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Gertrud E Morlock - One of the best experts on this subject based on the ideXlab platform.
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Planar Chromatography Mass Spectrometry
Reference Module in Chemistry Molecular Sciences and Chemical Engineering, 2020Co-Authors: Gertrud E MorlockAbstract:Coupling of Planar Chromatography with mass spectrometry (thin-layer Chromatography/high-performance thin-layer Chromatography-mass spectrometry (TLC/HPTLC-MS)) allows highly targeted recording of mass spectra, only of zones of interest. Owed to the locally fixed, separated compound zones on the adsorbent, antecedent evaluation is allowed. MS system contaminations through matrix, background, or negative samples are reduced to a minimum. In addition to targeted recording of zones of interest, e.g. with the TLC-MS Interface or liquid extraction surface analysis, a whole track of hR F -substance window can be scanned via matrix-assisted laser desorption ionisation or via ambient MS techniques like desorption electrospray ionization and direct analysis in real time, all under the precondition of a high spatial resolution and a satisfying detectability in the low nanogram per band range.
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In-process quality control of wine by Planar Chromatography versus micro Planar Chromatography
Journal of Chromatography A, 2018Co-Authors: Simone Kirchert, R.e. Kaiser, Gertrud E MorlockAbstract:Abstract High-performance thin-layer Chromatography (HPTLC) methods were developed to determine glycerol, gluconic acid, amino acids and sugars for in-process quality control of wine. Twenty wine samples (Pfalz region, Germany) were diluted with methanol and used for quantitative analysis without any further sample preparation. The developed amino acid method provided quantitative and characteristic fingerprints of wine varieties. The amino acid assignments were verified by HPTLC-MS. The developed gluconic acid method was primarily used to control the threshold, indicating a Botrytis cinerea infection of grapes. However, this method also enabled the detection of further organic acids like malic, tartaric and citric acids. A glycerol method was developed for control of the grape must fermentation (spontaneous/regular) and for fraud detection (glycerol adulteration). The HPTLC results of the sugar contents in the wine samples were similar to those of the well-known Luff-Schoorl method. The combined use of these developed HPTLC methods allowed the fermentation control (e.g., alcoholic and malolactic fermentation) and the monitoring of the grapes’ overall health status. Without modification, the HPTLC methods for sugar and amino acid analysis could be transferred to circular micro Planar Chromatography (μ-PLC), showing its potential and benefits in terms of an inexpensive alternative for wineries and distributors.
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office Chromatography miniaturized all in one open source system for Planar Chromatography
Analytical Chemistry, 2018Co-Authors: Dimitri Fichou, Gertrud E MorlockAbstract:Current high-performance-thin-layer-Chromatography instrumentation is offline and stepwise automated. However, moderate miniaturization offers many advantages and together with the transfer of modern print and media technologies to the field of Chromatography (office Chromatography) it opens up new avenues. This is demonstrated in an all-in-one open-source system developed for Planar Chromatography and especially for ultrathin-layer Chromatography. Using an InkShield board to control a thermal inkjet cartridge, picoliter drops were printed at a resolution of 96 dpi on the adsorbent layer. Using Marlin, a popular firmware in 3D printing, Cartesian movement of the print head was made possible for full control of the printing process. Open-source software was developed to control the device in each operation step. Sample solutions and mobile phase were inkjet-printed, exemplarily shown for the analysis of dye- or paraben-mixture solutions. Light-emitting diodes (LEDs) were investigated for documentation. For...
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open source based 3d printing of thin silica gel layers in Planar Chromatography
Analytical Chemistry, 2017Co-Authors: Dimitri Fichou, Gertrud E MorlockAbstract: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 pa...
