Both Clemens Anklin and Nikolaus Nestle gave you good advise. Note also that chloroform is an "acidic" solvent which at higher temperatures can react with some compounds (e.g., some amides, amines, etc.). Solvents, like DMSO, can start "smoking" below their boiling points. If you cannot dissolve your material in a suitable NMR solvent, you can still obtain usable spectra using Dr. Anklin's suggested method of preparation, especially if you can safely heat the "neat" sample. I have obtained many spectra on such "neat" samples, [mostly polymers (1H, 13C, as well as 19F), at higher temperatures], over the years. Best of luck in your research! AF
Both Clemens Anklin and Nikolaus Nestle gave you good advise. Note also that chloroform is an "acidic" solvent which at higher temperatures can react with some compounds (e.g., some amides, amines, etc.). Solvents, like DMSO, can start "smoking" below their boiling points. If you cannot dissolve your material in a suitable NMR solvent, you can still obtain usable spectra using Dr. Anklin's suggested method of preparation, especially if you can safely heat the "neat" sample. I have obtained many spectra on such "neat" samples, [mostly polymers (1H, 13C, as well as 19F), at higher temperatures], over the years. Best of luck in your research! AF
Very viscous materials are difficult to get into tubes. 10mm tubes are easier than 5mm tubes. An easy way to get the material to the bottom of the tube is by centrifugation. Use a centrifuge that can hold 15 ml Falcon vials. Put you NMR tube in a falcon and put two of these sets in your centrifuge. Spin until all the material is down in the tube and free of bubbles. The more homogeneous the sample is the better spectra you get. If possible run at higher temperatures to bring viscosity down. More liquid samples will give sharper lines.
Very viscous materials are difficult to get into tubes. 10mm tubes are easier than 5mm tubes. An easy way to get the material to the bottom of the tube is by centrifugation. Use a centrifuge that can hold 15 ml Falcon vials. Put you NMR tube in a falcon and put two of these sets in your centrifuge. Spin until all the material is down in the tube and free of bubbles. The more homogeneous the sample is the better spectra you get. If possible run at higher temperatures to bring viscosity down. More liquid samples will give sharper lines.
If it is not possible to reduce the viscosity of the sample enough, then you could also try HR-MAS (high resolution magic angle spinning). I have found this very good on semi-solids (such as molecules tethered to solvent-swollen polystyrene beads). Of course, first you need to find someone who has such an NMR probe!
If it is not possible to reduce the viscosity of the sample enough, then you could also try HR-MAS (high resolution magic angle spinning). I have found this very good on semi-solids (such as molecules tethered to solvent-swollen polystyrene beads). Of course, first you need to find someone who has such an NMR probe!
No additional/special preparation is required for NMR. You have to check the solubility of your compound (You can try Chloroform and DMSO as these are most commonly used solvents in NMR). Then, You can take Proton as well as Carbon NMR spectra. Good Luck.
No additional/special preparation is required for NMR. You have to check the solubility of your compound (You can try Chloroform and DMSO as these are most commonly used solvents in NMR). Then, You can take Proton as well as Carbon NMR spectra. Good Luck.
Clemens is right: getting viscous stuff into tubes is challenging. However, as Avtar already mentioned, you should dissolve your stuff anyhow and then most likely the solution will have a much lower viscosity. If the stuff still comes with broad lines in the spectrum, heating the sample up will be a good next step. However, be aware that solvents like Chloroform will evaporate very rapidly at elevated temperature. DMSO is better as it has a higher boiling point. And last but not least: whatever solvent you may use, get a deuterated one from your NMR colleague. Good luck!
Clemens is right: getting viscous stuff into tubes is challenging. However, as Avtar already mentioned, you should dissolve your stuff anyhow and then most likely the solution will have a much lower viscosity. If the stuff still comes with broad lines in the spectrum, heating the sample up will be a good next step. However, be aware that solvents like Chloroform will evaporate very rapidly at elevated temperature. DMSO is better as it has a higher boiling point. And last but not least: whatever solvent you may use, get a deuterated one from your NMR colleague. Good luck!
