N/A</td>
			<td style="width:119px;">N/A</td>
			<td style="width:247px;">Liquid nitrogen is available from most facilities services</td>
		</tr>
	</tbody>
</table>

using capillary electrophoresis to quantify organic acids from plant tissue: a test case examining coffea arabica seeds

카르 복실 산, 하나 이상의 단말 카르복실기 (COOH) 작용기를 함유하는 유기산이다. 짧은 체인 카르 복실 산 (SCCAs, 3 ~ 6 탄소를 포함하는 카르 복실 산) 등의 말 산염과 구연산 등이, 그들은 세포 호흡에서 기능과 세포 건강의 지표 역할을 할 수있는 많은 생물 시스템의 적절한 기능에 중요하다. 식품에서의 유기산 함유량은 신 또는 &quot;산&quot;맛 결과 증가 SCCA 수준의 맛에 큰 영향을 가질 수있다. 이 때문에 유기산 농도의 신속한 분석을위한 방법은 음식 및 음료 산업에서 특히 중요하다. 그러나, 불행히도 SCCA 정량 방법에 사용 가장 비싼 크로마토 그래피 및 / 또는 질량 분광 분석을 하였다 위험한 시약과 시료의 유도체를 요구하는 시간 소모적 인 프로토콜에 의존한다. 이 방법은 조직의 검출과 정량을위한 다른 방법의 자세한 사항식물 재료 및 무료 띠 모세관 전기 영동 (CZE)를 이용하여 음식 샘플로부터 anic 산은 때때로 단순히 모세관 전기 영동 (CE) 라 함. CZE 검출의 하한 (0.005 ㎎ / ㎖)로 SCCAs을 측정하기위한 비용 효율적인 방법을 제공한다. 이 문서에서는 식물 샘플에서 SCCAs의 추출 및 정량을 자세히 설명합니다. 제공된 방법은 커피 콩 SCCAs 측정에 초점을 맞추고 있지만, 제공되는 방법은 여러 식물성 식품 재료에 적용될 수있다.

이 프로토콜은 성공적 녹색 커피 씨의 SCCA 내용에 시드 처리의 효과를 측정하기 위해 이용되고있다. 이 실험에서, 여섯 치료 하였다 : 로이코 노 스톡 포화 미생물 현탁액 물 GCP674 미생물 (1) 수성 현탁액 성장 배지에서 균주 GCP674을 pseudomesenteroides (2), 아세트산 및 락트산 (0.15 및 0.4의 수용액 밀리그램 /) 각각 ㎖ (3)와, 소요 M1 성장 배지 처리 (4), DH 2 O ?...

Watch this Scientific Journal Video about Using Capillary Electrophoresis to Quantify Organic Acids from Plant Tissue: A Test Case Examining Coffea arabica Seeds at JoVE.com

Using Capillary Electrophoresis to Quantify Organic Acids from Plant Tissue: A Test Case Examining Coffea arabica Seeds

이 문서에서는 검색 및 무료 띠 모세관 전기 영동을 이용하여 식물 재료에서 유기산 정량하는 방법을 제시한다. 커피 종자 유기산 농도에서 발효 차의 효과를 결정하는 이러한 방법의 잠재적 인 애플리케이션의 일례가 제공된다.

식물 조직에서 유기산을 정량화하는 모세관 전기 영동을 사용하여 : 테스트 케이스 검사<em&gt; 커피 나무 아라비카</em&gt; 씨앗

Carboxylic acids are organic acids containing one or more terminal carboxyl (COOH) functional groups. Short chain carboxylic acids (SCCAs; carboxylic ...

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Using Capillary Electrophoresis to Quantify Organic Acids from Plant Tissue: A Test Case Examining Coffea arabica Seeds

9.8K 조회수.  The Ohio State University, OARDC.  이 문서에서는 검색 및 무료 띠 모세관 전기 영동을 이용하여 식물 재료에서 유기산 정량하는 방법을 제시한다. 커피 종자 유기산 농도에서 발효 차의 효과를 결정하는 이러한 방법의 잠재적 인 애플리케이션의 일례가 제공된다. 

