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Adels K, Elbers G, Diehl B, Monakhova Y. Multicomponent analysis of dietary supplements containing glucosamine and chondroitin: comparative low- and high-field NMR spectroscopic study. ANAL SCI 2024; 40:101-113. [PMID: 37819571 PMCID: PMC10766784 DOI: 10.1007/s44211-023-00433-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 09/22/2023] [Indexed: 10/13/2023]
Abstract
With the prevalence of glucosamine- and chondroitin-containing dietary supplements for people with osteoarthritis in the marketplace, it is important to have an accurate and reproducible analytical method for the quantitation of these compounds in finished products. NMR spectroscopic method based both on low- (80 MHz) and high- (500-600 MHz) field NMR instrumentation was established, compared and validated for the determination of chondroitin sulfate and glucosamine in dietary supplements. The proposed method was applied for analysis of 20 different dietary supplements. In the majority of cases, quantification results obtained on the low-field NMR spectrometer are similar to those obtained with high-field 500-600 MHz NMR devices. Validation results in terms of accuracy, precision, reproducibility, limit of detection and recovery demonstrated that the developed method is fit for purpose for the marketed products. The NMR method was extended to the analysis of methylsulfonylmethane, adulterant maltodextrin, acetate and inorganic ions. Low-field NMR can be a quicker and cheaper alternative to more expensive high-field NMR measurements for quality control of the investigated dietary supplements. High-field NMR instrumentation can be more favorable for samples with complex composition due to better resolution, simultaneously giving the possibility of analysis of inorganic species such as potassium and chloride.
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Affiliation(s)
- Klaudia Adels
- Department of Chemistry and Biotechnology, FH Aachen University of Applied Sciences, Heinrich-Mußmann-Straße 1-5, 52428, Jülich, Germany
| | - Gereon Elbers
- Department of Chemistry and Biotechnology, FH Aachen University of Applied Sciences, Heinrich-Mußmann-Straße 1-5, 52428, Jülich, Germany
| | - Bernd Diehl
- Spectral Service AG, Emil-Hoffmann-Straße 33, 50996, Cologne, Germany
| | - Yulia Monakhova
- Department of Chemistry and Biotechnology, FH Aachen University of Applied Sciences, Heinrich-Mußmann-Straße 1-5, 52428, Jülich, Germany.
- Spectral Service AG, Emil-Hoffmann-Straße 33, 50996, Cologne, Germany.
- Institute of Chemistry, Saratov State University, Astrakhanskaya Street 83, 410012, Saratov, Russia.
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Becht A, Schollmayer C, Monakhova Y, Holzgrabe U. Tracing the origin of paracetamol tablets by near-infrared, mid-infrared, and nuclear magnetic resonance spectroscopy using principal component analysis and linear discriminant analysis. Anal Bioanal Chem 2021; 413:3107-3118. [PMID: 33730203 PMCID: PMC8043955 DOI: 10.1007/s00216-021-03249-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 02/18/2021] [Accepted: 02/22/2021] [Indexed: 11/26/2022]
Abstract
Most drugs are no longer produced in their own countries by the pharmaceutical companies, but by contract manufacturers or at manufacturing sites in countries that can produce more cheaply. This not only makes it difficult to trace them back but also leaves room for criminal organizations to fake them unnoticed. For these reasons, it is becoming increasingly difficult to determine the exact origin of drugs. The goal of this work was to investigate how exactly this is possible by using different spectroscopic methods like nuclear magnetic resonance and near- and mid-infrared spectroscopy in combination with multivariate data analysis. As an example, 56 out of 64 different paracetamol preparations, collected from 19 countries around the world, were chosen to investigate whether it is possible to determine the pharmaceutical company, manufacturing site, or country of origin. By means of suitable pre-processing of the spectra and the different information contained in each method, principal component analysis was able to evaluate manufacturing relationships between individual companies and to differentiate between production sites or formulations. Linear discriminant analysis showed different results depending on the spectral method and purpose. For all spectroscopic methods, it was found that the classification of the preparations to their manufacturer achieves better results than the classification to their pharmaceutical company. The best results were obtained with nuclear magnetic resonance and near-infrared data, with 94.6%/99.6% and 98.7/100% of the spectra of the preparations correctly assigned to their pharmaceutical company or manufacturer. ![]()
