Back to Journal

Annals of Chromatography and Separation Techniques

Current Status of Two-Dimensional Gel Electrophoresis and Multi-Dimensional Liquid Chromatography as Proteomic Separation Techniques

[ ISSN : 2473-0696 ]

Abstract Citation Editorial Acknowledgement References
Details

Received: 14-Oct-2015

Accepted: 15-Oct-2015

Published: 16-Oct-2015

Xianquan Zhan¹,²,³,⁴*

¹ Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, PR China
² Hunan Engineering Laboratory for Structural Biology and Drug Design, Xiangya Hospital, Central South University, PR China
³ State Local Joint Engineering Laboratory for Anticancer Drugs, Xiangya Hospital, Central South University, PR China
? The State Key Laboratory of Medical Genetics, Central South University, PR China

Corresponding Author:

Xianquan Zhan, Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Xiangya Hospital, Central South University, PR China, Tel: +86 731-84327905; Fax: +86-731-84327905; Email: yjzhan2011@gmail.com

Abstract

Proteomics is very important component in the era of post-genomics because it can address functions of genes and some important non-gene-determined biological issues such as Post Translational Modifications (PTMs), splicing, translocation, and spatial structure. Proteome is very complex, including multiple parameters such as kind of proteins, copy number of each protein, PTMs, isoforms, spatial structure of each protein, protein-protein interaction, and protein-other molecule interaction, etc. Moreover, proteome is dynamic, and alters with different conditions such as different physiological processes, different pathological processes, and different disease status.

Citation

Zhan X. Current Status of Two-Dimensional Gel Electrophoresis and Multi-Dimensional Liquid Chromatography as Proteomic Separation Techniques. Ann Chromatogr Sep Tech. 2015;1(2):1009.

Editorial

Proteomics is very important component in the era of post-genomics because it can address functions of genes and some important non-gene-determined biological issues such as Post Translational Modifications (PTMs), splicing, translocation, and spatial structure. Proteome is very complex, including multiple parameters such as kind of proteins, copy number of each protein,PTMs,isoforms,spatial structure of each protein, protein-protein interaction, and protein-other molecule interaction, etc. Moreover, proteome is dynamic, and alters with different conditions such as different physiological processes, different pathological processes, and different disease status, etc [1-3].Measurement of proteomic alteration would lead to discovery of important protein biomarkers for a given condition.Also, protein abundance alters in a huge range among different proteins within a proteome. Proteomic separation, identification, and bioinformatics are basic techniques in the field of proteomics.The protein species in a proteome must be separated prior to identification.The common proteomic separation techniques include Two-Dimensional Gel Electrophoresis (2DGE) [4,5] and Multi-Dimensional Liquid Chromatography (MDLC) [6,7].However, 2DGE and MDLC have their own advantages and disadvantages, and cannot be replaced with each other.