비디오: Using Capillary Electrophoresis to Quantify Organic Acids from Plant Tissue: A Test Case Examining Coffea arabica Seeds

Qualitative Identification of Carboxylic Acids, Boronic Acids, and Amines Using Cruciform Fluorophores

Molecular cruciforms are X-shaped systems in which two conjugation axes intersect at a central core. If one axis of these molecules is substituted with electron-donors, and the other with electron-acceptors, cruciforms&#39; HOMO will localize along the electron-rich and LUMO along the electron-poor axis. This spatial isolation of cruciforms&#39; frontier molecular orbitals (FMOs) is essential to their use as sensors, since analyte binding to the cruciform invariably changes its HOMO-LUMO gap and the associated optical properties. Using this principle, Bunz and Miljani&#263; groups developed 1,4-distyryl-2,5-bis(arylethynyl)benzene and benzobisoxazole cruciforms, respectively, which act as fluorescent sensors for metal ions, carboxylic acids, boronic acids, phenols, amines, and anions. The emission colors observed when these cruciform are mixed with analytes are highly sensitive to the details of analyte&#39;s structure and - because of cruciforms&#39; charge-separated excited states - to the solvent in which emission is observed. Structurally closely related species can be qualitatively distinguished within several analyte classes: (a) carboxylic acids; (b) boronic acids, and (c) metals. Using a hybrid sensing system composed from benzobisoxazole cruciforms and boronic acid additives, we were also able to discern among structurally similar: (d) small organic and inorganic anions, (e) amines, and (f) phenols. The method used for this qualitative distinction is exceedingly simple. Dilute solutions (typically 10-6 M) of cruciforms in several off-the-shelf solvents are placed in UV/Vis vials. Then, analytes of interest are added, either directly as solids or in concentrated solution. Fluorescence changes occur virtually instantaneously and can be recorded through standard digital photography using a semi-professional digital camera in a dark room. With minimal graphic manipulation, representative cut-outs of emission color photographs can be arranged into panels which permit quick naked-eye distinction among analytes. For quantification purposes, Red/Green/Blue values can be extracted from these photographs and the obtained numeric data can be statistically processed.

Cross-conjugated cruciform fluorophores based on 1,4-distyryl-2,5-bis(arylethynyl)benzene and benzobisoxazole nuclei can be used to qualitatively identify diverse Lewis acidic and Lewis basic analytes. This method relies on the differences in emission colors of the cruciforms that are observed upon analyte addition. Structurally closely related species can be distinguished from each other.

카르 복실 산, 붕소 산, 그리고 아민의 정성 식별 십자형 형광체를 사용하여

Molecular cruciforms are X-shaped systems in which two conjugation axes intersect at a central core. If one axis of these molecules is substituted with ...

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화학

Thin-layer Chromatographic (TLC) Separations and Bioassays of Plant Extracts to Identify Antimicrobial Compounds

A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the chromatograms to microbial suspensions (e.g. fungi or bacteria in broth or agar), allowing time for the microbes to grow in a humid environment, and visualizing zones with no microbial growth.&#160;The effectiveness of this screening method, known as bioautography, depends on both the quality of the chromatographic separation and the care taken with microbial culture conditions.&#160;This paper describes standard protocols for TLC and contact bioautography&#160;with a novel application to amino acid-fermenting bacteria. The extract is separated on flexible (aluminum-backed) silica TLC plates, and bands are visualized under ultraviolet (UV) light.&#160;Zones are cut out and incubated face down onto agar inoculated with the test microorganism.&#160;Inhibitory bands are visualized by staining the agar plates with tetrazolium red.&#160;The method is applied to the separation of red clover (Trifolium pratense cv. Kenland) phenolic compounds and their screening for activity against Clostridium sticklandii, a hyper ammonia-producing bacterium (HAB) that is native to the bovine rumen.&#160;The TLC methods apply to many types of plant extracts&#160;and other bacterial species (aerobic or anaerobic), as well as fungi, can be used as test organisms if culture conditions are modified to fit the growth requirements of the species.

