1
|
Shiea J, Lin HJ, Bhat SM, Lee CY, Huang MZ, Ponnusamy VK, Cheng SC. Thin layer chromatography/desorption flame-induced atmospheric pressure chemical ionization/mass spectrometry for the analysis of volatile and semi-volatile mixtures. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2022; 36:e9409. [PMID: 36194496 DOI: 10.1002/rcm.9409] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
UNLABELLED Flame-induced atmospheric pressure chemical ionization (FAPCI) has been used to directly characterize chemical compounds on a glass rod and drug tablet surfaces. In this study, FAPCI was further applied to interface thin layer chromatography (TLC) and mass spectrometry (MS) for mixture analysis. METHODS A micro-sized oxyacetylene flame was generated using a small concentric tube system. Hot gas flow and primary reactive species from the micro-flame were directed toward a developed TLC gel plate to thermally desorb and ionize analytes on the gel surface. The resulting analyte ions subsequently entered the MS inlet for detection. RESULTS A 1-1.5-mm-wide light-brown line was observed on the TLC plate after the desorption FAPCI/MS (DFAPCI/MS) analysis, revealing that the gel surface withstood a high temperature from the impact of the micro-flame. Volatile and semi-volatile chemical compounds, including amine and amide standards, drugs, and aromatherapy oils, were successfully desorbed, ionized, and detected using this TLC/DFAPCI/MS. The limit of detection of TLC-DFAPCI/MS was determined to be 5 ng/spot for dibenzylamine and ethenzamide. CONCLUSIONS TLC/DFAPCI/MS is one of the simplest TLC-MS interfaces showing the advantages such as low costs and an easy set up. The technique is useful for characterizing thermally stable volatile and semi-volatile compounds in a mixture.
Collapse
Affiliation(s)
- Jentaie Shiea
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, Taiwan
- Rapid Screening Research Center for Toxicology and Biomedicine, National Sun Yat-Sen University, Kaohsiung, Taiwan
- Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hsing-Jung Lin
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan
| | | | - Chi-Yang Lee
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Min-Zong Huang
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Vinoth Kumar Ponnusamy
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Sy-Chyi Cheng
- Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan, Taiwan
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| |
Collapse
|
2
|
Advances in analytical techniques coupled to in vitro bioassays in the search for new peptides with functional activity in effect-directed analysis. Food Chem 2022; 397:133784. [DOI: 10.1016/j.foodchem.2022.133784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 07/17/2022] [Accepted: 07/23/2022] [Indexed: 11/20/2022]
|
3
|
Móricz ÁM, Ott PG, Krüzselyi D, Baglyas M, Morlock GE. High-performance thin-layer chromatography–direct bioautography combined with chemometrics for the distinction of goldenrod species. JPC-J PLANAR CHROMAT 2022. [DOI: 10.1007/s00764-022-00159-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
AbstractThirteen root extract samples of four goldenrod (Solidago) species present in Europe were investigated by hyphenated high-performance thin-layer chromatography (HPTLC). Only S. virgaurea is native, whereas S. gigantea, S. canadensis, and S. graminifolia have been introduced from North America. The bioactive zones in the Aliivibrio fischeri bioautogram were identified as polyacetylenes, labdane diterpenes, or clerodane diterpenes by HPTLC coupled to high-resolution mass spectrometry, exploiting the two interfaces, heated electrospray ionization, and direct analysis in real time. Principal component analysis of the obtained bioprofiles enabled the discrimination of the Solidago species. Furthermore, chemometrics pointed to the discriminative components, the main bioactive markers of the species: Z,Z-matricaria ester from S. virgaurea, solidagenone from S. canadensis, solidagoic acid A, and a dialdehyde clerodane diterpene from S. gigantea, and Z-dehydromatricaria ester from S. graminifolia.