2DGE separates proteins based on two basic features of proteins – Isoelectric Point (pI) in the direction of Isoelectric Focusing (IEF) and Molecular Weight (Mw) in the direction of Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) [4]. 2DGE is an extensively used separation technique in the field of proteomics since the terms “proteome” and “proteomics” were proposed in 1994 [8]. Four main contributions of 2DGE in the field of proteomics are (1) 2DGE-based reference map of a proteome to expand proteome database [9,10],(2) 2DGE-based comparative proteomics to identify Differentially Expressed Proteins (DEPs) between a given condition and controls [11,12],(3) 2DGE-based Western blot coupled with a specific antibody to visually detect a kind of PTM in a proteome [13-15],and relatively quantify PTM-differential proteins between a given condition and controls [16,17], and (4) 2DGE-based Western blot coupled with a specific protein antibody to visually detect isoforms of that given protein in a proteome [18,19]. World-2DPAGE Constellation (http://world-2dpage.expasy.org) collected many 2DPAGE resources [20],including SWISS-2DPAGE (http://world-2dpage.expasy.org/swiss-2dpage),World 2DPAGE Repository (http://world-2dpage.expasy.org/repository),World-2DPAGE Portal (http:// world-2dpage.expasy.org/portal), and World-2DPAGE List (http://world-2dpage.expasy.org/ list). Of them,World-2DPAGE list contains references to known 2DPAGE database servers and 2DPAGE related servers and services, currently up to 60 databases and nearly 400 gel images, which is the most complete 2DPAGE list. World-2DPAGE portal is a dynamic and virtual portal, which integrates over 250 maps for 23 species; totally including nearly 40,000 identified spots, and is the biggest gel-based proteomics dataset available from a single interface.Two- dimensional difference in-gel electrophoresis (2D DIGE) is an improved 2DGE method, which uses flouresence dyes to label protein samples, and then equally mixes the labelled protein samples for 2DGE. 2D DIGE significantly lets spot-matching much easier, protein quantification more accurate and uses less amount of protein sample, compared to the classic 2 DGE.However, 2DGE and 2D DIGE are very labor-intensive, time-consuming, and low-throughput.It is difficult to distinguish the co-migration and overlapping of proteins with similar pI and Mr values which results in multiple proteins in one single spot [15], to well-separate the extremely acid/basic proteins and extremely high/low-mass proteins, and to detect low abundance proteins [1] although besides wide-range gradient IPG strip such as pH 3-10, a series of medium- and narrow-range of IPG strips, for example, pH 3-7, pH 4-7, pH 6-9, pH 6-11, pH 3.5-4.5, pH 4-5, pH 4.5-5.5, pH 5-6, and pH 5.5-6.7 IPG strips are developed to improve separation capability in a limited range of proteins [5,21].Therefore, 2DGE and 2D DIGE are limited in maximizing the coverage of a proteome relative to MDLC. However, 2DGE has its own advantages in visualization of protein component of a proteome, detection of protein isoforms or variants that are mainly derived from splicing and PTMs [13-17,22]. Protein isoforms or variants are very important issue because different isoforms or variants of a given protein are associated with a given condition such as a corresponding pathophysiological status, which play important roles in multiple biological processes [23,24].

MDLC coupled with tandem mass spectrometry (MDLC-MS/ MS) technique is superior to 2DGE in maximizing the coverage of a proteome and detecting low-abundance proteins [6,7]. The basic procedure of that strategy includes enzymatic peptides from a complex proteome, followed by separation in the first-dimension with any one of several different chromatography’s,and in the second-dimension with reversed-phase chromatography; the separated enzymatic peptides are on-line input into mass spectrometer for MS/MS analysis,followed by protein identification with database search. MDLC-MS/ MS-based proteomics techniques were developed rapidly, mainly including stable isotope-labeled MDLC-MS/MS [25] such as ICAT (Isotope-Coded Affinity Tags) [26-29], 18O [30,31], ICPL (Isotope Coded Protein Labeling) [32,33], IPTL (Isobaric Peptide Termini Labeling) [34,35], iTRAQ (Isobaric Tags For Relative And Absolute Quantification) [36,37], TMT (peptide Tandem Mass Tag) [38,39], and SILAC (Stable Isotope Labeling Of Amino Acids In Cell Culture) [40,41], and non-labeled MDLC-MS/MS such as label-free [42,43], SRM/MRM (Selected or Multiple Reaction Monitoring) [44,45],SWATH (Sequential Window Acquisition Of All Theoretical Spectra) [46,47], and AQUA (Absolute Quantification) [25,48], according to whether the sample is isotope-labeled or not.Those MDLC-MS/MS techniques have extensively used in the field of proteomics because of their high-throughput,high-accuracy, and high-sensitivity in analysis of a proteome, and that they easily overcome the disadvantages of 2DGE and 2D DIGE. However,MDLC is extensively used to separate the enzymatic peptide mixture, whereas 2DGE is extensively used to separate and visualize the intact protein mixture.MDLC is limited in identification of isoforms or variants of a given protein.

