1
|
Schena T, von Mühlen C. Chromatographic speed classification for liquid chromatography using average theoretical peak time (ATPT). Anal Chim Acta 2024; 1287:342092. [PMID: 38182344 DOI: 10.1016/j.aca.2023.342092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 11/19/2023] [Accepted: 11/29/2023] [Indexed: 01/07/2024]
Abstract
BACKGROUND The development of analytical techniques in the field of liquid chromatography has brought new frontiers in performance and analytical speed for the technique. The proper evaluation of the analytical boundaries achieved with those developments was not addressed in the literature, since different liquid chromatography (LC) techniques have not yet received any classification regarding their chromatographic speed. Defining chromatographic analysis speed based simply on analysis time is an outdated concept since it is sample and analyte-dependent. In this context, the application of the Average Theoretical Peak Time concept (ATPT) is proposed as a unified metric for chromatographic speed classification. RESULTS This metric was evaluated using PCA analysis in a group of more than 50 publications, which generated the classification of LC methods in normal, high, hyper, and ultra-high-speed separations using ATPT. Normal speed (ATPT values greater than 18000 ms/peak) was found in HPLC, nano-LC, SFC, and CEC methods. Therefore, high-speed methods (ATPT values between 4000 and 18000 ms/peak) were found in UHPLC techniques, while LC × LC methods presented higher ATPT values between 1000 and 4000 ms/peak being classified as hyper-speed separations. ATPT can also be used as an optimization parameter, since older methods show higher ATPT values, while recent published papers show lower values of this metric. This behavior is justified due to the improvement of the LC methods over the years. SIGNIFICANCE This work fulfills the gap in chromatographic definitions and metrics, regarding analytical speed in one-dimensional and multidimensional liquid chromatographic techniques and shows that ATPT metrics is a robust parameter that can be used to classify the separation speed as well as a metric to evaluate the LC Method optimization. It also corrects the historical application of separation time as a metric for chromatographic speed.
Collapse
Affiliation(s)
- Tiago Schena
- Faculty of Technology, Universidade Estadual do Rio de Janeiro (UERJ), Presidente Dutra highway, km 298, Resende, (RJ), 27537-000, Brazil; LECO Instruments, Av. Das Nações Unidas, 12399 - Cj121B, São Paulo, (SP), 04578-000, Brazil.
| | - Carin von Mühlen
- Faculty of Technology, Universidade Estadual do Rio de Janeiro (UERJ), Presidente Dutra highway, km 298, Resende, (RJ), 27537-000, Brazil.
| |
Collapse
|
2
|
Duarte RMBO, Brandão PF, Duarte AC. Multidimensional chromatography in environmental analysis: Comprehensive two-dimensional liquid versus gas chromatography. J Chromatogr A 2023; 1706:464288. [PMID: 37573757 DOI: 10.1016/j.chroma.2023.464288] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/22/2023] [Accepted: 08/07/2023] [Indexed: 08/15/2023]
Abstract
Analysis of complex environmental matrices poses an extreme challenge for analytical chemists due to the vast number of known and unknown compounds, with very diverse chemical and physical properties. The need for a holistic characterisation of this complexity has sparked the development of effective tools to unravel the chemical composition of such environmental samples. Multidimensional chromatographic methods, namely comprehensive two-dimensional (2D) gas and liquid chromatography (GC × GC and LC × LC, respectively), coupled to different detection systems have emerged as powerful tools with the capability to address this challenge. While GC × GC has steadily gained popularity in environmental analysis, LC × LC is surprisingly less attractive in this research field. This critical review article explores the potential reasons why LC × LC is not the dominant technique used in environmental analysis as compared to GC × GC, while simultaneously highlighting the quite unique role of LC × LC for the target and untargeted analysis of complex environmental matrices. The possible combinations of stationary phases, the important role of the interfacing valve as the heart of an LC × LC assembly, the existing optimization strategies for improving the separation power in the 2D chromatographic space, and the need for user-friendly mathematical tools for multidimensional data handling are also discussed. Finally, a set of practical measures are suggested to increase the use and secure the success of LC × LC in environmental analysis.
Collapse
Affiliation(s)
- Regina M B O Duarte
- Department of Chemistry, CESAM - Centre for Environmental and Marine Studies, University of Aveiro, Aveiro 3810-193, Portugal.
| | - Pedro F Brandão
- Department of Chemistry, CESAM - Centre for Environmental and Marine Studies, University of Aveiro, Aveiro 3810-193, Portugal
| | - Armando C Duarte
- Department of Chemistry, CESAM - Centre for Environmental and Marine Studies, University of Aveiro, Aveiro 3810-193, Portugal
| |
Collapse
|
3
|
Saint Germain FM, Faure K, Saunier E, Lerestif JM, Heinisch S. On-line 2D-RPLC x RPLC - HRMS to assess wastewater treatment in a pharmaceutical plant. J Pharm Biomed Anal 2022; 208:114465. [PMID: 34826673 DOI: 10.1016/j.jpba.2021.114465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/14/2021] [Accepted: 11/02/2021] [Indexed: 10/19/2022]
Abstract
Pharmaceutical effluents are complex media containing hundreds of compounds including active ingredients, intermediate products and unknown impurities. Bringing an industrial wastewater treatment plant (WWTP) into compliance with European directives requires a thorough analysis of the effluent. In this study, we demonstrate how online comprehensive two-dimensional liquid chromatography (on-line LC × LC) hyphenated to high resolution mass spectrometry (HRMS) can be a powerful analytical methodology to monitoring the outlet water, by analysing the content of known molecules while characterizing unknown compounds. Reversed phase liquid chromatography (RPLC) was used in both dimensions, with a penta-fluoro-phenyl silica-based column at neutral pH in the first dimension (1D) and a C18 column at acidic pH in the second one (2D). The conditions were optimized for a total analysis time of 60 min. The variability of both retention times and peak areas was evaluated. The average standard deviation on retention times was found to be less than 0.1 s in 2D. The relative standard deviation on peak area was about 7% for run-to-run analysis. This analytical approach, applied to the pharmaceutical effluents before (inlet) and after (outlet) wastewater treatment permitted to detect 240 compounds. These included 27 priority pharmaceutical products, 8 of which were of very high priority and their concentrations could be compared to target values. The comparison of 2D-LC and 1D-LC approaches clearly highlights the power of on-line RPLC x RPLC technique, which allows both targeted quantitative analysis and non-targeted qualitative analysis of pharmaceutical effluents.
