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Near Infrared (NIR) Spectroscopy
and Calibration in
Biomass Characterisation
Paul Geladi, SBT,SLU
Content
• What is biomass?
• What is NIR spectroscopy?
• Instrument construction
• Examples
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Content
• What is biomass?
• What is NIR spectroscopy?
• Instrument construction
• Examples
Biomass
Non-food
Food & feed
Bioenergy
Pulp and paper
Forestry
Building materials
Textiles
Consumer products
Feed and safety
Arch
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Where is biomass found?
• Biotechnology
• Natural products
• Bioenergy
What is special about biomass?
• O-H
• C-H
• N-H
• C=O
• different atom sizes = good
• IR+NIR energy = movements of bonds
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O
H H
O
H H
O
H H
O
H H
Content
• What is biomass?
• What is NIR spectroscopy?
• Instrument construction
• Examples
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HCl molecule (no true sizes)
H Cl
UV,VIS Xray
UV,VIS
NIR,IR
Gamma ray
= electron
E
hn
Ground level
First excited level
Quantized energy levels
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E
hn
Ground level
First excited level
Emission
Thermal
E
hn
Ground level
First excited level
Emission
Thermal
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Near Infrared Spectra (NIR)
• 780-2500nm
• Suitable for all organic and bio materials
• Robust for industrial use
• Good penetration depth
• Many modes of measuring
• Powerful multivariate results
Cosmic Gamma Xray Ultraviolet Visible NIR Infrared Microwaves
Near Infrared Spectra
• Fast
• Simple sample preparation
• Nondestructive
• Online for process applications
• Need for calibration
• Opportunity for data analysis
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Near Infrared Spectra?
• Visible
• Infrared
• Raman
• Polarization
Visible Near infrared Infrared
Raman
400nm 780nm 2500nm 15000nm
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Content
• What is biomass?
• What is NIR spectroscopy?
• Instrument construction
• Examples
Transmission
Readout
electronics
Detector
Sample
cell
Mono-
chromator
Radiation
source
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Transmission
Readout
electronics
Detector
Sample
cell
Mono-
chromator
Radiation
source
I0 It
Reflection
Readout
electronics
Detector(s)
Sample
cell
Mono-
chromator
Radiation
source
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Reflection
Readout
electronics
Detector(s)
Sample
cell
Mono-
chromator
Radiation
source I0 Ir
EXAMPLE 1
• Organic synthesis
• Liquid
• Fiberoptic transflectance
• Over time
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Wavelength
”Absorbance” H2O
visible near infrared
Wavelength
Absorbance Organic synthesis over time
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CONCLUSION 1
• Possible to follow a reaction over time
• Identify reagents, products, intermediates
• Reaction kinetics
EXAMPLES 2
• Whole grain and flour
• Solid
• FT-NIR reflectance
• Genetic variation
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Wavelength
Pseudoabsorbance WHOLE GRAINS
CONCLUSION 2
• Grain and flour different
• Genetic information
• Location information
• Accurate protein content