In summary, 2DGE is limited in maximizing proteome coverage but has its advantage in analysis protein isoforms or variants that are mainly derived from splicing and different PTMs. MDLC has its significant advantage in maximizing proteome coverage but is limited in analysis of intact protein isoforms or variants.Therefore, 2DGE and MDLC are complementary proteomic separation techniques with their own advantages and disadvantages in analysis of a proteome.

Acknowledgement

This work was supported by the grants from China “863” Plan Project (Grant No.2014AA020610-1 to X.Z.), Xiangya Hospital Funds for Talent Introduction (to X.Z.), the National Natural Science Foundation of China (Grant No. 81272798 and 81572278 to X.Z.), and Hunan Provincial Natural Science Foundation of China (Grant No. 14JJ7008 to X.Z.).

References

1. Zhan X, Desiderio DM. Comparative proteomics analysis of human pituitary adenomas: current status and future perspectives. Mass Spectrom Rev. 2005; 24: 783-813.

2. Anderson L, Seilhamer J. A comparison of selected mRNA and protein abundances in human liver. Electrophoresis. 1997; 18: 533-537.

3. Gygi SP, Rochon Y, Franza BR, Aebersold R. Correlation between protein and mRNA abundance in yeast.Mol Cell Biol. 1999; 19: 1720-1730.

4. O’Farrell PH. High resolution two-dimensional electrophoresis of proteins. J Biol Chem. 1975; 250: 4007-4021.

5. Görg A, Obermaier C, Boguth G, Harder A, Scheibe B. The current state of two-dimensional electrophoresis with immobilized pH gradients. Electrophoresis. 2000; 21: 1037-1053.

6. Wolters DA, Washburn MP, Yates JR. An automated multidimensional protein identification technology for shotgun proteomics. Anal Chem. 2001; 73: 5683-5690.

7. Aebersold R, Mann M. Mass spectrometry-based proteomics. Nature. 2003; 422: 198-207.

8. Wilkins MR, Sanchez JC, Gooley AA, Appel RD, Humphery-Smith I. Progress with proteome projects: why all proteins expressed by a genome should be identified and how to do it. Biotechnol Genet Eng Rev. 1996; 13: 19-50.

9. Zhan X, Desiderio DM. A reference map of a human pituitary adenoma proteome. Proteomics. 2003; 3: 699-713.

10. Wang X, Guo T, Peng F, Long Y, Mu Y, Yang H, et al. Proteomic and functional profiles of a follicle-stimulating hormone-positive human nonfunctional pituitary adenoma. Electrophoresis. 2015; 36: 1289-1304.

11. Moreno CS, Evans CO, Zhan X, Okor M, Desiderio DM. Novel molecular signaling and classification of human clinically nonfunctional pituitary adenomas identified by gene expression profiling and proteomic analyses. Cancer Res. 2005; 65: 10214-10222.

12. Evans CO, Moreno CS, Zhan X, McCabe MT, Vertino PM. Molecular pathogenesis of human prolactinomas identified by gene expression profiling, RT-qPCR, and proteomic analyses. Pituitary. 2008; 11: 231-245.

13. Zhan X, Desiderio DM. The human pituitary nitroproteome: detection of nitrotyrosyl-proteins with two-dimensional Western blotting, and amino acid sequence determination with mass spectrometry. Biochem Biophys Res Commun. 2004; 325: 1180-1186.

14. Zhan X, Desiderio DM. Linear ion-trap mass spectrometric characterization of human pituitary nitrotyrosine-containing proteins. Int J Mass Spectrum. 2007; 259: 96-104.

15. Peng F, Li J, Guo T, Yang H, Li M, Sang S, Li X, Desiderio M, Zhan X. Nitroproteins in human astrocytomas discovered by gel electrophoresis and tandem mass spectrometry. J Am Soc Mass Spectrum. 2015; DOI: 10.1007/ S13361-015-1270-3.

