Date post: | 11-May-2015 |
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Prepared by Lawrence Kok
Video Tutorial on Atomic Absorption /Emission Spectroscopy, Nuclear Magnetic Resonance Spectroscopy.
Clear explanation on how AAS works Short demo on flame chamber
Video on Atomic Absorption Spectroscopy
Detail explanation on how AAS works
Video on how MRI body imaging works
Video on MRI in detail Video on MRI simplified
Video tutorial on chemical shift Spin spin coupling for HNMR
Video on flame test Video on emission spectrum explained
How Atomic Emission spectroscopy works
Atomic Emission Spectroscopy vs Atomic Absorption Spectroscopy
Ground state
Excited state
Atomic Absorption Spectroscopy
Uses of AAS
Samples metals ions found
Uses of AAS and Part of AAS
Parts of Atomic Absorption Spectroscopy1
Parts of Atomic Absorption Spectroscopy• Light Source• Fuel Atomiser• Monochromator• Detector
Parts of Atomic Absorption Spectroscopy1
2
Parts of Atomic Absorption Spectroscopy• Light Source• Fuel Atomiser• Monochromator• Detector
Parts of Atomic Absorption Spectroscopy
Parts of AAS
1
2
3
Parts of Atomic Absorption Spectroscopy• Light Source• Fuel Atomiser• Monochromator• Detector
Atoms of a particular element (Pb) absorb light exactly the same frequency emitted by the lamp
How Atomic Absorption Spectroscopy Works ?
How to determine Pb2+ ion in a sample ?
Atoms of a particular element (Pb) absorb light exactly the same frequency emitted by the lamp
How Atomic Absorption Spectroscopy Works ?
Pb determination in a sample
How to determine Pb2+ ion in a sample ?1
2
100dm3 of contaminated water was reduced by boiling to 7.50dm3. The reduced volume was tested, it had absorbance of 0.55. Calculate the conc Pb2+ ions (mg/dm3) in original sample.
Ans: Conc of Pb2+ from graph (interpolation) – 1.15mgdm3
100dm3
7.50dm3
Volume reduced by
Vol = 100dm3M = ?
Vol = 7.50dm3M = 1.15mgdm3
Amt moles before = Amt moles after M x V = M X V M x 100 = 1.15 x 7.50 M = (1.15 x 7.50)/ 100 = 8.63 x 10-2 mgdm3
3
Question
Answer
Clear explanation on how AAS works Short demo on flame chamber
Video on Atomic Absorption Spectroscopy
Detail explanation on how AAS works
Nuclear Magnetic Resonance Spectroscopy
In the absence of External Magnetic Field (EMF)
Nuclear Magnetic Resonance Spectroscopy1
2
Nuclear Magnetic Resonance Spectroscopy
3In the presence of External Magnetic Field (EMF)
Split into TWO different level
Nuclear Magnetic Resonance Spectroscopy
3In the presence of External Magnetic Field (EMF)
Split into TWO different level
4Absorb radiofrequency to move to higher energy state
Nuclear Magnetic Resonance Spectroscopy
How to interpret NMR spectra ?
Nuclear Magnetic Resonance Spectroscopy
Chemical shift for CH3CH2OH 1
Nuclear Magnetic Resonance Spectroscopy
Chemical shift for CH3CH2OH and TMS (STD) 1
2 TMS as internal reference/STD
Hydrogen is deshielded as electronsare withdrawn away from H by CO group
Hydrogen is shielded by electrons donated to H by CH2 group
Chemical Shift (Shielding and Deshielding Effect)1
2
3
Hydrogen deshielded Hydrogen shielded
Placed in external magnetic field Placed in external magnetic field
4
Absorb higher radiofrequency – appears downfield Absorb lower radiofrequency – appears upfield
Chemical shift of various electron withdrawing groups
Video on how MRI body imaging works
Video on MRI in detail Video on MRI simplified
Video tutorial on chemical shift Spin spin coupling for HNMR
Click here to NMR spectra library for various organic compounds
Uses of HNMR1. Structural Determination of Organic compound
2. Medical uses in body scanner using Magnetic Resonance Imaging• Body placed inside a magnetic field (MRI) and 3D image of various organs produced• Protons found inside our body tissues – water, lipids, proteins, carbohydrates
different water/lipid ratios in different tissues
absorb harmless radiofrequency
different NMR signals due to different proton environment
different image will be produced
Acknowledgements
Thanks to source of pictures and video used in this presentation
Thanks to Creative Commons for excellent contribution on licenseshttp://creativecommons.org/licenses/
Prepared by Lawrence Kok
Check out more video tutorials from my site and hope you enjoy this tutorialhttp://lawrencekok.blogspot.com