Fourier transform NMR. Signal enhancement method. This is a mathematical operation in which the complex wave form can be broken down into simple mathematical operation. Analytical instrument in pharmaceutical analysis. Advanced version of NMR.

1. FOURIER- TRANSFORM
NMR SPECTROSCOPY
Presented by: ANUPAMA.CP
1sem M-Pharm
Pharmaceutical analysis
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2. FT-NMR
• It is the mathematical operation in which the complex
waveform can be broken-down into simple
mathematical operation.
• It is the mathematial operation required to convert a
time domain spectrum to frequency domain spectrum.
• Most important signal enhancement method use a
mathematical device called fourier transform.
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3. WORKING
1. In FTNMR spectroscopy the sample is given a
powerful pulse of radiofrequency radiation for a
short time 2-10 microseconds.
2. Due to the bombardment all the protons in the
ground state get excited by absorbing different
frequencies simultaneously at once.
3. Protons start relaxing at a time to give free induction
decay ( FID- time domain)
4. FID is the superimposed combination of all emitted
frequencies and is complex.
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4. 5. FID is converted into frequency domain by the use of
a mathematical process called fourier
transformation.
6. The frequency domain signal is very easy and helpful
for the sample study.
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5. FT-NMR INSTRUMENTATION
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6. • A radio transmitter coil that produces a short
powerful pulse of radio waves.
• A powerful magnet that produces strong magnetic
fields.
• The sample is placed in a glass tube that spins so the
test material is subject to uniform magnetic field.
• A radio receiver coil that detects radio frequencies
emitted as nuclei relax to a lower energy level.
• A computer that analyses and record the data.
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7. TIME AND FREQUENCY DOMAIN NMR SPECTRA
OF THE PROTONS IN PYRIDINE:
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8. ADVANTAGES OF FT-NMR
• FT-NMR is more sensitive and can measure weaker
signal.
• The pulsed FT-NMR is much faster.
• FT-NMR can be obtained with less than 0.5mg of the
compound. This is important in the biological
chemistry.
• The FT method also gives improved spectra for
sparingly soluble compounds.
• Suitable for the examination of nuclei that are
magnetic or very dilute samples.
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9. REFERENCES
1. Nuclear magnetic resonance spectroscopy by
D.A.R.Williams; wiley India pvt Ltd ; 2008;
page.no. 139-143.
2. Organic spectroscopy by William Kemp ; 3RD
edition ;ELBS; page.no.
3. Principles of instrumental analysis –
Dauglas.A.Skoog,5th edition; Eastern press
Banglore;1998;page.no. 558-563.
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