16. Miyagi M, Sakaguchi H, Darrow RM, Yan L, West KA. Evidence that light modulates protein nitration in rat retina. Mol Cell Proteomics. 2002; 1: 293 303.

17. Turko IV, Li L, Aulak KS, Stuehr DJ, Chang JY, Murad F. Protein tyrosine nitration in the mitochondria from diabetic mouse heart. Implications to dysfunctional mitochondria in diabetes. J Biol Chem. 2003; 278: 33972 33977.

18. Kohler M, Thomas A, Püschel K, Schänzer W, Thevis M. Identification of human pituitary growth hormone variants by mass spectrometry.J Proteome Res. 2009; 8: 1071-1076.

19. Prasannan L, Misek DE, Hinderer R, Michon J, Geiger JD. Identification of beta-tubulin isoforms as tumor antigens in neuroblastoma. Clin Cancer Res. 2000; 6: 3949-3956.

20. Hooglanda C, Mostaguira K, Appela RD, Lisaceka F. The World-2DPAGE Constellation to promote and publish gel-based proteomics data through the ExPASy server. J Proteomics. 2008; 71: 245-248.

21. Görg A, Postel W, Günther S. The current state of two-dimensional electrophoresis with immobilized pH gradients. Electrophoresis. 1988; 9: 531-546.

22. Zhan X, Giorgianni F, Desiderio DM. Proteomics analysis of growth hormone isoforms in the human pituitary.Proteomics. 2005; 5: 1228-1241.

23. Rogowska-Wrzesinska A, Le Bihan MC, Thaysen-Andersen M, Roepstorff P. 2D gels still has a niche in proteomics. J Proteomics. 2013; 88: 4-13.

24. Stastna M, Van Eyk JE. Analysis of protein isoforms: can we do it better? Proteomics. 2012; 12: 2937-2948.

25. Chahrour O, Cobice D, Malone J. Stable isotope labelling methods in mass spectrometry-based quantitative proteomics. J Pharm Biomed Anal. 2015; 113: 2-20.

26. Sethi S, Chourasia D, Parhar IS. Approaches for targeted proteomics and its potential applications in neuroscience. J Biosci. 2015; 40: 607-627.

27. Fan X, Zhou S, Wang B, Hom G, Guo M, Li B, et al. Evidence of highly conserved ß-crystallin disulfidome that can be mimicked by in vitro oxidation in age-related human cataract and glutathione depleted LEGSKO mouse lens. Mol Cell Proteomics. 2015.

28. Gygi SP, Rist B, Gerber SA, Turecek F, Gelb MH. Quantitative analysis of complex protein mixtures using isotope-coded affinity tags. Nat Biotechnol. 1999; 17: 994-999.

29. Shiio Y, Aebersold R. Quantitative proteome analysis using isotope-coded affinity tags and mass spectrometry. Nat Protoc. 2006; 1: 139-145.

30. Miyagi M, Rao KC. Proteolytic 18O-labeling strategies for quantitative proteomics. Mass Spectrum Rev. 2007; 26: 121-136.

31. Capelo JL, Carreira RJ, Fernandes L, Lodeiro C, Santos HM, Simal-Gandara J. Latest developments in sample treatment for 18O-isotopic labeling for proteomics mass spectrometry-based approaches: a critical review. Talanta. 2010; 80: 1476-1486.

32. Biniossek ML, Lechel A, Rudolph KL, Martens UM, Zimmermann S. Quantitative proteomic profiling of tumor cell response to telomere dysfunction using Isotope-Coded Protein Labeling (ICPL) reveals interaction network of candidate senescence markers. J Proteomics. 2013; 91: 515-535.