Collapse
|
4
|
Krüzselyi D, Bakonyi J, Ott PG, Darcsi A, Csontos P, Morlock GE, Móricz ÁM. Goldenrod Root Compounds Active against Crop Pathogenic Fungi. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:12686-12694. [PMID: 34665636 DOI: 10.1021/acs.jafc.1c03676] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Root extracts of three goldenrods were screened for antimicrobial compounds. 2Z,8Z- and 2E,8Z-matricaria esters from European goldenrod (Solidago virgaurea) and E- and Z-dehydromatricaria esters from grass-leaved goldenrod (Solidago graminifolia) and first from showy goldenrod (Solidago speciosa) were identified by high-performance thin-layer chromatography combined with effect-directed analysis and high-resolution mass spectrometry or nuclear magnetic resonance spectroscopy after liquid chromatographic fractionation and isolation. Next to their antibacterial effects (against Bacillus subtilis, Aliivibrio fischeri, and Pseudomonas syringae pv. maculicola), they inhibited the crop pathogenic fungi Fusarium avenaceum and Bipolaris sorokiniana with half maximal inhibitory concentrations (IC50) between 31 and 107 μg/mL. Benzyl 2-hydroxy-6-methoxybenzoate, for the first time found in showy goldenrod root, showed the strongest antifungal effect, with IC50 of 25-26 μg/mL for both fungal strains.
Collapse
Affiliation(s)
- Dániel Krüzselyi
- Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network (ELKH), Herman Ottó Street 15, 1022 Budapest, Hungary
| | - József Bakonyi
- Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network (ELKH), Herman Ottó Street 15, 1022 Budapest, Hungary
| | - Péter G Ott
- Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network (ELKH), Herman Ottó Street 15, 1022 Budapest, Hungary
| | - András Darcsi
- Pharmaceutical Chemistry and Technology Department, National Institute of Pharmacy and Nutrition, Zrínyi Street 3, 1051 Budapest, Hungary
| | - Péter Csontos
- Institute for Soil Sciences, Centre for Agricultural Research, Eötvös Loránd Research Network (ELKH), Herman Ottó Street 15, 1022 Budapest, Hungary
| | - Gertrud E Morlock
- Chair of Food Science, Institute of Nutritional Science, and TransMIT Center of Effect-Directed Analysis, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| | - Ágnes M Móricz
- Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network (ELKH), Herman Ottó Street 15, 1022 Budapest, Hungary
| |
Collapse
|
5
|
Morlock GE. High-performance thin-layer chromatography combined with effect-directed assays and high-resolution mass spectrometry as an emerging hyphenated technology: A tutorial review. Anal Chim Acta 2021; 1180:338644. [DOI: 10.1016/j.aca.2021.338644] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 12/11/2022]
|
6
|
Kruse S, Pierre F, Morlock G. Imaging high-performance thin-layer chromatography as powerful tool to visualize metabolite profiles of eight Bacillus candidates upon cultivation and growth behavior. J Chromatogr A 2021; 1640:461929. [PMID: 33610132 DOI: 10.1016/j.chroma.2021.461929] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 01/11/2021] [Accepted: 01/18/2021] [Indexed: 01/08/2023]
Abstract
Imaging high-performance thin-layer chromatography (HPTLC) was explored with regard to its ability to visualize changes in the metabolite profile of bacteria. Bacillus subtilis has become a model organism in many fields. The increasing interest in these bacteria is driven by their attributed probiotic activity. However, growth behavior and metabolism of Bacillus species have a considerable influence on their activity and secondary metabolite profile. On the HPTLC plate, cultivation broths of Bacillus species (B. subtilis, B. licheniformis, B. pumilus and B. amyloliquefaciens) and some B. subtilis strains of high genetic similarity up to 99.5% were applied directly and compared with their respective liquid-liquid extracts. The latter as well as the cultivation in a minimal medium reduced the matrix load and improved the zone resolution. Cultivation parameters such as nutrient supply, cultivation temperature, cultivation time and rotational speed (oxygen level) as well as medium change were shown to have a considerable influence on the growth behavior and resulting metabolite profiles. Imaging HPTLC turned out to be an efficient and affordable tool to visualize such influences of cultivation parameters on the metabolite profiles. It converts the complexity of reaction processes occurring during cell cultivation in easy-to-understand images, which are helpful to figure out factors of influence and understand activity changes. The results highlighted that optimal cultivation conditions need to be found for the intended bacterial application, and in particular, these conditions have to be kept constant. It must be ensured that small variations in cultivation parameters of bacteria do not change the specified (probiotic) effect on the health of animals and humans. The HPTLC metabolite profiles represented the cultivation conditions of specific bacteria and were found to be a proof of the activity of distinct bacteria. In addition, HPTLC can also be used to optimize and streamline the culture media. The quality control of cultivation or fermentation processes can benefit from such a powerful tool, as a picture is worth a thousand words.