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Affiliation(s)
- Alexander Becht
- Institute for Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Curd Schollmayer
- Institute for Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Yulia Monakhova
- Faculty of Chemistry and Biotechnology, Aachen University of Applied Sciences, 52428, Jülich, Germany
- Institute of Chemistry, Saratov State University, Astrakhanskaya Street 83, 410012, Saratov, Russia
| | - Ulrike Holzgrabe
- Institute for Pharmacy and Food Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
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Bergs M, Monakhova Y, Diehl BW, Konow C, Völkering G, Pude R, Schulze M. Lignins Isolated via Catalyst-Free Organosolv Pulping from Miscanthus x giganteus, M. sinensis, M. robustus and M. nagara: A Comparative Study. Molecules 2021; 26:842. [PMID: 33562747 PMCID: PMC7915034 DOI: 10.3390/molecules26040842] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 01/21/2021] [Accepted: 02/02/2021] [Indexed: 01/30/2023] Open
Abstract
As a low-input crop, Miscanthus offers numerous advantages that, in addition to agricultural applications, permits its exploitation for energy, fuel, and material production. Depending on the Miscanthus genotype, season, and harvest time as well as plant component (leaf versus stem), correlations between structure and properties of the corresponding isolated lignins differ. Here, a comparative study is presented between lignins isolated from M. x giganteus, M. sinensis, M. robustus and M. nagara using a catalyst-free organosolv pulping process. The lignins from different plant constituents are also compared regarding their similarities and differences regarding monolignol ratio and important linkages. Results showed that the plant genotype has the weakest influence on monolignol content and interunit linkages. In contrast, structural differences are more significant among lignins of different harvest time and/or season. Analyses were performed using fast and simple methods such as nuclear magnetic resonance (NMR) spectroscopy. Data was assigned to four different linkages (A: β-O-4 linkage, B: phenylcoumaran, C: resinol, D: β-unsaturated ester). In conclusion, A content is particularly high in leaf-derived lignins at just under 70% and significantly lower in stem and mixture lignins at around 60% and almost 65%. The second most common linkage pattern is D in all isolated lignins, the proportion of which is also strongly dependent on the crop portion. Both stem and mixture lignins, have a relatively high share of approximately 20% or more (maximum is M. sinensis Sin2 with over 30%). In the leaf-derived lignins, the proportions are significantly lower on average. Stem samples should be chosen if the highest possible lignin content is desired, specifically from the M. x giganteus genotype, which revealed lignin contents up to 27%. Due to the better frost resistance and higher stem stability, M. nagara offers some advantages compared to M. x giganteus. Miscanthus crops are shown to be very attractive lignocellulose feedstock (LCF) for second generation biorefineries and lignin generation in Europe.
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Affiliation(s)
- Michel Bergs
- Department of Natural Sciences, Bonn-Rhein-Sieg University of Applied Sciences, von-Liebig-Strasse 20, D-53359 Rheinbach, Germany;
- Spectral Service AG, Emil-Hoffmann-Strasse 33, D-50996 Köln, Germany;
| | - Yulia Monakhova
- Institute of Chemistry, Saratov State University, Astrakhanskaya Street 83, 410012 Saratov, Russia;
- Department of Natural Sciences, University of Applied Sciences Aachen, Chemistry and Biotechnology, Heinrich-Mußmann-Strasse 1, 52428 Jülich, Germany
| | - Bernd W. Diehl
- Spectral Service AG, Emil-Hoffmann-Strasse 33, D-50996 Köln, Germany;
| | - Christopher Konow
- Department of Chemistry, MS 015, Brandeis University, 415 South Street, Waltham, MA 02453, USA;
| | - Georg Völkering
- Institute of Crop Science and Resource Conservation (INRES), Faculty of Agriculture, University of Bonn, Klein-Altendorf 2, D-53359 Rheinbach, Germany; (G.V.); (R.P.)
| | - Ralf Pude
- Institute of Crop Science and Resource Conservation (INRES), Faculty of Agriculture, University of Bonn, Klein-Altendorf 2, D-53359 Rheinbach, Germany; (G.V.); (R.P.)