Collapse
Affiliation(s)
- Fleur Marie Saint Germain
- ORIL Industrie, 13 rue Auguste Desgenetais, 76210 Bolbec, France; Université de Lyon, Institut des Sciences Analytiques, CNRS UMR 5280, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Karine Faure
- Université de Lyon, Institut des Sciences Analytiques, CNRS UMR 5280, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Estelle Saunier
- ORIL Industrie, 13 rue Auguste Desgenetais, 76210 Bolbec, France
| | | | - Sabine Heinisch
- Université de Lyon, Institut des Sciences Analytiques, CNRS UMR 5280, 5 rue de la Doua, 69100 Villeurbanne, France.
| |
Collapse
|
4
|
Multidimensional Analytical Characterization of Water-Soluble Organic Aerosols: Challenges and New Perspectives. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11062539] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Water-soluble organic aerosols (OA) are an important component of air particles and one of the key drivers that impact both climate and human health. Understanding the processes involving water-soluble OA depends on how well the chemical composition of this aerosol component is decoded. Yet, obtaining detailed information faces several challenges, including water-soluble OA collection, extraction, and chemical complexity. This review highlights the multidimensional non-targeted analytical strategies that have been developed and employed for providing new insights into the structural and molecular features of water-soluble organic components present in air particles. First, the most prominent high-resolution mass spectrometric methods for near real-time measurements of water-soluble OA and their limitations are discussed. Afterward, a special emphasis is given to the degree of compositional information provided by offline multidimensional analytical techniques, namely excitation–emission (EEM) fluorescence spectroscopy, high-resolution mass spectrometry and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and their hyphenation with chromatographic systems. The major challenges ahead on the application of these multidimensional analytical strategies for OA research are also addressed so that they can be used advantageously in future studies.
Collapse
|
5
|
Klyta J, Czaplicka M. Determination of secondary organic aerosol in particulate matter – Short review. Microchem J 2020. [DOI: 10.1016/j.microc.2020.104997] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
6
|
Kresse M, Drinda H, Romanotto A, Speer K. Simultaneous determination of pesticides, mycotoxins, and metabolites as well as other contaminants in cereals by LC-LC-MS/MS. J Chromatogr B Analyt Technol Biomed Life Sci 2019; 1117:86-102. [PMID: 31004850 DOI: 10.1016/j.jchromb.2019.04.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 03/28/2019] [Accepted: 04/04/2019] [Indexed: 10/27/2022]
Abstract
A 2D LC-MS/MS method for the simultaneous determination of 350 pesticides, 16 mycotoxins as well as the growth regulators Chlormequat and Mepiquat was developed. The method is applicable to cereals and products thereof. Attention should be paid to the simultaneous analysis of the cereal-relevant mycotoxins aflatoxin B1, B2, G1 and G2, ochratoxin A, deoxynivalenol and zearalenone. Moreover, the tropane alkaloids atropine/scopolamine could be integrated into the final method. The samples were extracted with a mixture of acetonitrile/water (80:20), diluted with acetonitrile and injected into an LC-LC-MS/MS system. There were no further manual clean-up steps. The automatic online clean-up took place during the HILIC-separation in the first dimension (YMC-Pack Diol; 2.1 × 100 mm; 5 μm, 120 Å). Here, polar matrix compounds were retained, while the majority of the analyte scope eluted in a fraction at the beginning of the analytical run. This fraction was transferred to the second dimension by a packed loop interface (Agilent Zorbax SB-C8; 4.6 × 12.5 mm; 5 μm; 80 Å). On the second column (Phenomenex Synergi Fusion RP C18; 2 × 100 mm; 2.5 μm; 100 Å), the majority of the scope was separated by a typical RP-gradient. Only some of the polar pesticides could not be transferred to the second column. They eluted directly after the transfer step from the HILIC-column to the MS/MS. The final method was sensitive enough to meet all the regulated maximum levels for pesticides in cereals according to EU Regulation 396/2005 and those for contaminants according to EU Regulation 1881/2006. Above all, the method was so robust and accurate that nearly 90% of the pesticides and all the tested mycotoxins, growth regulators and tropane alkaloids fulfilled the validation criteria of the SANTE guideline document, although the demanding criteria are only applicable to pesticides. For the verification, eight proficiency tests were passed successfully: three for the pesticide analysis, three for the mycotoxin analysis, and two for the analysis of the tropane alkaloids. In addition to the already mentioned contaminants, the six most important ergot alkaloids (e.g. ergotamine/ergotaminine) and two modified mycotoxins (deoxynivalenol-3-glucoside and zearalenone-sulfate, also known as masked mycotoxins) were detected during the routine analysis of rye and corn samples.