Thin-layer Chromatographic TLC Separations and Bioassays of Plant Extracts to Identify Antimicrobial Compounds

Methods are described for thin-layer chromatographic (TLC) separation of plant extracts and contact bioautography to identify antibacterial metabolites. The methods are applied to the screening of red clover phenolic compounds inhibiting hyper&#160;ammonia-producing bacteria (HAB) native to the bovine rumen.

A common screen for plant antimicrobial compounds consists of separating plant extracts by paper or thin-layer chromatography (PC or TLC), exposing the ...

The Use of Gas Chromatography to Analyze Compositional Changes of Fatty Acids in Rat Liver Tissue during Pregnancy

Gas chromatography (GC) is a highly sensitive method used to identify and quantify the fatty acid content of lipids from tissues, cells, and plasma/serum, yielding results with high accuracy and high reproducibility. In metabolic and nutrition studies GC allows assessment of changes in fatty acid concentrations following interventions or during changes in physiological state such as pregnancy. Solid phase extraction (SPE) using aminopropyl silica cartridges allows separation of the major lipid classes including triacylglycerols, different phospholipids, and cholesteryl esters (CE). GC combined with SPE was used to analyze the changes in fatty acid composition of the CE fraction in the livers of virgin and pregnant rats that had been fed various high and low fat diets. There are significant diet/pregnancy interaction effects upon the omega-3 and omega-6 fatty acid content of liver CE, indicating that pregnant females have a different response to dietary manipulation than is seen among virgin females.

Pregnancy leads to significant changes to the fatty acid composition of maternal tissues. Lipid profiles can be obtained via gas chromatography to allow identification and quantification of fatty acids in individual lipid classes among rats fed various high and low fat diets during pregnancy.

임신 중 쥐의 간 조직에서 지방산의 작곡 변화를 분석하는 가스 크로마토 그래피의 사용

Gas chromatography (GC) is a highly sensitive method used to identify and quantify the fatty acid content of lipids from tissues, cells, and plasma/serum, ...

Analysis of Volatile and Oxidation Sensitive Compounds Using a Cold Inlet System and Electron Impact Mass Spectrometry

This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The analysis of volatile and oxidation sensitive compounds by mass spectrometry is not easily achieved, as all state-of-the-art mass spectrometric methods require at least one sample preparation step, e.g., dissolution and dilution of the analyte (electrospray ionization), co-crystallization of the analyte with a matrix compound (matrix-assisted laser desorption/ionization), or transfer of the prepared samples into the ionization source of the mass spectrometer, to be conducted under atmospheric conditions. Here, the use of a sample inlet system is described which enables the analysis of volatile metal organyls, silanes, and phosphanes using a sector field mass spectrometer equipped with an electron impact ionization source. All sample preparation steps and the sample introduction into the ion source of the mass spectrometer take place either under air-free conditions or under vacuum, enabling the analysis of compounds highly susceptible to oxidation. The presented technique is especially of interest for inorganic chemists, working with metal organyls, silanes, or phosphanes, which have to be handled using inert conditions, such as the Schlenk technique. The principle of operation is presented in this video.

This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The presented technique is especially of interest for inorganic chemists, working with metal organyls, silanes, or phosphanes which have to be handled using inert conditions, such as the Schlenk technique.

콜드 입구 시스템 및 전자 충격 질량 분석법을 사용하여 휘발성 및 산화에 민감한 화합물의 분석

This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The ...

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.

Synthesis, activation, and characterization of intentionally designed metal-organic framework materials is challenging, especially when building blocks are incompatible or unwanted polymorphs are thermodynamically favored over desired forms. We describe how applications of solvent-assisted linker exchange, powder X-ray diffraction in capillaries and activation via supercritical CO2 drying, can address some of these challenges.

기능화의 합성 및 특성 금속 - 유기 프레임 워크

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and ...