- Field Lab Campus Klein-Altendorf, Faculty of Agriculture, University of Bonn, Campus Klein-Altendorf 1, D-53359 Rheinbach, Germany
| | - Margit Schulze
- Department of Natural Sciences, Bonn-Rhein-Sieg University of Applied Sciences, von-Liebig-Strasse 20, D-53359 Rheinbach, Germany;
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Bergs M, Do XT, Rumpf J, Kusch P, Monakhova Y, Konow C, Völkering G, Pude R, Schulze M. Comparing chemical composition and lignin structure of Miscanthus x giganteus and Miscanthus nagara harvested in autumn and spring and separated into stems and leaves. RSC Adv 2020; 10:10740-10751. [PMID: 35492943 PMCID: PMC9050404 DOI: 10.1039/c9ra10576j] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 03/09/2020] [Indexed: 02/05/2023] Open
Abstract
Miscanthus crops possess very attractive properties such as high photosynthesis yield and carbon fixation rate. Because of these properties, it is currently considered for use in second-generation biorefineries. Here we analyze the differences in chemical composition between M. x giganteus, a commonly studied Miscanthus genotype, and M. nagara, which is relatively understudied but has useful properties such as increased frost resistance and higher stem stability. Samples of M. x giganteus (Gig35) and M. nagara (NagG10) have been separated by plant portion (leaves and stems) in order to isolate the corresponding lignins. The organosolv process was used for biomass pulping (80% ethanol solution, 170 °C, 15 bar). Biomass composition and lignin structure analysis were performed using composition analysis, Fourier-transform infrared (FTIR), ultraviolet-visible (UV-Vis) and nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analysis (TGA), size exclusion chromatography (SEC) and pyrolysis gas-chromatography/mass spectrometry (Py-GC/MS) to determine the 3D structure of the isolated lignins, monolignol ratio and most abundant linkages depending on genotype and harvesting season. SEC data showed significant differences in the molecular weight and polydispersity indices for stem versus leaf-derived lignins. Py-GC/MS and hetero-nuclear single quantum correlation (HSQC) NMR revealed different monolignol compositions for the two genotypes (Gig35, NagG10). The monolignol ratio is slightly influenced by the time of harvest: stem-derived lignins of M. nagara showed increasing H and decreasing G unit content over the studied harvesting period (December–April). Miscanthus crops possess attractive properties such as high photosynthesis yield and carbon fixation rate. Moreover, M. nagara, shows good frost tolerance. Monolignol ratio and most abundant linkages of the isolated lignins have been identified.![]()
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Affiliation(s)
- Michel Bergs
- Department of Natural Sciences
- Bonn-Rhein-Sieg University of Applied Sciences
- D-53359 Rheinbach
- Germany
- Spectral Service AG
| | - Xuan Tung Do
- Department of Natural Sciences
- Bonn-Rhein-Sieg University of Applied Sciences
- D-53359 Rheinbach
- Germany
| | - Jessica Rumpf
- Department of Natural Sciences
- Bonn-Rhein-Sieg University of Applied Sciences
- D-53359 Rheinbach
- Germany
| | - Peter Kusch
- Department of Natural Sciences
- Bonn-Rhein-Sieg University of Applied Sciences
- D-53359 Rheinbach
- Germany
| | - Yulia Monakhova
- Spectral Service AG
- Germany
- Institute of Chemistry
- Saratov State University
- 410012 Saratov
| | | | - Georg Völkering
- Institute of Crop Science and Resource Conservation
- Faculty of Agriculture
- University of Bonn
- D-53359 Rheinbach
- Germany
| | - Ralf Pude
- Institute of Crop Science and Resource Conservation
- Faculty of Agriculture
- University of Bonn
- D-53359 Rheinbach
- Germany
| | - Margit Schulze
- Department of Natural Sciences
- Bonn-Rhein-Sieg University of Applied Sciences
- D-53359 Rheinbach
- Germany
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Abstract
The quantification of a drug, its impurities, and e.g. components of a mixture has become routine in NMR laboratories and many applications have been described in the literature. However, besides simply using 1D 1H or 13C NMR, a number of more advanced methods has been developed and used in the past. Here, we want to describe the applicability of nuclei beyond the classical ones 1H and 13C. Mixtures can be characterized much better by applying various chemometric methods and separating the signals of mixture components can be achieved by DOSY experiments. All these methods contribute to the platform of qNMR methods and extend the possibilities of NMR for quantification and quality evaluation of drugs, excipients, polymers, and plant extracts. However, for quantification purposes, validation is always an issue and it is necessary to think about taking NMR related measures which might be different from the ones considered for chromatographic methods.