Collapse
Affiliation(s)
- Stefanie Kruse
- Chair of Food Science, Institute of Nutritional Science, and Interdisciplinary Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| | - Francis Pierre
- Adisseo France S.A.S, Immeuble Anthony Parc 2, 10 Place du Général de Gaulle, 92160 Antony, France
| | - Gertrud Morlock
- Chair of Food Science, Institute of Nutritional Science, and Interdisciplinary Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
| |
Collapse
|
7
|
Häbe TT, Morlock GE. Open-source add-on kit for automation of zone elution in planar chromatography. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2020; 34:e8631. [PMID: 31658504 DOI: 10.1002/rcm.8631] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 10/05/2019] [Accepted: 10/06/2019] [Indexed: 06/10/2023]
Abstract
RATIONALE High-throughput capacity, maximal efficiency and automation are missing key features for thin-layer chromatography/high-performance thin-layer chromatography-mass spectrometry (TLC/HPTLC-MS) hyphenations. So far, commercial interfaces have been operated without an automated positioning system. Hence, a 3D-printed, fully automated, open-source add-on user interface was built for elution-head-based TLC/HPTLC-MS. METHODS Precise plate movement, batch-wise zone elution, and cleaning processes were automated and synchronized with MS data acquisition. The elution head cleaning was made adjustable in intensity and interval, and remaining elution solvent or particles were thoroughly blown out of the MS transfer line. An adjustable short gas beam across the elution zone was integrated to avoid contamination or leakage by released layer particles, or zone distortion by residual eluent flow when lifting the elution head. RESULTS By clicking on zones on the chromatogram, these were selected for consecutive automated positioning below the elution head, sealing and elution. Mean spatial deviations of the positioning on 294 target zones were determined to be 160 μm for track-wise and 190 μm for randomized zone positioning order. Reproducibility of the elution of butyl paraben zones (5.4%, 10 ng/band, n = 70) and its quantitative performance (R2 = 0.992-0.999, 5-50 ng/band) were proven. CONCLUSIONS The stand-alone electronic system design and the compact footprint were achieved by a minimalistic positioning system and internally installed valves. The open-source OC_manager software opened new perspectives in terms of combining MS data evaluation with previous HPTLC results. The successfully demonstrated TLC/HPTLC-MS automation presents a highly efficient, user-independent hyphenation for a broad range of application fields.