Collapse
Affiliation(s)
- Michael Kresse
- Landeslabor Berlin-Brandenburg, Rudower Chaussee 39, D-12489 Berlin, Germany.
| | - Heike Drinda
- Eurofins Sofia GmbH, Rudower Chaussee 29, D-12489 Berlin, Germany
| | - Anna Romanotto
- PICA Prüfinstitut Chemische Analytik, Rudower Chaussee 29, D-12489 Berlin, Germany
| | - Karl Speer
- Food Chemistry, Technical University Dresden, Bergstraße 66, D-01069 Dresden, Germany
| |
Collapse
|
7
|
Iguiniz M, Corbel E, Roques N, Heinisch S. Quantitative aspects in on-line comprehensive two-dimensional liquid chromatography for pharmaceutical applications. Talanta 2019; 195:272-280. [DOI: 10.1016/j.talanta.2018.11.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/07/2018] [Accepted: 11/09/2018] [Indexed: 02/03/2023]
|
8
|
Crenn V, Fronval I, Petitprez D, Riffault V. Fine particles sampled at an urban background site and an industrialized coastal site in Northern France - Part 1: Seasonal variations and chemical characterization. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 578:203-218. [PMID: 26685722 DOI: 10.1016/j.scitotenv.2015.11.165] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 11/27/2015] [Accepted: 11/29/2015] [Indexed: 06/05/2023]
Abstract
The chemical composition of particulate matter sampled at two French Northern sites (Douai, DO - urban background; Grande-Synthe, GS - industrialized coastal site) was investigated during two summer and winter field campaigns at each site. Measurements of the major chemical species (organic, sulfate, nitrate, ammonium, chloride) in the non-refractory submicron aerosols (NR-PM1) were carried out by a High Resolution Time-of-Flight Aerosol Mass Spectrometer. Black Carbon in PM2.5 was monitored using an Aethalometer, while the OC and EC fractions and some targeted chemical organic families (polycyclic aromatic hydrocarbons, PAHs; dicarboxylic acids, DCAs) were quantified by the simultaneous collection of PM2.5 on filters followed by offline analyses. The seasonal trends and winter-to-summer (W/S) concentration ratios are discussed in this paper. Results indicate that the total average mass concentrations of PM2.5 varied between 20.5μgm-3 and 32.6μgm-3 in DO and between 10.6μgm-3 and 29.9μgm-3 in GS during summer and winter, respectively. Similar concentration patterns were found for PAHs and Organic Carbon (OC, representing ~80% of the total carbon) with highest concentrations in winter at the urban site. DCA concentrations showed less seasonal variations, although the highest value also appeared during winter. Total NR-PM1 presented concentrations in summer lower by a factor of 4 (for DO) and 10 (for GS) than those observed in winter. Organics and nitrates dominated the NR-PM1 in DO for both seasons and during winter in GS while sulfates and nitrates were the most dominant species in summer in GS. Average chloride concentrations were slightly more important in GS than those in DO related to its use in industrial processes and no significant seasonal trend was observed. The size-resolved chemical composition showed that aerosols sampled in DO in winter are more aged than those collected in GS where fresh emissions of sulfate from the industrial sector were observed.
Collapse
Affiliation(s)
- V Crenn
- Département SAGE, Mines Douai, F-59508 Douai, France; Université de Lille, F-59000 Lille, France
| | - I Fronval
- Département SAGE, Mines Douai, F-59508 Douai, France; Université de Lille, F-59000 Lille, France
| | - D Petitprez
- PC2A, UMR CNRS-Lille1 8522, F-59655, Villeneuve d'Ascq, France; Université de Lille, F-59000 Lille, France
| | - V Riffault
- Département SAGE, Mines Douai, F-59508 Douai, France; Université de Lille, F-59000 Lille, France
| |
Collapse
|
9
|
Cao JL, Wei JC, Hu YJ, He CW, Chen MW, Wan JB, Li P. Qualitative and quantitative characterization of phenolic and diterpenoid constituents in Danshen (Salvia miltiorrhiza) by comprehensive two-dimensional liquid chromatography coupled with hybrid linear ion trap Orbitrap mass. J Chromatogr A 2016; 1427:79-89. [DOI: 10.1016/j.chroma.2015.11.078] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 11/20/2015] [Accepted: 11/25/2015] [Indexed: 01/06/2023]
|
10
|
Methods for characterization of organic compounds in atmospheric aerosol particles. Anal Bioanal Chem 2014; 407:5877-97. [DOI: 10.1007/s00216-014-8394-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 11/26/2014] [Accepted: 12/05/2014] [Indexed: 10/24/2022]
|
11
|
Place BJ, Morris MJ, Phillips MM, Sander LC, Rimmer CA. Evaluation of the impact of peak description on the quantitative capabilities of comprehensive two-dimensional liquid chromatography. J Chromatogr A 2014; 1368:107-15. [DOI: 10.1016/j.chroma.2014.09.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 07/22/2014] [Accepted: 09/24/2014] [Indexed: 10/24/2022]
|
12
|
Olariu RI, Vione D, Grinberg N, Arsene C. Applications of Liquid Chromatographic Techniques in the Chemical Characterization of Atmospheric Aerosols. J LIQ CHROMATOGR R T 2014. [DOI: 10.1080/10826076.2014.941256] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Romeo-Iulian Olariu
- a Department of Chemistry, Faculty of Chemistry, Laboratory of Analytical Chemistry , “Alexandru Ioan Cuza” University of Iasi , Iasi , Romania
| | - Davide Vione
- b Dipartimento di Chimica , Università di Torino , Torino , Italy
| | - Nelu Grinberg
- c Boehringer Ingelheim Pharmaceuticals Inc. , Ridgefield , Connecticut , USA
| | - Cecilia Arsene
- a Department of Chemistry, Faculty of Chemistry, Laboratory of Analytical Chemistry , “Alexandru Ioan Cuza” University of Iasi , Iasi , Romania
| |
Collapse
|
13
|