33. Brunner A, Kellermann J, Lottspeich F. A practical guide to the ICPL_ ESIQuant software for ICPL-based quantitative proteomics. Biochim Biophys Acta. 2014; 1844: 21-28.

34. Koehler CJ, Strozynski M, Kozielski F, Treumann A, Thiede B. Isobaric peptide termini labeling for MS/MS-based quantitative proteomics. J Proteome Res. 2009; 8: 4333-4341.

35. Arntzen MØ, Koehler CJ, Barsnes H, Berven FS, Treumann A. IsobariQ: software for isobaric quantitative proteomics using IPTL, iTRAQ, and TMT. J Proteome Res. 2011; 10: 913-920.

36. Evans C, Noirel J, Ow SY, Salim M, Pereira-Medrano AG. An insight into iTRAQ: where do we stand now? Anal Bioanal Chem. 2012; 404: 1011-1027.

37. Aggarwal K, Choe LH, Lee KH. Shotgun proteomics using the iTRAQ isobaric tags. Brief Funct Genomic Proteomic. 2006; 5: 112-120.

38. Rauniyar N, Yates JR. Isobaric labeling-based relative quantification in shotgun proteomics. J Proteome Res. 2014; 13: 5293-5309.

39. O’Brien DP, Timms JF. Employing TMT quantification in a shotgun-MS platform. Methods Mol Biol. 2014; 1156: 187-199.

40. Bell-Temin H, Culver-Cochran AE, Chaput D, Carlson CM, Kuehl MN. Novel molecular insights into classical and alternative activation states of microglia as revealed by SILAC-based proteomics. Mol Cell Proteomics. 2015.

41. Hoedt E, Zhang G, Neubert TA. Stable Isotope Labeling by Amino Acids in Cell Culture (SILAC) for quantitative proteomics. Adv Exp Med Biol. 2014; 806: 93-106.

42. Guo H, Isserlin R, Lugowski A, Kuzmanov U, Emili A. Large-scale label-free phosphoproteomics: from technology to data interpretation. Bioanalysis. 2014; 6: 2403-2420.

43. Matzke MM, Brown JN, Gritsenko MA, Metz TO, Pounds JG, Rodland KD, et al. A comparative analysis of computational approaches to relative protein quantification using peptide peak intensities in label-free LC-MS proteomics experiments. Proteomics. 2013; 13: 493-503.

44. Colangelo CM, Chung L, Bruce C, Cheung KH. Review of software tools for design and analysis of large scale MRM proteomic datasets. Methods. 2013; 61: 287-298.

45. Lemoine J, Fortin T, Salvador A, Jaffuel A, Charrier JP. The current status of clinical proteomics and the use of MRM and MRM (3) for biomarker validation. Expert Rev Mol Diagn. 2012; 12: 333-342.

46. Gillet LC, Navarro P, Tate S, Röst H, Selevsek N. Targeted data extraction of the MS/MS spectra generated by data-independent acquisition: a new concept for consistent and accurate proteome analysis. Mol Cell Proteomics. 2012; 11: O111.

47. Lambert JP, Ivosev G, Couzens AL, Larsen B, Taipale M, Lin ZY, et al. Mapping differential interactomes by affinity purification coupled with data independent mass spectrometry acquisition. Nat Methods. 2013; 10: 1239 1245.

48. Muntel J, Fromion V, Goelzer A, Maaß S, Mäder U, Büttner K, et al. Comprehensive absolute quantification of the cytosolic proteome of Bacillus subtilis by data independent, parallel fragmentation in liquid chromatography/ mass spectrometry (LC/MS (E)). Mol Cell Proteomics. 2014; 13: 1008-1019.