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Miniaturization of Instrumental Planar Chromatography with Focus on Mass Spectrometry
Chromatographia, 2016Co-Authors: Tim T. Häbe, Gertrud E MorlockAbstract:The universal trends to miniaturization and to automation of technologies affect the further development of analytical instrumentation and methodologies. In Planar Chromatography, these trends are characterized by decreasing dimensions and thickness of the stationary phase and the development of respectively tailored equipment. The miniaturization of instrumental Planar Chromatography is reflected in the interdisciplinary office Chromatography concept, in which achievements in office technologies (print and media technologies) and miniaturized layer developments are integrated. The office Chromatography concept stimulates research towards miniaturization and will at last implement a fully online miniaturized system. The use of print techniques is still at its infancy in separation science, whereas printing of materials already became an accepted tool in the life sciences. Commercially, available printers were used for sample application on miniaturized plates and were stepwise modified for a precise and quantitative performance. Further miniaturization attempts led to miniaturized layers with different physical and chromatographic properties. The method transfer to such ultrathin-layer Chromatography (UTLC) plates demonstrated the synergetic potential of this instrumental concept. Detection and evaluation tools have to be adjusted and integrated, too. Since the beginning of this millennium, several ionization techniques have been introduced or improved, and paved the way for mass spectrometry (MS) directly from miniaturized surfaces. UTLC was already coupled to MS via several ion source interfaces, such as secondary ionization, matrix-assisted laser desorption and ionization, electrospray ionization, desorption electrospray ionization and direct analysis in real time. However, the hyphenation to targeted, scanning or imaging MS still requires adaptations and methodic efforts to utilize UTLC layers.
Rafael Kandiyoti - One of the best experts on this subject based on the ideXlab platform.
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comparison of the fractionation of a coal tar pitch by solvent solubility and by Planar Chromatography
Fuel, 1999Co-Authors: María J. Lázaro, Alan A. Herod, Rafael KandiyotiAbstract:Abstract Two methods of fractionation of a coal tar pitch, one based on solvent solubility separation and the other on preparative thin layer Chromatography were compared for effectiveness of the separation. The fractions were characterised using size exclusion Chromatography (SEC) and UV-fluorescence spectroscopy (UV-F). Fractionation by Planar Chromatography was found to give a better separation and to use less solvent than the solvent separation method. Both SEC and UV-F clearly showed less overlap in fractions separated by Planar Chromatography, compared to solvent fractionation. The cleaner separation of the heaviest fraction is particularly relevant for the mass spectroscopic investigation of large molecular mass materials, where the presence of lighter materials was observed to suppress high-mass signal. The close agreement observed between SEC and UV-F is consistent with previously reported correlations for coal tar pitches. However, the relevant SEC work was performed using pyridine as the mobile phase. We have found that 10%–15% of coal tar pitches cannot be dissolved in pyridine whilst total dissolution of coal tar pitch may be achieved using NMP. The calibration of analytical columns operated with NMP would be expected to lead to more accurate evaluations of molecular masses in these complex mixtures.
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fractionation of a wood tar pitch by Planar Chromatography for the characterisation of large molecular mass materials
Journal of Chromatography A, 1999Co-Authors: María J. Lázaro, Alan A. Herod, M Domin, Rafael KandiyotiAbstract:Abstract A commercial tar pitch derived from pine wood – Massen Pine (Pinus Massonia) and sold as Stockholm tar has been fractionated by Planar Chromatography with examination of the fractions by size exclusion Chromatography in NMP eluent, by UV-fluorescence and by matrix assisted laser desorption mass spectrometry. The relatively small molecules, mobile in Planar Chromatography, are shown to be non-polar. Large molecules were found in each fraction, corresponding in SEC elution times up to polystyrenes of molecular mass of at least 1.8 million. Size exclusion Chromatography profiles by UV light absorbance showed differences in relative absorbance of different wavelengths for large and small molecules, implying differences in structures. MALDI mass spectra indicated molecules of mass of several thousand mass units with the upper limit of mass not defined. Planar Chromatography provides a fast, cheap method of isolating large molecular mass fractions of this biomass tar.
María J. Lázaro - One of the best experts on this subject based on the ideXlab platform.