Reproducibility of retention time and peak area in comprehensive two-dimensional liquid chromatography. Anal Bioanal Chem 2014; 407:279-84. [DOI: 10.1007/s00216-014-8090-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 07/22/2014] [Accepted: 07/31/2014] [Indexed: 10/24/2022]
|
14
|
Ion chromatography-mass spectrometry: A review of recent technologies and applications in forensic and environmental explosives analysis. Anal Chim Acta 2014; 806:27-54. [DOI: 10.1016/j.aca.2013.10.047] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 10/21/2013] [Accepted: 10/27/2013] [Indexed: 11/18/2022]
|
15
|
Græsbøll R, Nielsen NJ, Christensen JH. Using the hydrophobic subtraction model to choose orthogonal columns for online comprehensive two-dimensional liquid chromatography. J Chromatogr A 2014; 1326:39-46. [DOI: 10.1016/j.chroma.2013.12.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 12/09/2013] [Accepted: 12/10/2013] [Indexed: 10/25/2022]
|
16
|
Trends in data processing of comprehensive two-dimensional chromatography: State of the art. J Chromatogr B Analyt Technol Biomed Life Sci 2012; 910:31-45. [DOI: 10.1016/j.jchromb.2012.06.039] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 06/04/2012] [Accepted: 06/29/2012] [Indexed: 12/20/2022]
|
17
|
Programmed elution in comprehensive two-dimensional liquid chromatography. J Chromatogr A 2012; 1255:112-29. [DOI: 10.1016/j.chroma.2012.02.071] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 02/23/2012] [Accepted: 02/24/2012] [Indexed: 11/23/2022]
|
18
|
Donato P, Cacciola F, Tranchida PQ, Dugo P, Mondello L. Mass spectrometry detection in comprehensive liquid chromatography: basic concepts, instrumental aspects, applications and trends. MASS SPECTROMETRY REVIEWS 2012; 31:523-559. [PMID: 22383300 DOI: 10.1002/mas.20353] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 11/10/2011] [Accepted: 11/10/2011] [Indexed: 05/31/2023]
Abstract
The review, as can be deduced from the title, focuses on both theoretical and practical aspects of the use of mass spectrometry as a third, added dimension to a comprehensive LC (LC × LC) system, generating the most powerful analytical tool today for non-volatile analytes. The first part deals with the technical requirements for linkage of an LC × LC system to an MS one, including the choice of the mobile phase (buffer and salts), flow rate (splitting), type of ionization (interface); advantages and disadvantages of off-line and on-line methods are discussed, as well. A discussion of the various aspects of instrumentation is provided, both from a chromatographic and mass spectrometry standpoint, with particular emphasis directed to the choice of column sets, spatial resolution, mass resolving power, mass accuracy, and tandem-MS capabilities. The extent to which mass spectrometry may be of aid in unraveling column-outlet multicompound bands is highlighted, along with its effectiveness as a chromatographic detector of excellent sensitivity, universality yet with potential in terms of selectivity and amenability to quantitative analysis over a wide dynamic range. The following section of the review contains significant applications of comprehensive two-dimensional LC coupled to MS in different areas of research, with details on interfaces, column stationary phases, modulation and MS parameters. It is not the intention of the authors to provide a comprehensive description of the techniques, but merely to discuss only those aspects which are essential for successful applications of the LC-MS combination. The reader will be acquainted with the enormous potential of this hyphenated technique, and the factors and instrumental developments that have concurred to make it emerge to a central role in specialized fields, such as proteomics.
Collapse
Affiliation(s)
- Paola Donato
- University Campus Bio-Medico, Via Álvaro del Portillo 21, 00128 Rome, Italy
| | | | | | | | | |
Collapse
|
19
|
Resolving the chemical heterogeneity of natural organic matter: new insights from comprehensive two-dimensional liquid chromatography. J Chromatogr A 2012; 1249:138-46. [PMID: 22738816 DOI: 10.1016/j.chroma.2012.06.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 05/09/2012] [Accepted: 06/10/2012] [Indexed: 11/21/2022]
Abstract
For the purpose of resolving the chemical heterogeneity of natural organic matter (NOM), comprehensive two-dimensional liquid chromatography (LC×LC) was employed for the first time to map the hydrophobicity versus molecular weight (MW) distribution of two well-known complex organic mixtures: Suwannee River Fulvic Acids (SR-FA) and Pony Lake Fulvic Acids (PL-FA). Two methods have been developed using either a conventional reversed-phase (RP) silica column or a mixed-mode hydrophilic interaction column operating under aqueous RP mode in the first dimension, and a size-exclusion column in the second dimension. The LC×LC fractions were screened on-line by UV at 254 nm, molecular fluorescence at excitation/emission wavelengths (λ(Exc)/λ(Em)) of 240/450 nm, and by evaporative light scattering. The MW distributions of these two NOM samples were further characterized by number (Mn) and weight (Mw) average MW, and by polydispersity (Mw/Mn). Findings suggest that the combination of two independent separation mechanisms is promising in extend the range of NOM separation. For the cases where NOM separation was accomplished, smaller Mw group fractions seem to be related to a more hydrophobic nature. Regardless of the detection method, the complete range of MW distribution provided by both comprehensive LC×LC methods was found to be lower than those reported in the literature.