Capillary Electrophoresis to Monitor Peptide Grafting onto Chitosan Films in Real Time

Free-solution capillary electrophoresis (CE) separates analytes, generally charged compounds in solution through the application of an electric field. Compared to other analytical separation techniques, such as chromatography, CE is cheap, robust and effectively requires no sample preparation (for a number of complex natural matrices or polymeric samples). CE is fast and can be used to follow the evolution of mixtures in real time (e.g., chemical reaction kinetics), as the signals observed for the separated compounds are directly proportional to their quantity in solution.
Here, the efficiency of CE is demonstrated for monitoring the covalent grafting of peptides onto chitosan films for subsequent biomedical applications. Chitosan&#39;s antimicrobial and biocompatible properties make it an attractive material for biomedical applications such as cell growth substrates. Covalently grafting the peptide RGDS (arginine - glycine - aspartic acid - serine) onto the surface of chitosan films aims at improving cell attachment. Historically, chromatography and amino acid analysis have been used to provide a direct measurement of the amount of grafted peptide. However, the fast separation and absence of sample preparation provided by CE enables equally accurate yet real-time monitoring of the peptide grafting process. CE is able to separate and quantify the different components of the reaction mixture: the (non-grafted) peptide and the chemical coupling agents. In this way the use of CE results in improved films for downstream applications.
The chitosan films were characterized through solid-state NMR (nuclear magnetic resonance) spectroscopy. This technique is more time-consuming and cannot be applied in real time, but yields a direct measurement of the peptide and thus validates the CE technique.

Free solution capillary electrophoresis is a fast, cheap and robust analytical method that enables the quantitative monitoring of chemical reactions in real time. Its utility for rapid, convenient and precise analysis is demonstrated here through analysis of covalent peptide grafting onto chitosan films for improved cell adhesion.

모세관 전기 영동은 실시간으로 키토산 필름에 펩타이드 접목을 모니터링하는

Free-solution capillary electrophoresis (CE) separates analytes, generally charged compounds in solution through the application of an electric field. ...

Grafting Multiwalled Carbon Nanotubes with Polystyrene to Enable Self-Assembly and Anisotropic Patchiness

We demonstrate a straightforward protocol to graft pristine multiwalled carbon nanotubes (MWCNTs) with polystyrene (PS) chains at the sidewalls through a free-radical polymerization strategy to enable the modulation of the nanotube surface properties and produce supramolecular self-assembly of the nanostructures. First, a selective hydroxylation of the pristine nanotubes through a biphasic catalytically mediated oxidation reaction creates superficially distributed reactive sites at the sidewalls. The latter reactive sites are subsequently modified with methacrylic moieties using a silylated methacrylic precursor to create polymerizable sites. Those polymerizable groups can address further polymerization of styrene to produce a hybrid nanomaterial containing PS chains grafted to the nanotube sidewalls. The polymer-graft content, amount of silylated methacrylic moieties introduced and hydroxylation modification of the nanotubes are identified and quantified by Thermogravimetric Analysis (TGA). The presence of reactive functional groups hydroxyl and silylated methacrylate are confirmed by Fourier Transform Infrared Spectroscopy (FT-IR). Polystyrene-grafted carbon nanotube solutions in tetrahydrofuran (THF) provide wall-to-wall collinearly self-assembled nanotubes when cast samples are analyzed by transmission electron microscopy (TEM). Those self-assemblies are not obtained when suitable blanks are similarly cast from analogous solutions containing non-grafted counterparts. Therefore, this method enables the modification of the nanotube anisotropic patchiness at the sidewalls which results into spontaneous auto-organization at the nanoscale.

A procedure for the synthesis of polystyrene-grafted multiwalled carbon nanotubes using successive chemical modification steps to selectively introduce the polymer chains to the sidewalls and their self-assembly via anisotropic patchiness is presented.

자기 집합에 있도록 폴리스 티 렌과 이방성 Patchiness Multiwalled 탄소 나노튜브를 접목

We demonstrate a straightforward protocol to graft pristine multiwalled carbon nanotubes (MWCNTs) with polystyrene (PS) chains at the sidewalls through a ...

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds

Cyclic voltammetry (CV) is a technique used in the analysis of organic compounds. When this technique is combined with electron paramagnetic resonance (EPR) or ultraviolet-visible and near-infrared (UV-Vis-NIR) spectroscopies, we obtain useful information such as electron affinity, ionization potential, band-gap energies, the type of charge carriers, and degradation information that can be used to synthesize stable organic electronic devices. In this study, we present electrochemical and spectroelectrochemical methods to analyze the processes occurring in active layers of an organic device as well as the generated charge carriers.