Other Articles

Article Image 1

Removal of Acid Beverage Flocs in Crystal Sugar by Adsorption Column Chromatography: Preliminary Study with Adsorbent Resin

The sugar industry has been facing some problems with white sugar intended for soft drinks production. Some studies have been demonstrated the sugar could be source of insoluble substances technically called by Acid Beverage Flocs (ABF). It appears during the beverage production; however, the flocs are easily disappearing with shaking. This may be related to raw material the sugarcane quality and, consequently, with the efficiency of the juice clarification process, since if there is no adequate juice treatment. The sugarcane commonly has lower quality and higher intensity of impurities, such as proteins, wax, minerals and colloids. The sugar industries are implementing solutions to reduce the amount of impurities through using technologies like ionic resins to removal of color, odor or undesirable taste. It could transform raw sugar in refined or white sugars. The aim of this work was evaluate the efficiency of purification of sugar solution with chromatographic adsorption system. We observed that the color reduction was around 69% and an intensive reduction in turbidity of sugar aqueous solution. There were variation on sucrose and increase on reducing sugars (glucose and fructose) contents. It is possible to conclude that the process could be efficient to reduce the color (MAU color), turbidity and ABF into sugar solutions.

Roberta Bergamin Lima and Claudio Lima de Aguiar*


Article Image 1

A Study to Evaluate Aflatoxin Contamination in Food from Gauteng Province

Aflatoxins (AFs) and their producers have been found to be problematic and is still an issue. This is due to their role in influencing food quality, health and economy loss. In maintaining good food quality, minimize AFs occurrence and its deleterious effects, it is essential that issues relating to mycotoxin production and contamination are monitored, and addressed on a regular basis. This will proffer suggestions for immediate actions to be taken, in order to achieve and maintain regulatory limit before situations are out of control. Hence the case study to evaluate the concentration of AFs in food, by way of thin layer chromatography and high performance liquid chromatography was attempted. This is to monitor concentrations of the emerging mycotoxin in relation to international regulatory limits. Concentrations levels ranging 0.06 - 77.97 ppb was observed, (mean: 16.8 ppb) and measured out in the food samples of study, exceeding the ISO limits (0.05 ppb). This calls for proper monitoring of pre and postproduction stages in food, by employing easy to use chromatographic techniques as a routine process to screen and ascertain concentrations do not exceed regulatory limits.

Henry E Iheanacho¹,²,³*


Article Image 1

Investigation of Naturally Occurring Fumonisin B1 and Glycated Fumonisin B1 in Korean Feedstuffs

Mycotoxins are potentially dangerous contaminants of livestock feeds. In this study, we measured the levels of fumonisin B1 and glycated fumonisin B1 in feedstuffs and then investigated the ability of the extrusion heating regimen to convert the most prevalent mycotoxin contaminant, fumonisin B1 , to a less toxic glycated form. All feed samples were analyzed with fully validated methods. All measured concentrations of fumonisin B1 were below harmful thresholds, including European Union-recommended levels or US Food and Drug Administration action levels.

Because fumonisin B1 was highly contaminated mycotoxin in our present investigation and fumonisin B1 has been shown to be less toxic following Maillard type reaction with reducing sugar, we examined the formation of fumonisin B1 derivatives by Maillard reaction under extrusion process conditions. We employed a variety of tandem mass spectrometric methodologies to selectively detect fumonisin B1 derivatives and to elucidate their structures partially. We found that compounds of m/z 736 were more likely artifacts or side reaction products rather than glycation products. N-(carboxymethyl) fumonisin B1 of m/z 780 and other major glycation products of m/z 794 and 810 were not detected, and only negligible amounts of methylene fumonisin B1 was found in 10 extruded feed samples. Therefore, either the tested extrusion conditions did not induce fumonisin B1 glycation or the glycation products simply could not be detected by the method employed in this study.