Collapse
|
20
|
Carr P, Davis J, Rutan S, Stoll D. Principles of Online Comprehensive Multidimensional Liquid Chromatography. ADVANCES IN CHROMATOGRAPHY 2012; 50:139-235. [DOI: 10.1201/b11636-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
21
|
Pratt KA, Prather KA. Mass spectrometry of atmospheric aerosols--recent developments and applications. Part I: Off-line mass spectrometry techniques. MASS SPECTROMETRY REVIEWS 2012; 31:1-16. [PMID: 21442634 DOI: 10.1002/mas.20322] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 08/19/2010] [Accepted: 08/19/2010] [Indexed: 05/30/2023]
Abstract
Many of the significant advances in our understanding of atmospheric particles can be attributed to the application of mass spectrometry. Mass spectrometry provides high sensitivity with a fast response time to probe chemically complex particles. This review focuses on recent developments and applications in the field of mass spectrometry of atmospheric aerosols. In Part I of this two-part review, we concentrate on off-line mass spectrometry techniques, which require sample collection on filters but can provide detailed molecular speciation. In particular, off-line mass spectrometry techniques utilizing tandem mass spectrometry experiments and high resolution mass analyzers provide improved insight into secondary organic aerosol formation and heterogeneous reaction pathways through detailed structural elucidation at the molecular level.
Collapse
Affiliation(s)
- Kerri A Pratt
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | | |
Collapse
|
22
|
Wu ZY, Marriott PJ. One- and comprehensive two-dimensional high-performance liquid chromatography analysis of alkylphenol polyethoxylates. J Sep Sci 2011; 34:3322-9. [DOI: 10.1002/jssc.201100701] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 09/14/2011] [Accepted: 09/16/2011] [Indexed: 11/11/2022]
|
23
|
Bailey HP, Rutan SC, Carr PW. Factors that affect quantification of diode array data in comprehensive two-dimensional liquid chromatography using chemometric data analysis. J Chromatogr A 2011; 1218:8411-22. [DOI: 10.1016/j.chroma.2011.09.057] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 09/07/2011] [Accepted: 09/21/2011] [Indexed: 01/25/2023]
|
24
|
Duarte RM, Duarte AC. A critical review of advanced analytical techniques for water-soluble organic matter from atmospheric aerosols. Trends Analyt Chem 2011. [DOI: 10.1016/j.trac.2011.04.020] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
25
|
Kitanovski Z, Grgić I, Veber M. Characterization of carboxylic acids in atmospheric aerosols using hydrophilic interaction liquid chromatography tandem mass spectrometry. J Chromatogr A 2011; 1218:4417-25. [DOI: 10.1016/j.chroma.2011.05.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 02/28/2011] [Accepted: 05/09/2011] [Indexed: 10/18/2022]
|
26
|
Bailey HP, Rutan SC. Chemometric Resolution and Quantification of Four-Way Data Arising from Comprehensive 2D-LC-DAD Analysis of Human Urine. CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS : AN INTERNATIONAL JOURNAL SPONSORED BY THE CHEMOMETRICS SOCIETY 2011; 106:131-141. [PMID: 24013363 PMCID: PMC3762254 DOI: 10.1016/j.chemolab.2010.07.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Two-dimensional liquid chromatography (LC×LC) is quickly becoming an important technique for the analysis of complex samples, owing largely to the relatively high peak capacities attainable by this analytical technique. With the increase in the complexity of the sample comes a corresponding increase in the complexity of the collected data. Thus the need for chemometric methods capable of resolving and quantifying such data is ever more urgent in order to obtain the maximum information available from the data. To this end, we have developed a chemometric method that combines iterative key set factor analysis and multivariate curve resolution-alternating least squares analysis with a spectral selectivity constraint that is shown to be capable of resolving chromatographically rank deficient, non-multilinear data. (Spectrally rank deficient compounds can only be quantified if the peaks having the same spectra are chromatographically resolved.) Over 50 chromatographic peaks were found in a relatively small section of a LC×LC-diode array data set of replicate urine samples (a four-way data set) using the developed method. The relative concentrations for 34 of the 50 peaks were determined with % RSD values ranging from 0.09 % to 16 %.
Collapse
Affiliation(s)
| | - Sarah C. Rutan
- Corresponding author: Phone: 1-804-828-7517; FAX: 1-804-828-8599;
| |
Collapse
|
27
|
Effects of first dimension eluent composition in two-dimensional liquid chromatography. J Chromatogr A 2011; 1218:2214-21. [PMID: 21411103 DOI: 10.1016/j.chroma.2011.02.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 01/31/2011] [Accepted: 02/09/2011] [Indexed: 12/25/2022]
Abstract
Comprehensive two-dimensional liquid chromatography (LC×LC) has received a great deal of attention during the past few years because of its extraordinary resolving power. The biggest advantage of this technique is that very high peak capacities can be generated in a relatively short time. Numerous approaches to maximize the peak capacity in LC×LC have been employed. In this work we investigate the impact of the first dimension mobile phase on selectivity. LC×LC has several potential advantages over one-dimensional LC (1DLC) in that unconventional solvents, at least in reversed-phase LC, can be used. For example, solvents which strongly adsorb in the UV in the first dimension are not problematic in LC×LC. This so because the UV detector is placed after the second dimensional column, as pulses of the first dimension eluent arrive at the second dimensional column, they elute well before the solutes of interest and therefore do not interfere at all with detection of solute peaks. So far, the most widely used solvents in reversed-phase 1DLC are methanol and acetonitrile. However, the "UV advantage" of 2DLC allows us to employ UV active solvents, such as acetone. We compare their differential selectivities to that of acetonitrile for the separation of 23 indole acetic acids of interest in plant biology. We also apply them to the separation of a maize seed extract, a very complex sample. In both sample sets, mobile phase composition can be an important parameter to increase the orthogonality of the two dimensions and thus, to increase the effective peak capacity of LC×LC.