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comparison of the fractionation of a coal tar pitch by solvent solubility and by Planar Chromatography
Fuel, 1999Co-Authors: María J. Lázaro, Alan A. Herod, Rafael KandiyotiAbstract:Abstract Two methods of fractionation of a coal tar pitch, one based on solvent solubility separation and the other on preparative thin layer Chromatography were compared for effectiveness of the separation. The fractions were characterised using size exclusion Chromatography (SEC) and UV-fluorescence spectroscopy (UV-F). Fractionation by Planar Chromatography was found to give a better separation and to use less solvent than the solvent separation method. Both SEC and UV-F clearly showed less overlap in fractions separated by Planar Chromatography, compared to solvent fractionation. The cleaner separation of the heaviest fraction is particularly relevant for the mass spectroscopic investigation of large molecular mass materials, where the presence of lighter materials was observed to suppress high-mass signal. The close agreement observed between SEC and UV-F is consistent with previously reported correlations for coal tar pitches. However, the relevant SEC work was performed using pyridine as the mobile phase. We have found that 10%–15% of coal tar pitches cannot be dissolved in pyridine whilst total dissolution of coal tar pitch may be achieved using NMP. The calibration of analytical columns operated with NMP would be expected to lead to more accurate evaluations of molecular masses in these complex mixtures.
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fractionation of a wood tar pitch by Planar Chromatography for the characterisation of large molecular mass materials
Journal of Chromatography A, 1999Co-Authors: María J. Lázaro, Alan A. Herod, M Domin, Rafael KandiyotiAbstract:Abstract A commercial tar pitch derived from pine wood – Massen Pine (Pinus Massonia) and sold as Stockholm tar has been fractionated by Planar Chromatography with examination of the fractions by size exclusion Chromatography in NMP eluent, by UV-fluorescence and by matrix assisted laser desorption mass spectrometry. The relatively small molecules, mobile in Planar Chromatography, are shown to be non-polar. Large molecules were found in each fraction, corresponding in SEC elution times up to polystyrenes of molecular mass of at least 1.8 million. Size exclusion Chromatography profiles by UV light absorbance showed differences in relative absorbance of different wavelengths for large and small molecules, implying differences in structures. MALDI mass spectra indicated molecules of mass of several thousand mass units with the upper limit of mass not defined. Planar Chromatography provides a fast, cheap method of isolating large molecular mass fractions of this biomass tar.
Teresa Kowalska - One of the best experts on this subject based on the ideXlab platform.
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The Role Seemingly of Amorphous Silica Gel Layers in Chiral Separations by Planar Chromatography
2020Co-Authors: Mieczysław Sajewicz, Teresa KowalskaAbstract:In Planar Chromatography, silica gel appears as the most frequently used adsorbent. Its preference as Planar chromatographic stationary phase is due to its high specific surface area (ca. 700 m 2 g -1 ) and relatively simple active sites (silanol groups, Si-OH). The high specific surface area of silica gel and a high density of coverage of its surface with the silanol active sites contribute jointly to an excellent separation performance of this adsorbent. In our experiments on chiral separation of the enantiomer pairs by Planar Chromatography, contradictory behavior of the silica gel layers versus the chiral compounds was observed. The migration tracks of chiral compounds in the ascending Planar chromatographic mode were not vertical but bent on either side being a function of analyte chirality. This deviation of the analyte' s migration track was noticed, when using the densitometric scanner to quantify the respective chromatograms. In order to confirm the hypothesis as to the microcrystalline nature of silica gel used in liquid Chromatography, it was further investigated through circular dichroism (CD) and the data thereof confirmed that the ' chromatographic' silica gels are not amorphous but microcrystalline, contributing to the (partial) horizontal enantioseparation of the antimer pairs. This paper summarizes the results of our investigation on the microcrystalline nature of silica gels used in Planar Chromatography and their impact on enantioseparation of the selected pairs of antimers.
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low temperature Planar Chromatography densitometry and gas Chromatography of essential oils from different sage salvia species
Journal of Liquid Chromatography & Related Technologies, 2010Co-Authors: Mieczyslaw Sajewicz, łukasz Wojtal, Dorota Staszek, Michal Hajnos, Monika Waksmundzkahajnos, Teresa KowalskaAbstract:Essential oils of plant origin are the multicomponent mixtures of mono-, di-, tri-, and sesquiterpenes. Due to their recognized curative, cosmetic, and nutritional properties on the one hand and an outstanding modern analytical potential on the other, qualitative and quantitative composition of essential oils currently is in the focus of interest for phytochemistry and pharmacognosy. Due to the recognized volatility of the essential oil components, in their case the analytical method of choice is gas Chromatography with mass spectrometric detection (GC-MS). However, great versatility of Planar Chromatography has resulted in a number of successful applications of this relatively simple and inexpensive separation technique to the investigations on composition of the volatile plant constituents as well. Generally, the low temperature preparative layer Chromatography (PLC) is used for preliminary fractionation of the essential oils, and the separated fractions are further analyzed by means of GC-MS. In this s...
