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NMR Technology The analytical measurement principle Qualion NMR.

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Presentation on theme: "NMR Technology The analytical measurement principle Qualion NMR."— Presentation transcript:

1 NMR Technology The analytical measurement principle Qualion NMR

2 What is ¹H NMR? Hydrogen Nuclear Magnetic Resonance Provides picture of the hydrocarbon structure, from which we determine physical and chemical information Non invasive like MRI*, therefore all samples can be returned back to the process. Heavy opaque or dark materials easily analyzed Technology developed since 1950s MRI * Magnetic Resonance Imaging

3 What is ¹H NMR Analysis? NMR = Nuclear Magnetic Resonance Nuclear - NMR looks at the nuclei of molecules (protons-neutrons) More specifically at their nuclear spin Some nuclei have a magnetic moment due to that spin (behave like a small magnet) Most important, nuclei are 1 H, 13 C, 19 F and 31 P ¹H-NMR is looking at ¹H-protons in molecules, excellent for hydrocarbon analysis

4 The Electromagnetic Spectrum NMR spectroscopy uses radio-waves to interact with samples SPECTROSCOPY ANALYTICAL TECHNOLOGIES X-ray UV VIS IR Microwave ESR NMR

5 ¹H Proton – Magnetic Moment (M) M Hydrogen Atom (Proton) Proton is spinning + Magnetic moment (M) generated

6 Nuclear Spins and Magnetic Fields With no magnetic field, magnetic moments M are randomly oriented In a strong magnetic field (B o ), magnetic moments M align along B o M M M N S

7 Alignment and precessing of M Magnetic Moments Align and Precess at a Frequency w o w o is proportional to the Bo size e.g. Bo = 1.35 Tesla w o = 57 MHz N S Bo S WoWo

8 Bulk Magnetic Moment – M 0 Precessing spins can be described as a bulk magnetic moment Mo* *Mo = Summation of individual magnetic moments of all protons in the sample BoBo Mo N S

9 Re-align to a second magnetic axis Magnetic field B 1 causes M o to move and re-align to the second magnetic axis 57 MHz BoBo MoMo B1B1 N S RF pulse is turned on for 4-20 microseconds and generates a second magnetic field B 1

10 Re-align to original magnetic axis 57 MHz BoBo MoMo B1B1 N S When RF Pulse ends Relaxation of Mo generates an RF current that is picked by the irradiation coil : A decay signal is generated, called Free Induction Decay signal (FID) FID The protons relax and re-align to their original equilibrium position along Bo Axis

11 Measurement in a NMR Process analyser Top View Magnet Flow Pipe Probe

12 Multiple matched magnet segments. physically brought together to form condensed magnetic field of 1.35 Tesla NS Mechanical shims obtain rough B o homogeneity N S Electrical shim gradients N S Current passed through wire gradients creates shaped magnetic fields that are used to straighten field lines NMR permanent magnet technology

13 Fast Fourier Transform- FFT F.F.T. Free Induction Decay(FID) Time domain signal NMR Spectrum Frequency domain signal

14 Chemical Shift in NMR spectra How does the NMR resolve the different protons in the spectra ? Each proton in a different chemical environment (bond) senses a different magnetic field B X due to the shielding created by surrounding electrons More electrons = more shielding

15 Protons in different chemical environment Proton External applied field Bo S Actual field at protons N electron

16 Difference in sensed magnetic field Due to a difference in the sensed magnetic field, protons A and B precess at a different frequency W A and W B w A and w B are proportional to the size of B A and B B N S Bo S WAWA B BABA The precessing frequency becomes the fingerprint of the chemical environment of the different protons WBWB

17 From FID to results Fast Fourier transform Free Induction Decay(FID) Time domain signal NMR Spectrum Frequency domain signal Chemometric calibration models Results

18 Thank you! Contact us: QUALION NMR ANALYZERS Advanced Technology Center Building 22, P.O.B Haifa Israel Tel: (+972) Fax: (+972) Web:


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