Category
- Spectroscopy and Spectrometry » NMR Spectroscopy
Booking Details
Facility Management Team and Location
Facility Features, Working Principle and Specifications
Features :
1)For solution-state NMR:5mm triple resonance H/C/N nuclei with 2H lock and 50G/cm gradient along Z axis.
2) For solid-state NMR:
3.2mm CP-MAS DVT triple resonance H/X/Y probe with max spinning speed of 24KHz
3.2mm CP-MAS triple resonance (H/C/N) E-free probe (Bio-solid) with max.spinning speed of 24KHz
1.9 mm H/C/N CP MAS triple resonance(H/C/N) probe with max. spinning speed of 42KHz
3)For wide-line static probes:
Low-temperature wide-line probe, solenoid coil
5mm and 7.5mm, can be tuned to various nuclei and can go upto 20K.
Working principle :
Nuclear Magnetic Resonance spectroscopy (NMR) is a one of the powerful and theoretically complex analytical technique. It is a spectroscopy where an ensemble of nuclei of atoms that possesses "magnetic moments" and "angular momentum" is subjected to an external magnetic field. As the nuclear angular momentum is quantized, these nuclei align either parallel or anti-parallel to the applied magnet field. Depending upon the nature of nuclei, one of these aligned states (in most cases, it is parallel) is more energetically favorable; that gives rise to net bulk magnetization. An external radiofrequency pulse is applied to the bulk magnetization to establish a resonance condition which in turn realigns bulk magnetization in the transverse plane of the external magnetic field. Ensemble of spins then precesses at a characteristic frequency and depending upon their chemical environment these precessional frequencies can be different for different chemical entity (Chmical shift). These ensemble of spin precessing in the magnetic field generates current which is a time decaying function as the spins restore their equilibrium states. Time domain signals are Fourier transformed to generate a frequency domain data which provide characteristic property of various chemical entities.
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Instructions for Registration, Sample Preparation, User Instructions, Precautionary Measures and Charges
External Users can come in-person or send your samples along with a letter from the Head / Guide on your College/Institute /Industry Original Letter Head for registration stating that the analysis is for research purpose to qualify for academic concession. The letter should be addressed to The Convener, HFNMR central facility, IIT, Bombay.
The analytical data / spectra are provided only for research / development purposes. These cannot be used as certificates in legal disputes.
Samples, letter and payment should be sent in the same cover only. If Samples are received without covering letter/DD, the samples will be sent back to the user without any further intimation/notice.
These cost does not include analysis charges.
Please send the samples in quantity as mentioned. Samples are not recovered, unless a special request is made.
Radioactive materials will not be entertained.
Unstable and explosive compounds are not accepted.
The payment should be made in advance by only Demand Draft (DD) in favour of: " The Registrar, IIT Bombay."
The DD along with sample and covering letter should be sent to the Convener, HFNMR facility,Room No. 304, SAIF
Data transfer and data processing : Data will be stored on the server and can be transferred to any computer in the campus using FTP.
Topspin will be accessible from any computer in the IITB campus.
For any query, please contact HFNMR Lab, 304, SAIF, IIT Bombay or ashutoshk@iitb.ac.in
- For Liquid-state: Instrument can probe 1H, 13C and 15N only.
- Users are advised to bring 15-20 mg of sample depending upon its molecular weight for obtaining high resolution proton or carbon NMR spectra.
- The sample should be completely soluble in 600 µl of the given solvent.
- For water-soluble samples, 10% D_2O must be added.
- For Bio-molecular samples (Protein, peptide and nucleic acids): concentration should be >500 µM.
- For multi-nuclei bio-molecular experiments: Samples must be isotope labeled.
- For solid-state: For MAS-NMR experiments, sample should be in the form of very fine powder (20 microns) and at least 40-60 mg of powder is required.
- Bio-solid samples can be in jelly form.
- For multi-nuclei bio-molecular experiments: Samples must be isotope labeled.
Instructions for users :
First time users should contact the operator to understand the requirements.
Sample should be completely soluble in 600 μl of the given solvent.
For low molecular weight (MW < 250) compounds a minimum of 1-3 mg and for high molecular weight 2-5 mg of samples should be provided for proton spectra.
For protein samples, concentration should be minimum 500 ïM for 2D and 3D experiments.
For solid state NMR sample requirement is ~ 100 mgs.
For proton decoupled Carbon-13 spectra, 50-100 mg of sample will be required
Solvent Requirement :For ensuring magnetic field stability and adjusting field homogeneity, a deuterium lock channel is provided. Therefore, samples are to be dissolved in a deuterated solvent. Deuterated solvents like D2O, CDCl3, are provided by the Facility free of cost. However Users have to pay for expensive solvents such as CD3COCD3, DMSOd6, C6D6, etc.. The User should check the solubility of the sample in any of these solvents (of course, in undeuterated solvent) and suggest best solvent.
Applications
Experiments can be performed with wide temperature range.
A series on nD experiments can be performed in the liquid phase.
Suitable for multi-nuclei, multi-dimensional MAS experiments.
Static solids can be investigated at various temperature (up to 20K).
Sample Details
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