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Affiliation(s)
- Bernd Diehl
- Spectral Service AG, Emil-Hoffmann-Str. 33, 50996, Cologne, Germany
| | - Ulrike Holzgrabe
- Institute of Pharmacy, University of Wuerzburg, Am Hubland, 97074, Wuerzburg, Germany.
| | - Yulia Monakhova
- Spectral Service AG, Emil-Hoffmann-Str. 33, 50996, Cologne, Germany; Institute of Chemistry, Saratov State University, Astrakhanskaya Street 83, 410012, Saratov, Russia; Institute of Chemistry, Saint Petersburg State University, 13B Universitetskaya Emb., St Petersburg, 199034, Russia
| | - Torsten Schönberger
- Bundeskriminalamt, Forensic Science Institute, KT43 - Central Analytics II, 65173 Wiesbaden, Germany
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Bergs M, Völkering G, Kraska T, Pude R, Do XT, Kusch P, Monakhova Y, Konow C, Schulze M. Miscanthus x giganteus Stem Versus Leaf-Derived Lignins Differing in Monolignol Ratio and Linkage. Int J Mol Sci 2019; 20:E1200. [PMID: 30857288 PMCID: PMC6429407 DOI: 10.3390/ijms20051200] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/28/2019] [Accepted: 03/05/2019] [Indexed: 11/19/2022] Open
Abstract
As a renewable, Miscanthus offers numerous advantages such as high photosynthesis activity (as a C₄ plant) and an exceptional CO₂ fixation rate. These properties make Miscanthus very attractive for industrial exploitation, such as lignin generation. In this paper, we present a systematic study analyzing the correlation of the lignin structure with the Miscanthus genotype and plant portion (stem versus leaf). Specifically, the ratio of the three monolignols and corresponding building blocks as well as the linkages formed between the units have been studied. The lignin amount has been determined for M. x giganteus (Gig17, Gig34, Gig35), M. nagara (NagG10), M. sinensis (Sin2), and M. robustus (Rob4) harvested at different time points (September, December, and April). The influence of the Miscanthus genotype and plant component (leaf vs. stem) has been studied to develop corresponding structure-property relationships (i.e., correlations in molecular weight, polydispersity, and decomposition temperature). Lignin isolation was performed using non-catalyzed organosolv pulping and the structure analysis includes compositional analysis, Fourier transform infradred (FTIR), ultraviolet/visible (UV-Vis), hetero-nuclear single quantum correlation nuclear magnetic resonsnce (HSQC-NMR), thermogravimetric analysis (TGA), and pyrolysis gaschromatography/mass spectrometry (GC/MS). Structural differences were found for stem and leaf-derived lignins. Compared to beech wood lignins, Miscanthus lignins possess lower molecular weight and narrow polydispersities (<1.5 Miscanthus vs. >2.5 beech) corresponding to improved homogeneity. In addition to conventional univariate analysis of FTIR spectra, multivariate chemometrics revealed distinct differences for aromatic in-plane deformations of stem versus leaf-derived lignins. These results emphasize the potential of Miscanthus as a low-input resource and a Miscanthus-derived lignin as promising agricultural feedstock.
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Affiliation(s)
- Michel Bergs
- Department of Natural Sciences, Bonn-Rhein-Sieg University of Applied Sciences, von-Liebig-Strasse 20, D-53359 Rheinbach, Germany.
- Institute of Crop Science and Resource Conservation, Faculty of Agriculture, University of Bonn, Klein-Altendorf 2, D-53359 Rheinbach, Germany.
| | - Georg Völkering
- Institute of Crop Science and Resource Conservation, Faculty of Agriculture, University of Bonn, Klein-Altendorf 2, D-53359 Rheinbach, Germany.
| | - Thorsten Kraska
- Field Lab Campus Klein-Altendorf, Faculty of Agriculture, University of Bonn, Campus Klein-Altendorf 1, D-53359 Rheinbach, Germany.
| | - Ralf Pude
- Institute of Crop Science and Resource Conservation, Faculty of Agriculture, University of Bonn, Klein-Altendorf 2, D-53359 Rheinbach, Germany.