Jongsung Ahn¹, Hyenjong Kim¹, and Kwang-Yeop Jahng²*


Article Image 1

Determination of HMF in Some Instant Foods and Its Biodegradation by Some Lactic Acid Bacteria in Medium and Food

The aims of this study were to determine HMF level in some foods and to reduce their level by biodegradation. Coffee whitener, cappuccino, hot chocolate, instant coffee, instant powdered mix (coffee, coffee whitener and sugar) and aromatized cocoa were subjected to HMF analysis in the scope of this study. The HMF determination of samples was carried out using a high performance liquid chromatography. Color properties of the samples were determined according to standard procedures and their relations with HMF content were also investigated. The biological degradation of HMF with lactic acid bacteria was also studied with broth media and a model food system (reconstituted milk).The average HMF levels were 12.59 mg/kg for coffee whitener, 572.49 mg/ kg for cappuccino, 660.29 mg/kg for hot chocolate, 1804.91 mg/kg for instant coffee, 871.56 mg/kg for instant powdered mix and 980.94 mg/kg for aromatized cocoa. The addition of lactic acid cultures reduced the HMF content of the samples. HMF levels of broth media and model food inoculated with lactic acid bacteria (L. lactis, L.bulgaricus, L. cremoris) decreased about 25 % as a result of HMF biodegradation.

Rasim Alper Oral¹, Mahmut Dogan², Kemal Sarıoglu², Ahmed Kayacıer¹, and Osman Sagdic³*


Article Image 1

An Integrated Analysis of the Musa Paradisiaca Peel, Using UHPLC-ESI, FT IR and Confocal Microscopy Techniques

When the banana (Musa paradisiaca) peel was subject of enzymatic hydrolysis with cellulase and hemicellulase, only glucose was obtained. Images from banana peel, using confocal laser scanning microscopy, demonstrate that the cellulose is the main structural compound. Fatty acids, phenolic and other compounds were detected from the organic residual extract, and characterized by means of NMR, FT-IR and UHPLC-MS techniques. The presences of these compounds were corroborated through a steam distillation. Under this condition, banana peel could have potential applications in the food field, where could be used to improve some procedures such as the obtaining of banana vinegar.

Miriam Alejandra González Corona¹, Mayra Beatriz Gómez-Patiño², María de Jesús Perea Flores², Luis Alberto Moreno Ruiz², Blanca Margarita Berdeja Martinez¹, and Daniel Arrieta-Baez²*


Article Image 1

Structural Characterization of Bamboo Lignin Isolated With Formic Acid and Alkaline Peroxide by Gel Permeation Chromatography and Pyrolysis Gas Chromatography Mass Spectrometry

Fractionation is an effective technology to maximize the utilization of lignocelluloses for the production of chemicals and materials. In this case, bamboo was subjected to a two-step fractionation process based on the concept of biorefinery: (a) formic acid treatment at boiling point under atmospheric pressure for 2 h, and (b) post treatment with alkaline hydrogen peroxide solution containing 1% NaOH and 1% H2 O2 at 80 ºC. The combination of formic acid delignification and alkaline hydrogen peroxide degradation achieved an effective removal of both lignin (delignification rate 94.9%) and hemicelluloses (removal rate 87.4%) from bamboo, producing cellulose rich pulp, formic acid lignin and sugars. To investigate the structural modification of lignin during the fractionation process, the residual lignin in the treated samples was isolated and characterized with multiply techniques including gel permeation chromatography, pyrolysis gas chromatography mass spectrometry, Fourier-transform infrared spectroscopy, etc. The relative ratio of S/G was 1.63 for bamboo milled wood lignin (L1), whereas the lignin isolated from the formic acid treated cellulose-rich fraction (L2) presented a chromatograph similar to that of L1 but had a lower S/G ratio of 1.28. This indicated that a preferential removal of S units during the formic acid fractionation process. In addition, alkaline hydrogen peroxide treatment resulted in more removal of S units, as indicated by a lower S/G ratio of 0.71.