In this article, we describe electrochemical, electron paramagnetic resonance, and ultraviolet-visible and near-infrared spectroelectrochemical methods to analyze organic compounds for application in organic electronics.

사용 하 여 순환 Voltammetry, UV-Vi-NIR, EPR Spectroelectrochemistry 유기 화합물 분석

Cyclic voltammetry (CV) is a technique used in the analysis of organic compounds. When this technique is combined with electron paramagnetic resonance ...

Microprobe Capillary Electrophoresis Mass Spectrometry for Single-cell Metabolomics in Live Frog (Xenopus laevis) Embryos

The quantification of small molecules in single cells raises new potentials for better understanding the basic processes that underlie embryonic development. To enable single-cell investigations directly in live embryos, new analytical approaches are needed, particularly those that are sensitive, selective, quantitative, robust, and scalable to different cell sizes. Here, we present a protocol that enables the in situ analysis of metabolism in single cells in freely developing embryos of the South African clawed frog (Xenopus laevis), a powerful model in cell and developmental biology. This approach uses a capillary microprobe to aspirate a defined portion from single identified cells in the embryo, leaving neighboring cells intact for subsequent analysis. The collected cell content is analyzed by a microscale capillary electrophoresis electrospray ionization (CE-ESI) interface coupled to a high-resolution tandem mass spectrometer. This approach is scalable to various cell sizes and compatible with the complex three-dimensional structure of the developing embryo. As an example, we demonstrate that microprobe single-cell CE-ESI-MS enables the elucidation of metabolic cell heterogeneity that unfolds as a progenitor cell gives rise to descendants during development of the embryo. Besides cell and developmental biology, the single-cell analysis protocols described here are amenable to other cell sizes, cell types, or animal models.

Microprobe Capillary Electrophoresis Mass Spectrometry for Single-cell Metabolomics in Live Frog Xenopus laevis Embryos

We describe steps that enable fast in situ sampling of a small portion of an individual cell with high precision and minimal invasion using capillary-based micro-sampling, to facilitate chemical characterization of a snapshot of metabolic activity in live embryos using a custom-built single cell capillary electrophoresis and mass spectrometry platform.

단일 셀 대사체학 라이브 개구리 (Xenopus laevis) 배아에 대 한 현미경 모 세관 전기 이동 법 질량 분석

The quantification of small molecules in single cells raises new potentials for better understanding the basic processes that underlie embryonic ...

Microfluidic Preparation of Liquid Crystalline Elastomer Actuators

This paper focuses on the microfluidic process (and its parameters) to prepare actuating particles from liquid crystalline elastomers. The preparation usually consists in the formation of droplets containing low molar mass liquid crystals at elevated temperatures. Subsequently, these particle precursors are oriented in the flow field of the capillary and solidified by a crosslinking polymerization, which produces the final actuating particles. The optimization of the process is necessary to obtain the actuating particles and the proper variation of the process parameters (temperature and flow rate) and allows variations of size and shape (from oblate to strongly prolate morphologies) as well as the magnitude of actuation. In addition, it is possible to vary the type of actuation from elongation to contraction depending on the director profile induced to the droplets during the flow in the capillary, which again depends on the microfluidic process and its parameters. Furthermore, particles of more complex shapes, like core-shell structures or Janus particles, can be prepared by adjusting the setup. By the variation of the chemical structure and the mode of crosslinking (solidification) of the liquid crystalline elastomer, it is also possible to prepare actuating particles triggered by heat or UV-vis irradiation.

This article describes the microfluidic process and parameters to prepare actuating particles from liquid crystalline elastomers. This process allows the preparation of actuating particles and the variation of their size and shape (from oblate to strongly prolate, core-shell, and Janus morphologies) as well as the magnitude of actuation.

액체 결정 탄성 액츄에이터의 미세 준비

This paper focuses on the microfluidic process (and its parameters) to prepare actuating particles from liquid crystalline elastomers. The preparation ...

식물 조직에서 유기산을 정량화하는 모세관 전기 영동을 사용하여 : 테스트 케이스 검사

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