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The analytical measurement principle

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Presentation on theme: "The analytical measurement principle"— Presentation transcript:

1 The analytical measurement principle
Qualion NMR NMR Technology The analytical measurement principle

2 What is ¹H NMR? * Magnetic Resonance Imaging
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 1950’s 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 1H ,13C,19F and 31P ¹H-NMR is looking at ¹H-protons in molecules, excellent for hydrocarbon analysis

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

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

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

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

8 Bulk Magnetic Moment – M0
Precessing spins can be described as a bulk magnetic moment Mo* Bo N S Mo *Mo = Summation of individual magnetic moments of all protons in the sample

9 Re-align to a second magnetic axis
RF pulse is turned on for 4-20 microseconds and generates a second magnetic field B1 57 MHz Bo N S Mo B1 Magnetic field B1 causes Mo to move and re-align to the second magnetic axis

10 Re-align to original magnetic axis
The protons relax and re-align to their original equilibrium position along Bo Axis FID 57 MHz When RF Pulse ends Bo N S Mo B1 “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)

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

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

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

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 BX due to the shielding created by surrounding electrons More electrons = more shielding

15 Protons in different chemical environment
External applied field Bo Actual field at protons 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 WA and WB Bo BA N BB S S WB WA wA and wB are proportional to the size of BA and BB The precessing frequency becomes the fingerprint of the chemical environment of the different protons

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

18 Thank you! Contact us: QUALION NMR  ANALYZERS   Advanced Technology Center Building 22, P.O.B Haifa 31905 Israel    Tel:  (+972) Fax:  (+972)   Web: 

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