Collapse
Affiliation(s)
- Tim T Häbe
- Chair of Food Science, Institute of Nutritional Science, and Interdisciplinary Research Center (iFZ), Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany
| | - Gertrud E Morlock
- Chair of Food Science, Institute of Nutritional Science, and Interdisciplinary Research Center (iFZ), Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany
| |
Collapse
|
8
|
Sherma J, Rabel F. Review of advances in planar chromatography-mass spectrometry published in the period 2015–2019. J LIQ CHROMATOGR R T 2020. [DOI: 10.1080/10826076.2020.1725561] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Joseph Sherma
- Department of Chemistry, Lafayette College, Easton, PA, USA
| | | |
Collapse
|
9
|
Fichou D, Morlock GE. quanTLC, an online open-source solution for videodensitometric quantification. J Chromatogr A 2018; 1560:78-81. [DOI: 10.1016/j.chroma.2018.05.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 05/07/2018] [Accepted: 05/13/2018] [Indexed: 11/26/2022]
|
10
|
Abstract
Food authenticity and food safety are of high importance to organizations as well as to the food industry to ensure an accurate labeling of food products. Respective analytical methods should provide a fast screening and a reliable cost-efficient quantitation. HPTLC was pointed out as key analytical technique in this field. A new HPTLC method applying caffeine-impregnated silica gel plates was developed for eight most frequently found fat-soluble azo dyes unauthorizedly added to spices, spice mixtures, pastes, sauces, and palm oils. A simple post-chromatographic UV irradiation provided an effective sample cleanup, which took 4 min for up to 46 samples in parallel. The method was trimmed to enable 23 simultaneous separations within 20 min for quantitation or 46 separations within 5 min for screening. Linear (4-40 ng/band) or polynomial (10-200 ng/band) calibrations of the eight azo dyes revealed high correlation coefficients and low standard deviations. Limits of detection and quantification were determined to be 2-3 and 6-9 ng/zone, respectively. After an easy sample extraction, recoveries of 70-120% were obtained from chili, paprika, and curcuma powder as well as from chili sauce, curry paste, and palm oil spiked at low (mainly 25-50 mg/kg) and high levels (150-300 mg/kg). For unequivocal identification, the compound in a suspect zone was eluted via a column into the mass spectrometer. This resulted in the hyphenation HPTLC-vis-HPLC-DAD-ESI-MS. Graphical abstract Simplified clean-up by UV irradiation for Sudan dye analysis in food by HPTLC-vis-HPLC-DAD-ESI-MS.
Collapse
|
11
|
Fichou D, Morlock GE. Open-Source-Based 3D Printing of Thin Silica Gel Layers in Planar Chromatography. Anal Chem 2017; 89:2116-2122. [PMID: 28208299 DOI: 10.1021/acs.analchem.6b04813] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
On the basis of open-source packages, 3D printing of thin silica gel layers is demonstrated as proof-of-principle for use in planar chromatography. A slurry doser was designed to replace the plastic extruder of an open-source Prusa i3 printer. The optimal parameters for 3D printing of layers were studied, and the planar chromatographic separations on these printed layers were successfully demonstrated with a mixture of dyes. The layer printing process was fast. For printing a 0.2 mm layer on a 10 cm × 10 cm format, it took less than 5 min. It was affordable, i.e., the running costs for producing such a plate were less than 0.25 Euro and the investment costs for the modified hardware were 630 Euro. This approach demonstrated not only the potential of the 3D printing environment in planar chromatography but also opened new avenues and new perspectives for tailor-made plates, not only with regard to layer materials and their combinations (gradient plates) but also with regard to different layer shapes and patterns. As such an example, separations on a printed plane layer were compared with those obtained from a printed channeled layer. For the latter, 40 channels were printed in parallel on a 10 cm × 10 cm format for the separation of 40 samples. For producing such a channeled plate, the running costs were below 0.04 Euro and the printing process took only 2 min. All modifications of the device and software were released open-source to encourage reuse and improvements and to stimulate the users to contribute to this technology. By this proof-of-principle, another asset was demonstrated to be integrated into the Office Chromatography concept, in which all relevant steps for online miniaturized planar chromatography are performed by a single device.
Collapse
Affiliation(s)
- Dimitri Fichou
- Chair of Food Sciences, Institute of Nutritional Science, and Interdisciplinary Research Center (IFZ), Justus Liebig University Giessen , Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| | - Gertrud E Morlock
- Chair of Food Sciences, Institute of Nutritional Science, and Interdisciplinary Research Center (IFZ), Justus Liebig University Giessen , Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| |
Collapse
|
12
|
Winter GT, Wilhide JA, LaCourse WR. Molecular Ionization-Desorption Analysis Source (MIDAS) for Mass Spectrometry: Thin-Layer Chromatography. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:352-358. [PMID: 26471042 DOI: 10.1007/s13361-015-1289-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 09/30/2015] [Accepted: 10/03/2015] [Indexed: 06/05/2023]
Abstract
Molecular ionization-desorption analysis source (MIDAS), which is a desorption atmospheric pressure chemical ionization (DAPCI) type source, for mass spectrometry has been developed as a multi-functional platform for the direct sampling of surfaces. In this article, its utility for the analysis of thin-layer chromatography (TLC) plates is highlighted. Amino acids, which are difficult to visualize without staining reagents or charring, were detected and identified directly from a TLC plate. To demonstrate the full potential of MIDAS, all active ingredients from an analgesic tablet, separated on a TLC plate, were successfully detected using both positive and negative ion modes. The identity of each of the compounds was confirmed from their mass spectra and compared against standards. Post separation, the chemical signal (blue permanent marker) as reference marks placed at the origin and solvent front were used to calculate retention factor (Rf) values from the resulting ion chromatogram. The quantitative capabilities of the device were exhibited by scanning caffeine spots on a TLC plate of increasing sample amount. A linear curve based on peak are, R2 = 0.994, was generated for seven spots ranging from 50 to 1000 ng of caffeine per spot.