Collapse
|
28
|
Česla P, Fischer J, Jandera P. Separation of phenolic acids and flavone natural antioxidants by two-dimensional method combining liquid chromatography and micellar electrokinetic capillary chromatography. Electrophoresis 2010; 31:2200-10. [DOI: 10.1002/elps.200900689] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
29
|
Thekkudan DF, Rutan SC, Carr PW. A study of the precision and accuracy of peak quantification in comprehensive two-dimensional liquid chromatography in time. J Chromatogr A 2010; 1217:4313-27. [PMID: 20462587 PMCID: PMC2914511 DOI: 10.1016/j.chroma.2010.04.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Revised: 04/09/2010] [Accepted: 04/16/2010] [Indexed: 12/17/2022]
Abstract
Simulated chromatographic data were used to determine the precision and accuracy in the estimation of peak volumes (i.e., peak sizes) in comprehensive two-dimensional liquid chromatography in time (LCxLC). Peak volumes were determined both by summing the areas in the second dimension chromatograms and by fitting the second dimension areas to a Gaussian peak. The Gaussian method is better at predicting the peak volume than the moments method provided there are at least three second dimension injections above the limit of detection (LOD). However, when only two of the second dimension signals are substantially above baseline, the accuracy and precision of the Gaussian fit method become quite poor because the results from the fitting algorithm become indeterminate. Based on simulations in which the modulation ratio (M(R)=4(1)sigma/t(s)) and sampling phase (phi) were varied, we conclude for well-resolved peaks that the optimum precision in peak volumes in 2D separations will be obtained when the M(R) is between two and five, such that there are typically four to ten second dimension peaks recorded over the eight sigma width of the first dimension peak. This sampling rate is similar to that suggested by the Murphy-Schure-Foley criterion. This provides an RSD of approximately 2% for the signal-to-noise ratio used in the present simulations. The precision of the peak volume of experimental data was also assessed, and RSD values were in the range of 4-5%. We conclude that the poorer precision found in the LCxLC experimental data as compared to LC may be due to experimental imprecision in sampling the effluent from the first dimension column.
Collapse
Affiliation(s)
- Dennis F Thekkudan
- Department of Chemistry, Virginia Commonwealth University, Richmond, VA 23284-2006, USA
| | | | | |
Collapse
|
30
|
Dugo P, Kumm T, Cacciola F, Dugo G, Mondello L. Multidimensional Liquid Chromatographic Separations Applied to the Analysis of Food Samples. J LIQ CHROMATOGR R T 2010. [DOI: 10.1080/10826070802128888] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- P. Dugo
- a Dipartimento di Scienze degli Alimenti e dell'Ambiente, Facoltà di Scienze MM.FF.NN. , Università di Messina , Salita Sperone, 98166, Messina, Italy
| | - T. Kumm
- b Dipartimento Farmaco-chimico, Facoltà di Farmacia , Università di Messina , Messina, Italy
| | - F. Cacciola
- b Dipartimento Farmaco-chimico, Facoltà di Farmacia , Università di Messina , Messina, Italy
| | - G. Dugo
- b Dipartimento Farmaco-chimico, Facoltà di Farmacia , Università di Messina , Messina, Italy
| | - L. Mondello
- b Dipartimento Farmaco-chimico, Facoltà di Farmacia , Università di Messina , Messina, Italy
| |
Collapse
|
31
|
Jandera P, Hájek T, Česla P. Comparison of various second‐dimension gradient types in comprehensive two‐dimensional liquid chromatography. J Sep Sci 2010; 33:1382-97. [DOI: 10.1002/jssc.200900808] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Pavel Jandera
- Department of Analytical Chemistry, University of Pardubice, Pardubice, Czech Republic
| | - Tomáš Hájek
- Department of Analytical Chemistry, University of Pardubice, Pardubice, Czech Republic
| | - Petr Česla
- Department of Analytical Chemistry, University of Pardubice, Pardubice, Czech Republic
| |
Collapse
|
32
|
Comprehensive two-dimensional liquid chromatography to quantify polyphenols in red wines. J Chromatogr A 2009; 1216:7483-7. [DOI: 10.1016/j.chroma.2009.04.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 03/26/2009] [Accepted: 04/01/2009] [Indexed: 11/23/2022]
|
33
|
Development and validation of an ultra-high-performance liquid chromatography coupled to time-of-flight mass spectrometry method to quantify benzoic acid and long-chain monocarboxylic acids (C12–C28) in atmospheric aerosols. J Chromatogr A 2009; 1216:6481-9. [DOI: 10.1016/j.chroma.2009.07.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 07/21/2009] [Accepted: 07/22/2009] [Indexed: 11/21/2022]
|
34
|
Comprehensive liquid chromatography: Fundamental aspects and practical considerations—A review. Anal Chim Acta 2009; 641:14-31. [DOI: 10.1016/j.aca.2009.03.041] [Citation(s) in RCA: 169] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 03/23/2009] [Accepted: 03/24/2009] [Indexed: 10/21/2022]
|
35
|
Kallio M, Kivilompolo M, Varjo S, Jussila M, Hyötyläinen T. Data analysis programs for comprehensive two-dimensional chromatography. J Chromatogr A 2009; 1216:2923-7. [DOI: 10.1016/j.chroma.2008.11.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Revised: 11/11/2008] [Accepted: 11/12/2008] [Indexed: 10/21/2022]
|
36
|
Mondello L, Herrero M, Kumm T, Dugo P, Cortes H, Dugo G. Quantification in comprehensive two-dimensional liquid chromatography. Anal Chem 2008; 80:5418-24. [PMID: 18517223 DOI: 10.1021/ac800484y] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although the use of comprehensive two-dimensional liquid chromatography (LCxLC) as a powerful separation technique is continuously increasing, its employment in quantification experiments is rather limited. The present research is focused on the quantification of a series of standards, as well as real-world sample compounds, by using dedicated laboratory-constructed LCxLC software, developed through a novel approach. Moreover, the difficulties encountered during software operation, in various elution conditions, are described and discussed. The results attained were compared with those observed in conventional LC, and no statistically significant differences were observed in the determination of aurapten in grapefruit oil. However, a loss in sensitivity was observed when using LCxLC (limit of detection = 0.10 ppm) compared to conventional LC (limit of detection = 0.05 ppm) as a consequence of the sample dilution in comprehensive two-dimensional liquid chromatography.
