1. A Very Brief Introduction to Infrared Spectroscopy
© ABB Group
April 29, 2019 | Slide 1

2. Basics of the Technique
© ABB Group
April 29, 2019 | Slide 2

3. Infrared Spectroscopy
The term “Infrared Spectroscopy” simply means the study matter using Infrared Radiation.
Matter is the “stuff” everything is made of. Matter is composed of molecules
Water Molecule
Infrared Radiation is composed of waves of light that are just beyond the range that is visible with our eyes.
© ABB Group
April 29, 2019 | Slide 3

4. Molecular Vibrations
The molecules that make up matter are vibrating all time. The bonds that hold the molecules together are stretching and bending thousands of times a second. For example the water molecules in the air in this room is vibrating right now.
Each type of molecule and type of vibration has a unique frequency. For example the frequency of the stretch vibration of a bond of Carbon and Oxygen like in Carbon Dioxide is stretching about 51,500000, times in each second.
© ABB Group
April 29, 2019 | Slide 4

5. Infrared Radiation
Light can also be measured in frequency ( just like with the number of vibrations in a second for molecular bonds) With frequencies of light we use the term wavenumber per centimeter this is the number of waves of the light that fit into each centimeter.
1cm
For example the frequency of this wave is 1cm-1
The infrared source in an infrared spectrometer creates infrared radiation of many different frequencies at the same time just like a light bulb creates many different frequencies of visible light.
© ABB Group
April 29, 2019 | Slide 5

6. Interaction of Light with Matter
If the frequency of the infrared light matches the frequency of the vibration in the bond of the molecule than the molecule absorbs some of the light.
Sample
Incident IR Beam
Remaining IR Beam
Infrared Source
Detector
© ABB Group
April 29, 2019 | Slide 6

7. Infrared Spectrum
Recording a spectrum is a little like tuning in to radio stations...
We scan through all the frequencies (like turning a tuning knob)
At certain frequencies the infrared light is absorbed by a molecular vibration (we hear music)
Sometimes the signal is strong, sometimes weaker (the peak is higher or lower)
Sometimes we hear nothing at all!
0.2
0.4
0.6
0.8
1.0
4000
3000
2000
1000
Absorbance spectrum of the sample
( polystyrene film )
Strength of signal
Scanning through frequencies
© ABB Group
April 29, 2019 | Slide 7

8. Interpreting Spectra
The position of the peak (frequency of absorption) tells us what type of molecular vibration we have and so can help to indentify what material we have
The size of the peak (the amount of light absorbed) tells us how many of those vibrations are there and so can tell us the concentration of a substance
Note: This spectra is shown as a transmittance rather than and absorbance spectra thus the peaks the opposite way up
© ABB Group
April 29, 2019 | Slide 8

9. Infrared spectroscopy – Mid or Near
Mid-infrared (FT-IR)
Strong absorption
Mainly used for qualitative analysis
Difficult to accurate control very small pathlengths
Classical laboratory technique
Direct chemical interpretation (band separation)
Simple calibrations (“peak height” models)
Difficult on process, cannot pass through glass and requires very small samples
Sensitive, can detect ppm levels
Near-infrared (FT-NIR)
Overtone and combination bands- Echoes of the MID IR bands
Weaker absorption
Not sensitive, concentrations need to be above 0.5%
Mainly C-H, O-H, N-H vibrations
Can be used for qualitative and quantitative analysis
Contains chemical and physical information
Well suited to process
No direct chemical interpretation
Calibrations requires “chemometrics” to help get the information out of the spectra
1st Overtone .. Combination.. Fundamental
NIR
Mid-IR
Frequency
Note: The same information is repeated in Mid-IR and NIR. In can be helpful to think of NIR spectra as the echo’s of the Mid IR spectrum

10. Calibration
© ABB Group
April 29, 2019 | Slide 10

11. Calibration Building a model Using a model
Infrared spectroscopy is generally not a primary technique of determination of physical and chemical properties.
The infrared Analyzer must be calibrated. We “train” the instrument using reference data from primary analytical method or using samples made from primary materials and methods.
Building a model
Using a model
Concentration, viscosity property data on each spectrum
Single sample infrared Spectra
Primary techniques use either primary standards or primary principles e.g.. titrations/ gravimetric methods)
Usually the customer provide the reference data and ABB performs and validates the calibration
Calibration Model
Calibration Model
Multiple infrared Spectra
Concentration, viscosity property prediction on the sample spectrum
© ABB Group
April 29, 2019 | Slide 11