- Field Lab Campus Klein-Altendorf, Faculty of Agriculture, University of Bonn, Campus Klein-Altendorf 1, D-53359 Rheinbach, Germany.
| | - Xuan Tung Do
- Department of Natural Sciences, Bonn-Rhein-Sieg University of Applied Sciences, von-Liebig-Strasse 20, D-53359 Rheinbach, Germany.
| | - Peter Kusch
- Department of Natural Sciences, Bonn-Rhein-Sieg University of Applied Sciences, von-Liebig-Strasse 20, D-53359 Rheinbach, Germany.
| | - Yulia Monakhova
- Spectral Service AG, Emil-Hoffmann-Strasse 33, D-50996 Köln, Germany.
- Institute of Chemistry, Saratov State University, Astrakhanskaya Street 83, 410012 Saratov, Russia.
| | - Christopher Konow
- Department of Chemistry, MS 015, Brandeis University, 415 South Street, Waltham, MA 02453, USA.
| | - Margit Schulze
- Department of Natural Sciences, Bonn-Rhein-Sieg University of Applied Sciences, von-Liebig-Strasse 20, D-53359 Rheinbach, Germany.
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Hohmann M, Monakhova Y, Erich S, Christoph N, Wachter H, Holzgrabe U. Differentiation of Organically and Conventionally Grown Tomatoes by Chemometric Analysis of Combined Data from Proton Nuclear Magnetic Resonance and Mid-infrared Spectroscopy and Stable Isotope Analysis. J Agric Food Chem 2015; 63:9666-9675. [PMID: 26457410 DOI: 10.1021/acs.jafc.5b03853] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Because the basic suitability of proton nuclear magnetic resonance spectroscopy ((1)H NMR) to differentiate organic versus conventional tomatoes was recently proven, the approach to optimize (1)H NMR classification models (comprising overall 205 authentic tomato samples) by including additional data of isotope ratio mass spectrometry (IRMS, δ(13)C, δ(15)N, and δ(18)O) and mid-infrared (MIR) spectroscopy was assessed. Both individual and combined analytical methods ((1)H NMR + MIR, (1)H NMR + IRMS, MIR + IRMS, and (1)H NMR + MIR + IRMS) were examined using principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), linear discriminant analysis (LDA), and common components and specific weight analysis (ComDim). With regard to classification abilities, fused data of (1)H NMR + MIR + IRMS yielded better validation results (ranging between 95.0 and 100.0%) than individual methods ((1)H NMR, 91.3-100%; MIR, 75.6-91.7%), suggesting that the combined examination of analytical profiles enhances authentication of organically produced tomatoes.
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Affiliation(s)
- Monika Hohmann
- Institute of Pharmacy and Food Chemistry, University of Würzburg , Am Hubland, 97074 Würzburg, Germany
- Bavarian Health and Food Safety Authority , Luitpoldstraße 1, 97082 Würzburg, Germany
| | - Yulia Monakhova
- Spectral Service , Emil-Hoffmann-Straße 33, 50996 Cologne, Germany
- Department of Chemistry, Saratov State University , Astrakhanskaya Street 83, 410012 Saratov, Russia
| | - Sarah Erich
- Chemical and Veterinary Investigation Laboratory , Bissierstraße 5, 79114 Freiburg, Germany
| | - Norbert Christoph
- Bavarian Health and Food Safety Authority , Luitpoldstraße 1, 97082 Würzburg, Germany
| | - Helmut Wachter
- Bavarian Health and Food Safety Authority , Luitpoldstraße 1, 97082 Würzburg, Germany
| | - Ulrike Holzgrabe
- Institute of Pharmacy and Food Chemistry, University of Würzburg , Am Hubland, 97074 Würzburg, Germany
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Mecozzi M, Monakhova Y. Application of multivariate methods in the monitoring of marine environment: simultaneous determination of bromide, bicarbonate, nitrate and sulphide in seawater by ultraviolet spectroscopy. ACTA ACUST UNITED AC 2013. [DOI: 10.1504/ijenvh.2013.054094] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Monakhova Y, Agulhon P, Quignard F, Tanchoux N, Tichit D. New mixed lanthanum- and alkaline-earth cation-containing basic catalysts obtained by an alginate route. Catal Today 2012. [DOI: 10.1016/j.cattod.2012.03.072] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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