Collapse
Affiliation(s)
- Luigi Mondello
- Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università di Messina, Viale Annunziata, 98168, Messina, Italy.
| | | | | | | | | | | |
Collapse
|
37
|
Optimization of separation in two-dimensional high-performance liquid chromatography by adjusting phase system selectivity and using programmed elution techniques. J Chromatogr A 2008; 1189:207-20. [DOI: 10.1016/j.chroma.2007.11.053] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2007] [Revised: 11/09/2007] [Accepted: 11/19/2007] [Indexed: 11/27/2022]
|
38
|
Kivilompolo M, Obůrka V, Hyötyläinen T. Comprehensive two-dimensional liquid chromatography in the analysis of antioxidant phenolic compounds in wines and juices. Anal Bioanal Chem 2008; 391:373-80. [DOI: 10.1007/s00216-008-1997-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Revised: 01/28/2008] [Accepted: 02/19/2008] [Indexed: 11/29/2022]
|
39
|
Characterization of selected organic compound classes in secondary organic aerosol from biogenic VOCs by HPLC/MS n. Anal Bioanal Chem 2008; 391:171-82. [DOI: 10.1007/s00216-008-1964-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 02/05/2008] [Accepted: 02/08/2008] [Indexed: 11/27/2022]
|
40
|
Dugo P, Cacciola F, Kumm T, Dugo G, Mondello L. Comprehensive multidimensional liquid chromatography: Theory and applications. J Chromatogr A 2008; 1184:353-68. [PMID: 17655853 DOI: 10.1016/j.chroma.2007.06.074] [Citation(s) in RCA: 231] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Revised: 06/27/2007] [Accepted: 06/28/2007] [Indexed: 11/23/2022]
Abstract
Comprehensive two-dimensional (2D) liquid chromatographic (LC x LC) techniques can be considered innovative methods only recently developed and adopted in many configurations. The revolutionary aspect of comprehensive two-dimensional techniques, with respect to classical multidimensional (MD) chromatography, is that the entire sample is subjected to the 2D advantage. The major benefit is that the separation capacities of each dimension are multiplied, offering a high peak capacity to resolve samples of great complexity. The first part of the present review briefly describes the theoretical and practical aspects related to the development of a multidimensional comprehensive liquid chromatographic method. Applicational experiences in comprehensive liquid chromatography are then described, divided into four groups, according to the HPLC modes used in the two dimensions and to the nature of the samples analyzed.
Collapse
Affiliation(s)
- Paola Dugo
- Dipartimento di Scienza degli alimenti e dell'ambiente, Facoltà di Scienze, Università di Messina, Salita Sperone 31, 98166 Messina, Italy.
| | | | | | | | | |
Collapse
|
41
|
Comprehensive two-dimensional liquid chromatography coupled with mass spectrometry. Anal Bioanal Chem 2008; 391:21-31. [DOI: 10.1007/s00216-008-1879-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Accepted: 01/11/2008] [Indexed: 10/22/2022]
|
42
|
Biological fingerprinting analysis of the traditional Chinese prescription Longdan Xiegan Decoction by on/off-line comprehensive two-dimensional biochromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 860:185-94. [DOI: 10.1016/j.jchromb.2007.10.027] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Revised: 10/17/2007] [Accepted: 10/18/2007] [Indexed: 11/23/2022]
|
43
|
François I, de Villiers A, Tienpont B, David F, Sandra P. Comprehensive two-dimensional liquid chromatography applying two parallel columns in the second dimension. J Chromatogr A 2007; 1178:33-42. [PMID: 18054028 DOI: 10.1016/j.chroma.2007.11.032] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Revised: 11/05/2007] [Accepted: 11/12/2007] [Indexed: 11/25/2022]
Abstract
The design of a new interface for comprehensive two-dimensional liquid chromatography (LC x LC) is described. To the conventionally used LC x LC system with the loop-type interface consisting of a two-position/ten-port switching valve equipped with two loops, an extra two-position/ten-port switching valve, a detector, a pump and a second column placed in parallel with the column in the second dimension, are added. The features of the interface are that the separation space in the second dimension is significantly enlarged and that the number of fractions transferred from the first to the second dimension can be increased, reducing the risk to lose resolution of the primary dimension. The potential of the system in NPLC x 2RPLC is illustrated with the analysis of a standard mixture and a lemon oil extract. For the lemon oil analysis, the effective peak capacity was increased from 437 using a conventional interface to 1095 with the new interface. RPLC x 2RPLC in combination with reduced modulation times was applied to the analysis of steroids and to the detection of impurities at the 0.05% relative concentration level in a sulfonamide drug sample.