Feasibility of 1H-High Resolution-Magic Angle Spinning NMR Spectroscopy in the Analysis of Viscous Cosmetic and Pharmaceutical Formulations Mattia Marzorati, Peter Bigler, Michel Plattner, and Martina Vermathen Analytical Chemistry 201385 (8), 3822-3827 DOI: 10.1021/ac400559z
Feasibility of 1H-High Resolution-Magic Angle Spinning NMR Spectroscopy in the Analysis of Viscous Cosmetic and Pharmaceutical Formulations Mattia Marzorati, Peter Bigler, Michel Plattner, and Martina Vermathen Analytical Chemistry 201385 (8), 3822-3827 DOI: 10.1021/ac400559z
Hi, is there literature that details any of the above recommendations? I am also working with very viscous samples and would like to use the above recommendations but also reference them in my report. Please assist in this regard. Thank you
Hi, is there literature that details any of the above recommendations? I am also working with very viscous samples and would like to use the above recommendations but also reference them in my report. Please assist in this regard. Thank you
Very viscous materials are difficult to get into tubes. 10mm tubes are easier than 5mm tubes. An easy way to get the material to the bottom of the tube is by centrifugation. Use a centrifuge that can hold 15 ml Falcon vials. Put you NMR tube in a falcon and put two of these sets in your centrifuge. Spin until all the material is down in the tube and free of bubbles. The more homogeneous the sample is the better spectra you get. If possible run at higher temperatures to bring viscosity down. More liquid samples will give sharper lines.
Very viscous materials are difficult to get into tubes. 10mm tubes are easier than 5mm tubes. An easy way to get the material to the bottom of the tube is by centrifugation. Use a centrifuge that can hold 15 ml Falcon vials. Put you NMR tube in a falcon and put two of these sets in your centrifuge. Spin until all the material is down in the tube and free of bubbles. The more homogeneous the sample is the better spectra you get. If possible run at higher temperatures to bring viscosity down. More liquid samples will give sharper lines.
Both Clemens Anklin and Nikolaus Nestle gave you good advise. Note also that chloroform is an "acidic" solvent which at higher temperatures can react with some compounds (e.g., some amides, amines, etc.). Solvents, like DMSO, can start "smoking" below their boiling points. If you cannot dissolve your material in a suitable NMR solvent, you can still obtain usable spectra using Dr. Anklin's suggested method of preparation, especially if you can safely heat the "neat" sample. I have obtained many spectra on such "neat" samples, [mostly polymers (1H, 13C, as well as 19F), at higher temperatures], over the years. Best of luck in your research! AF
Both Clemens Anklin and Nikolaus Nestle gave you good advise. Note also that chloroform is an "acidic" solvent which at higher temperatures can react with some compounds (e.g., some amides, amines, etc.). Solvents, like DMSO, can start "smoking" below their boiling points. If you cannot dissolve your material in a suitable NMR solvent, you can still obtain usable spectra using Dr. Anklin's suggested method of preparation, especially if you can safely heat the "neat" sample. I have obtained many spectra on such "neat" samples, [mostly polymers (1H, 13C, as well as 19F), at higher temperatures], over the years. Best of luck in your research! AF
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Very viscous materials are difficult to get into tubes. 10mm tubes are easier than 5mm tubes. An easy way to get the material to the bottom of the tube is by centrifugation. Use a centrifuge that can hold 15 ml Falcon vials. Put you NMR tube in a falcon and put two of these sets in your centrifuge. Spin until all the material is down in the tube and free of bubbles. The more homogeneous the sample is the better spectra you get. If possible run at higher temperatures to bring viscosity down. More liquid samples will give sharper lines.
Very viscous materials are difficult to get into tubes. 10mm tubes are easier than 5mm tubes. An easy way to get the material to the bottom of the tube is by centrifugation. Use a centrifuge that can hold 15 ml Falcon vials. Put you NMR tube in a falcon and put two of these sets in your centrifuge. Spin until all the material is down in the tube and free of bubbles. The more homogeneous the sample is the better spectra you get. If possible run at higher temperatures to bring viscosity down. More liquid samples will give sharper lines.