Xun Li¹, Chang-Zhou Chen¹, and Ming-Fei Li¹*

 


Article Image 1

Volatile Compound Profiles by HS GC MS for the Evaluation of Postharvest Conditions of a Peach Cultivar

Volatile Organic Compounds (VOCs) profile of foods obtained by Gas Chromatography/Mass Spectrometry (GC/MS) can be considered a potent tool of food products quality changes occurring as a result of different processing, such as ripening and deterioration. The aim of the present study was the evaluation of volatiles profiles of peaches (cv Springcrest) during their storage in conditions similar to those of long distance transport that normally these products undergo before being placed on market. We investigated control sample (no stored fruit) and peaches stored in cardboard boxes wrapped in heat-sealed HD polythene bags, both in normal and modified atmosphere (0% and 23% CO2 ) after 1 and 8 days of storage at 4°C. GC/MS analysis of these samples allowed the identification of a total of 115 VOCs.

The comparison of the VOCs profile of the three peach samples (control, normal atmosphere and 23% CO2 ) shows that fruits packaged in normal atmosphere released a greater amount of esters of medium chain fatty acids, such as ethyl nonanoate and ethyl dodecanoate. On the other hand, fruits stored in normal atmosphere and modified atmosphere after 8 days of storage (increased concentration of CO2 in packs) released a greater amount of esters of long chain fatty acids, such as ethyl hexadecanoate.

Livia Malorni¹, Antonella Martignetti¹, and Rosaria Cozzolino¹*


Article Image 1

Current Trends in Lignocellulosic Analysis with Chromatography

The conversion of lignocellulosic biomass into biofuel and biomaterial is promising for the substitution of fossil resources in energy and material applications. Given the complexity of plant cell wall, the main challenge is to obtain lignocelluloses with high yield and purity. For a better understanding of lignocellulosic biomass, chromatography stands out as a powerful separation method that can support the lab directed research and pilot scale production of biomaterial and biochemical. This paper provides a review on the characterization of cellulose, hemicellulose and lignin along with their derivatives and decomposed sugar monomers, in particular their isolation and purificationmethods using various specific types of chromatography. Methods with various specific types of chromatography. This review also summarizes different chromatographic methods for obtaining the molecular weights of cellulose, hemicellulose and lignin that have been used in recent years, and highlights future opportunities for the application of those biopolymers.

Fengbo Sun¹ and Qining Sun²*


Article Image 1

Validation of Assay Indicating Method Development of Imatinib in Bulk and Its Capsule Dosage Form by Liquid Chromatography

A novel, simple and economic reverse phase High Performance Liquid Chromatography (RP-HPLC) method has been developed for the quantification of Imatinib in bulk and capsule dosage form with greater precision and accuracy. Separation was achieved on Analytical technologies, C-18, (250mm*4.6mm) column in isocratic mode with mobile phase consisting of acetonitrile: potassium dihydrogen phosphate buffer (pH 2.5) (30:70v/v) with a f low rate of 0.8 mL/min. The detection was carried out at 268 nm. The retention time of Imatinib was found to be 2.67 min. The method was validated as per ICH guidelines. Linearity was established for Imatinib in the range 5-35 μg / ml with r2 value 0.996. The percentage recovery of Imatinib was found to be in the range 99.49-99.67 %. The high recovery and low relative standard deviation confirm the suitability of the proposed method for the estimation of the drug in bulk and capsule dosage forms. Validation studies demonstrated that the proposed RP-HPLC method is simple, specific, rapid, reliable and reproducible for the determination of Imatinib for quality control level.

Nalini Kanta Sahoo¹, Madhusmita Sahu¹, V Alagarsamy¹, B Srividya², and Chinmaya Keshari Sahoo³*

 

 

Article Image 1

Chromatography & Separations

I started off my career as a biotechnologist in the early eighties, of the last century, using mainly size exclusion chromatography to identify biologically active substances, from ovine broncho alveolar macrophages co-cultured with lymphocytes, from the lungs of young sheep infected with Jaagsiekte Retrovirus (JSRV)

MS Myer1*