Collapse
Affiliation(s)
- Isabelle François
- Ghent University, Department of Organic Chemistry, Krijgslaan 281 (S4-bis), B-9000 Ghent, Belgium
| | | | | | | | | |
Collapse
|
44
|
Stoll DR, Li X, Wang X, Carr PW, Porter SEG, Rutan SC. Fast, comprehensive two-dimensional liquid chromatography. J Chromatogr A 2007; 1168:3-43; discussion 2. [PMID: 17888443 PMCID: PMC3205947 DOI: 10.1016/j.chroma.2007.08.054] [Citation(s) in RCA: 307] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2007] [Revised: 07/09/2007] [Accepted: 08/10/2007] [Indexed: 11/21/2022]
Abstract
The absolute need to improve the separating power of liquid chromatography, especially for multi-constituent biological samples, is becoming increasingly evident. In response, over the past few years, there has been a great deal of interest in the development of two-dimensional liquid chromatography (2DLC). Just as 1DLC is preferred to 1DGC based on its compatibility with biological materials we believe that ultimately 2DLC will be preferred to the much more highly developed 2DGC for such samples. The huge advantage of 2D chromatographic techniques over 1D methods is inherent in the tremendous potential increase in peak capacity (resolving power). This is especially true of comprehensive 2D chromatography wherein it is possible, under ideal conditions, to obtain a total peak capacity equal to the product of the peak capacities of the first and second dimension separations. However, the very long timescale (typically several hours to tens of hours) of comprehensive 2DLC is clearly its chief drawback. Recent advances in the use of higher temperatures to speed up isocratic and gradient elution liquid chromatography have been used to decrease the time needed to do the second dimension LC separation of 2DLC to about 20s for a full gradient elution run. Thus, fast, high temperature LC is becoming a very promising technique. Peak capacities of over 2000 and rates of peak capacity production of nearly 1 peak/s have been achieved. In consequence, many real samples showing more than 200 peaks with signal to noise ratios of better than 10:1 have been run in total times of under 30 min. This report is not intended to be a comprehensive review of 2DLC, but is deliberately focused on the issues involved in doing fast 2DLC by means of elevating the column temperature; however, many issues of broader applicability will be discussed.
Collapse
Affiliation(s)
- Dwight R. Stoll
- University of Minnesota, Department of Chemistry, Smith and Kolthoff Halls, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Xiaoping Li
- University of Minnesota, Department of Chemistry, Smith and Kolthoff Halls, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Xiaoli Wang
- University of Minnesota, Department of Chemistry, Smith and Kolthoff Halls, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Peter W. Carr
- University of Minnesota, Department of Chemistry, Smith and Kolthoff Halls, 207 Pleasant Street SE, Minneapolis, MN 55455, USA
| | - Sarah E. G. Porter
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284-2006, USA
| | - Sarah C. Rutan
- Department of Chemistry, Virginia Commonwealth University, 1001 West Main Street, Richmond, VA 23284-2006, USA
| |
Collapse
|
45
|
Current literature in mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2007; 42:689-700. [PMID: 17474104 DOI: 10.1002/jms.1074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
|
46
|
Pól J, Hohnová B, Hyötyläinen T. Characterisation of Stevia Rebaudiana by comprehensive two-dimensional liquid chromatography time-of-flight mass spectrometry. J Chromatogr A 2007; 1150:85-92. [PMID: 16996528 DOI: 10.1016/j.chroma.2006.09.008] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 08/28/2006] [Accepted: 09/04/2006] [Indexed: 11/26/2022]
Abstract
Comprehensive two-dimensional liquid chromatography (LC x LC) connected on-line to electrospray ionisation time-of-flight mass spectrometry (ESI-TOF-MS) was employed for analysis of aqueous extract of Stevia rebaudiana. Different combinations of strong cation-exchange (SCX), amino (NH2), and octadecyl siloxane (C18) stationary phases were tested in the separation of all nine known sweet Stevia glycosides. A combination of C18 as the first-dimension column and NH2 as the second-dimension column fully separated all the glycosides from the matrix. The method proved to be quantitative and repeatable. The limit of detection (S/N=3) for stevioside, a widely used natural sweetener, was 43.4 ng/g in dry leaves. The RSD for retention times was <0.1% and that of peak areas 4.5%.
Collapse
Affiliation(s)
- Jaroslav Pól
- Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014, Finland
| | | | | |
Collapse
|
47
|
Williamson LN, Bartlett MG. Quantitative liquid chromatography/time-of-flight mass spectrometry. Biomed Chromatogr 2007; 21:567-76. [PMID: 17474074 DOI: 10.1002/bmc.844] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Over the last decade, time-of-flight (TOF) instruments have increasingly been used as quantitation tools. In addition, because of their high resolving power, they can be used for verification of empirical formulas. Historically, TOF instruments have had limited quantitation capabilities because of their narrow dynamic range. However, recent advances have improved these limitations. This review covers the rationale for using TOF for LC detection, and describes the many methods currently in the literature for the quantitation of pharmaceuticals, environmental pollutants, explosives and many phytochemicals.
Collapse
Affiliation(s)
- Leah N Williamson
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, The University of Georgia, Athens, GA 30602-2352, USA
| | | |
Collapse
|