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VOTE
If it is not possible to reduce the viscosity of the sample enough, then you could also try HR-MAS (high resolution magic angle spinning). I have found this very good on semi-solids (such as molecules tethered to solvent-swollen polystyrene beads). Of course, first you need to find someone who has such an NMR probe!
If it is not possible to reduce the viscosity of the sample enough, then you could also try HR-MAS (high resolution magic angle spinning). I have found this very good on semi-solids (such as molecules tethered to solvent-swollen polystyrene beads). Of course, first you need to find someone who has such an NMR probe!
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Thank you John, highly appreciated.
Thank you John, highly appreciated.
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No additional/special preparation is required for NMR. You have to check the solubility of your compound (You can try Chloroform and DMSO as these are most commonly used solvents in NMR). Then, You can take Proton as well as Carbon NMR spectra. Good Luck.
No additional/special preparation is required for NMR. You have to check the solubility of your compound (You can try Chloroform and DMSO as these are most commonly used solvents in NMR). Then, You can take Proton as well as Carbon NMR spectra. Good Luck.
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VOTE
Clemens is right: getting viscous stuff into tubes is challenging. However, as Avtar already mentioned, you should dissolve your stuff anyhow and then most likely the solution will have a much lower viscosity. If the stuff still comes with broad lines in the spectrum, heating the sample up will be a good next step. However, be aware that solvents like Chloroform will evaporate very rapidly at elevated temperature. DMSO is better as it has a higher boiling point. And last but not least: whatever solvent you may use, get a deuterated one from your NMR colleague. Good luck!
Clemens is right: getting viscous stuff into tubes is challenging. However, as Avtar already mentioned, you should dissolve your stuff anyhow and then most likely the solution will have a much lower viscosity. If the stuff still comes with broad lines in the spectrum, heating the sample up will be a good next step. However, be aware that solvents like Chloroform will evaporate very rapidly at elevated temperature. DMSO is better as it has a higher boiling point. And last but not least: whatever solvent you may use, get a deuterated one from your NMR colleague. Good luck!
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thank you everyone for answering! i really appreciate all the helpful information!
thank you everyone for answering! i really appreciate all the helpful information!
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VOTE
Feasibility of 1H-High Resolution-Magic Angle Spinning NMR Spectroscopy in the Analysis of Viscous Cosmetic and Pharmaceutical Formulations
Mattia Marzorati, Peter Bigler, Michel Plattner, and Martina Vermathen
Analytical Chemistry 2013 85 (8), 3822-3827
DOI: 10.1021/ac400559z
Feasibility of 1H-High Resolution-Magic Angle Spinning NMR Spectroscopy in the Analysis of Viscous Cosmetic and Pharmaceutical Formulations
Mattia Marzorati, Peter Bigler, Michel Plattner, and Martina Vermathen
Analytical Chemistry 2013 85 (8), 3822-3827
DOI: 10.1021/ac400559z
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Hi, is there literature that details any of the above recommendations? I am also working with very viscous samples and would like to use the above recommendations but also reference them in my report. Please assist in this regard.
Thank you
Hi, is there literature that details any of the above recommendations? I am also working with very viscous samples and would like to use the above recommendations but also reference them in my report. Please assist in this regard.
Thank you
More
VOTE
Very viscous materials are difficult to get into tubes. 10mm tubes are easier than 5mm tubes. An easy way to get the material to the bottom of the tube is by centrifugation. Use a centrifuge that can hold 15 ml Falcon vials. Put you NMR tube in a falcon and put two of these sets in your centrifuge. Spin until all the material is down in the tube and free of bubbles. The more homogeneous the sample is the better spectra you get. If possible run at higher temperatures to bring viscosity down. More liquid samples will give sharper lines.
Very viscous materials are difficult to get into tubes. 10mm tubes are easier than 5mm tubes. An easy way to get the material to the bottom of the tube is by centrifugation. Use a centrifuge that can hold 15 ml Falcon vials. Put you NMR tube in a falcon and put two of these sets in your centrifuge. Spin until all the material is down in the tube and free of bubbles. The more homogeneous the sample is the better spectra you get. If possible run at higher temperatures to bring viscosity down. More liquid samples will give sharper lines.
More
VOTE