Collapse
Affiliation(s)
- Gregory T Winter
- University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | | | | |
Collapse
|
13
|
Shen T, Morlock G, Zorn H. Production of cyathane type secondary metabolites by submerged cultures of Hericium erinaceus and evaluation of their antibacterial activity by direct bioautography. Fungal Biol Biotechnol 2015; 2:8. [PMID: 28955459 PMCID: PMC5611583 DOI: 10.1186/s40694-015-0018-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 12/09/2015] [Indexed: 11/18/2022] Open
Abstract
Background Fungi of the phylum Basidiomycota are well-known to form a broad spectrum of biologically active secondary metabolites, especially low molecular weight compounds such as terpenoids. Hericium erinaceus produces various cyathane type diterpenoids including erinacines. However, no quantitative data and production kinetics have been reported on the biosynthesis of the erinacines C and P in submerged cultures. In the present study, the production of erinacine C was optimized, and the product formation kinetics as well as the antimicrobial activity were studied by high-performance liquid chromatography (HPLC), high-performance thin-layer chromatography (HPTLC) and direct bioautography. Results Oatmeal and Edamin® K were identified to be crucial media components for an efficient production of erinacine C. The highest concentrations of erinacine C were obtained in the optimized culture medium on the 9th culture day (approximately 260 mg L−1). The production of erinacine P was strongly time dependent. The maximum concentration of erinacine P of 184 mg L−1 was observed on the third culture day. Afterwards, the concentrations of erinacine P decreased while the concentrations of erinacine C steadily increased. Comparable results were obtained by HPTLC with UV detection and HPLC with diode-array detection (DAD) analyses. Direct bioautography allowed for an additional analysis of the antimicrobial activity of the secondary metabolites. Conclusions The C and N sources oatmeal and Edamin® K induced the formation of erinacine C. Detailed product formation kinetics of the erinacines C and P have been reported for the first time. HPTLC combined with the Aliivibrio fischeri bioassay allowed for an instant detection of cyathane diterpenoids in crude extracts and for an evaluation of the antimicrobial activity of the secondary metabolites directly on the plate. Electronic supplementary material The online version of this article (doi:10.1186/s40694-015-0018-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- T Shen
- Institute of Food Chemistry and Food Biotechnology, Justus Liebig University Giessen, Heinrich-Buff-Ring 17, 35392 Giessen, Germany
| | - G Morlock
- Institute of Nutritional Science, and Interdisciplinary Research Center for Biosystems, Land Use and Nutrition, Justus Liebig University Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| | - H Zorn
- Institute of Food Chemistry and Food Biotechnology, Justus Liebig University Giessen, Heinrich-Buff-Ring 17, 35392 Giessen, Germany
| |
Collapse
|
14
|
Kanyal SS, Häbe TT, Cushman CV, Dhunna M, Roychowdhury T, Farnsworth PB, Morlock GE, Linford MR. Microfabrication, separations, and detection by mass spectrometry on ultrathin-layer chromatography plates prepared via the low-pressure chemical vapor deposition of silicon nitride onto carbon nanotube templates. J Chromatogr A 2015; 1404:115-23. [DOI: 10.1016/j.chroma.2015.05.053] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 05/21/2015] [Accepted: 05/21/2015] [Indexed: 11/26/2022]
|