SAIF at the Indian Institute of Technology, Madras is equipped with sophisticated instruments to carry out spectral measurements, structure determination and chemical analysis on par with advanced countries. Click on the instrument name in the following table for more information on the type/model available.
List of Instruments
Instrument Purpose Limitations
Vibrating Sample Magnetometer(VSM) The magnetic moment measurements of compounds are made with this machine. This is a nondestructive technique. The magnetic susceptibility value is helpful in the determination of the oxidation state of paramagnetic ions. Liquid samples cannot be analysed.
500 MHz FT NMR Spectrometer FT-NMR spectroscopy is used to determine the molecular structure based on the chemical environment of the magnetic nuclei like 1H, 13C, 31P, etc., even at low concentrations. This is one of the most powerful nondestructive techniques in elucidating the molecular structure of biological and chemical compounds Only Samples very highly soluble in organic solvents can be used for NMR measurements. Paramagnetic compounds generally will give broad lines and may not give any useful data. SAIF IIT/M does not have facility to measure NMR of solids (CP/MAS)
FT IR Spectrophotometer The infrared spectrum originates from the vibrational motion of the molecule. The vibrational frequencies are a kind of fingerprint of the compounds. This property is used for characterization of organic, inorganic and biological compounds. The band intensities are proportional to the concentration of the compound and hence qualitative estimations are possible. Generally organic compounds and many inorganic compounds give useful results. Heavy metal compounds some times absorb at lower wave-number (low energy) region only, which may not be covered by the instrument we have.
FT-Raman Spectrometer Raman spectroscopy results from inelastic scattering (Raman scattering) of radiation from molecules. The difference in frequencies of the incident and scattered light corresponds to the vibrational and rotational energies of the molecule. It is the change in the polarisability of the molecule that is responsible for the transitions. Symmetry selection rules predict that for centro-symmetric molecules, the Raman active vibrations will be IR inactive and vice versa. (mutual exclusion principle). Fluorescent materials do not give any useful result.
Spectro Fluorimeter Fluorescence has proven to be a versatile tool for a myriad of applications. It's a powerful technique for studying molecular interactions in analytical chemistry, biochemistry, cell biology, physiology, nephrology, cardiology, photochemistry, and environmental science. It boasts phenomenal sensitivity for the analytical chemist or the life scientist working at nanomolar concentrations. But fluorescence offers much more than mere signal-gathering capability. The sample should be fluorescing, preferably with a fluorescence quantum yield >0.10. the substrate should be completely soluble in the choice of solvent given. absorption and emission wavelengths should be specified. compound should be photo-stable. minimum sample required is 25 to 50 mg. measurements can also be carried out in solid thin film.
Life time measurement system Lifetime fluorescence spectroscopy investigates the change in fluorescence over time of a sample when irradiated with UV, visible, or near-IR light. This decay in fluorescence can be measured over a wide time range: from picoseconds to milliseconds and beyond. The sample should be fluorescing, preferably with a fluorescence quantum yield > 0.10. The substrate should be completely soluble in the choice of solvent given. Absorption and emission wavelengths should be specified. Compound should be photo-stable. Minimum sample required is 25 to 50 mg. Measurements can also be carried out in solid thin film.
Differential Scanning Calorimetry (DSC) Thermal analysis is a group of techniques in which the physical property of a substance is measured as a function of temperature, while the substance is subjected to a controlled temperature program. These include change in weight [(Thermogravimetry (TG)], temperature difference [(Differential Thermal Analysis (DTA)] and heat flux difference [(Differential Scanning Calorimetry (DSC)]. Only DSC facility is at present available at SAIF IIT/M Samples should not be toxic, corrosive or explosive. Do not submit samples which will react with Aluminium constantan. The heat-flux sensor is made up of an alloy of constantan. Samples which produce high vapor pressure on heating cannot be analysed.
GC-MS Spectrometer Mass spectrometry has become a vital tool in the hands of organic chemists and biochemists because of its potential to supply definitive, qualitative and quantitative information on molecules based on their structural compositions. Gas chromatography attached to a Mass spectrometer (GC-MS) enables mixture of small molecules to be separated and analyzed. Only organic compounds of low molecular weight (< 600) can be analyzed. Metal ions shall not be present. For GC-MS the columns available are limited.
SingleCrystal X-RayDiffractometers The molecular structure, atomic coordinates, bond lengths, bond angles, molecular orientation and packing of molecules in single crystals can be determined by X-ray crystallography. Single crystal X-ray diffractometer collects intensity data required for structure determination. SAIF IIT/ has two Single crystal XRD instruments. Only Single crystals can be analysed. Non-crystalline samples (amorphous) sample cannot be analysed. The size of the crystal should be of the order of a few mm3
Inductivelycoupled plasmaoptical emissionspectrometer (ICP OES) Emission spectrometry is based on the principle that atoms or irons in an excited state tend, to revert back to the ground state and in so doing emit characteristic wavelength and intensity of that light is proportional to the concentration of that particular element in the sample solution. This technique is used for quantitative and quality determination of the metals and metalloids in the following sample. Samples should be submitted in clear aqueous form. Solids, suspensions, highly viscous, highly acidic, highly alkaline and organic solutions cannot be analysed as such. A minimum final volume of 25 ml of the sample solution is required for analysis.
Scanning Electron Microscope SEM gives high resolution surface morphological images, and also has the analytical capabilities such as detecting the presence of elements down to boron (B) on any solid conducting materials through the energy dispersive X-ray spectrometry (EDX) providing crystalline information from the few nano meter depth of the material surface via electron back scattered detection (BSD) system attached with microscope and advanced technological PBS (WDS) for elemental analysis. Liquid samples and solid samples which are magnetic/ferrite cannot be measured.

  Home |  Objectives |  Administration |  Facilities |  Charges list |  Personnel |  Application Form |  Alumni |  Contact us  
    powered by Jeeva A © 2009 All Rights Reserved, SAIF IITM