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LOW TEMPERATURE Planar Chromatography–DENSITOMETRY AND GAS Chromatography OF ESSENTIAL OILS FROM DIFFERENT SAGE (SALVIA) SPECIES
Journal of Liquid Chromatography & Related Technologies, 2010Co-Authors: Mieczysław Sajewicz, łukasz Wojtal, Dorota Staszek, Michal Hajnos, Monika Waksmundzka-hajnos, Teresa KowalskaAbstract:Essential oils of plant origin are the multicomponent mixtures of mono-, di-, tri-, and sesquiterpenes. Due to their recognized curative, cosmetic, and nutritional properties on the one hand and an outstanding modern analytical potential on the other, qualitative and quantitative composition of essential oils currently is in the focus of interest for phytochemistry and pharmacognosy. Due to the recognized volatility of the essential oil components, in their case the analytical method of choice is gas Chromatography with mass spectrometric detection (GC-MS). However, great versatility of Planar Chromatography has resulted in a number of successful applications of this relatively simple and inexpensive separation technique to the investigations on composition of the volatile plant constituents as well. Generally, the low temperature preparative layer Chromatography (PLC) is used for preliminary fractionation of the essential oils, and the separated fractions are further analyzed by means of GC-MS. In this s...
Alan A. Herod - One of the best experts on this subject based on the ideXlab platform.
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comparison of the fractionation of a coal tar pitch by solvent solubility and by Planar Chromatography
Fuel, 1999Co-Authors: María J. Lázaro, Alan A. Herod, Rafael KandiyotiAbstract:Abstract Two methods of fractionation of a coal tar pitch, one based on solvent solubility separation and the other on preparative thin layer Chromatography were compared for effectiveness of the separation. The fractions were characterised using size exclusion Chromatography (SEC) and UV-fluorescence spectroscopy (UV-F). Fractionation by Planar Chromatography was found to give a better separation and to use less solvent than the solvent separation method. Both SEC and UV-F clearly showed less overlap in fractions separated by Planar Chromatography, compared to solvent fractionation. The cleaner separation of the heaviest fraction is particularly relevant for the mass spectroscopic investigation of large molecular mass materials, where the presence of lighter materials was observed to suppress high-mass signal. The close agreement observed between SEC and UV-F is consistent with previously reported correlations for coal tar pitches. However, the relevant SEC work was performed using pyridine as the mobile phase. We have found that 10%–15% of coal tar pitches cannot be dissolved in pyridine whilst total dissolution of coal tar pitch may be achieved using NMP. The calibration of analytical columns operated with NMP would be expected to lead to more accurate evaluations of molecular masses in these complex mixtures.
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fractionation of a wood tar pitch by Planar Chromatography for the characterisation of large molecular mass materials
Journal of Chromatography A, 1999Co-Authors: María J. Lázaro, Alan A. Herod, M Domin, Rafael KandiyotiAbstract:Abstract A commercial tar pitch derived from pine wood – Massen Pine (Pinus Massonia) and sold as Stockholm tar has been fractionated by Planar Chromatography with examination of the fractions by size exclusion Chromatography in NMP eluent, by UV-fluorescence and by matrix assisted laser desorption mass spectrometry. The relatively small molecules, mobile in Planar Chromatography, are shown to be non-polar. Large molecules were found in each fraction, corresponding in SEC elution times up to polystyrenes of molecular mass of at least 1.8 million. Size exclusion Chromatography profiles by UV light absorbance showed differences in relative absorbance of different wavelengths for large and small molecules, implying differences in structures. MALDI mass spectra indicated molecules of mass of several thousand mass units with the upper limit of mass not defined. Planar Chromatography provides a fast, cheap method of isolating large molecular mass fractions of this biomass tar.