12. Instruments
© ABB Group
April 29, 2019 | Slide 12

13. Lab - Platforms Platform MB-Series Wavelength Range (Mid or Near)
MB3600-HP10
MB3600-CH20
MB3600-CH40
MB000-PH
MB3000-CH60
MB3600-CH50
Industry or Application Specific Product
MB3600-CH30
MB3600-CH10
MB3600-PH
MB-RX
© ABB Group
April 29, 2019 | Slide 13

14. Process Platforms Remote, fibre optic systems – Highly Flexible
Extractive systems– Specialist applications
Platform
FTPA Series
FTPA Series
FTPA
TALYS
TALYS ASP310
TALYS ASP521
FTPA2000-HP20
FTPA2000-HP260
FTPA
FTPA
FTPA2000-HP460
FTPA2000-HP40
TALYS ASP501
TALYS ASP531
FTPA PH
FTPA2000-HP260X
FTPA T
FTPA T
FTPA2000-HP50
TALYS ASP511
TALYS ASP541
FTPA SC3
FTPA SC8
Industry or Application Specific Product
FTPA
FTPA2000-HP360
FTPA2000-PT260
FTPA T
FTPA2000-HP41
FTPA
FTPA2000-HP51
© ABB Group
April 29, 2019 | Slide 14

15. General Summary FTPA2000-260 MB3000 MB3600 TALYS Others
Fibre Optic process Near Infrared Analyser (Single or Multichannel)
Other specialist instruments usually for specific HPI applications
Mid Infrared Lab Analyser for Qualitative analysis
Near Infrared Lab Analyser for Quantitative analysis
© ABB Group
April 29, 2019 | Slide 15

16. Sampling Methods
© ABB Group
April 29, 2019 | Slide 16

17. Hardware Configuration
The hardware for an infrared application is composed of an instrument platform and a sampling accessory to introduce the sample to the instrument
Sample
Incident IR Beam
Remaining IR Beam
Infrared Source
Detector
Instrument
Sample Accessory
© ABB Group
April 29, 2019 | Slide 17

18. Laboratory- MB3000/MB3600 Sample Compartment
Infrared light passes from the source passes through the sample and is collected by the detector.
ABB offers a range of accessories that fit into the sample compartment depending on the nature of the sample
Source
Detector
© ABB Group
April 29, 2019 | Slide 18

19. Process - Fibre Optic Remote Spectrometers
Infrared light output through fibre optics
Source
Sample Compartment
Detector
Infrared light returned through fibre optics
Infrared light passes from the source through a glass fibre to the sampling accessory. Once interacted with the sample the remaining light is passed back though another fibre back to the instrument detector.
NIR only as Mid IR will not pass through the glass fiber
© ABB Group
April 29, 2019 | Slide 19

20. Transmission
In a transmission measurement the sample is simply placed directly into the infrared beam between the source and detector.
Transmission measurement can be carried out on solids, liquids and gases.
Sample
Incident IR Beam
Remaining IR Beam
Infrared Source
Detector
Sample “Pathlength”, this is the thickness of the sample measured. The greater (the thicker the sample) the pathlength the more infrared radiation is absorbed. So different measurements will need different pathlengths. As Mid-IR has stronger absorption the pathlengths need to be more smaller or all the radiation will be absorbed and none will reach the detector
© ABB Group
April 29, 2019 | Slide 20

21. Transmission – Example Accessories
Vial Holder - Lab
Accommodates 3 vial diameters for 3 mm, 5 mm and 10 mm pathlengths.
NIR only
Liquid Cell - Lab
Two windows with a controlled sample gap.
Pathlengths from a few microns (Mid IR) to several mm (NIR)
NIR and MIR
Flow Cell - Process
Path lengths from 1mm to 10mm
Wide range or pipe interface diameters and materials
NIR only
© ABB Group
April 29, 2019 | Slide 21
© ABB Group
April 29, 2019 | Slide 21

22. Diffuse Reflectance Infrared Source Detector Remaining IR Beam
Diffuse reflectance allows for the measurement of a wide range of solid samples such as surface coatings, powders, paint chips etc. The incident bema is directed at the sample and a portion of the reflected light is measured by the detector. Can be used in the Mid and NIR but mainly used in the NIR.
© ABB Group
April 29, 2019 | Slide 22

23. Diffuse Reflectance – Example Accessories
Powdir Samplir- Lab
Measures the sample held in a glass vial
Can rotate to better average the sample
NIR only
Diffuse Reflectance Probe- Lab or Process
Various versions available for use with laboratory or process instruments
NIR only
© ABB Group
April 29, 2019 | Slide 23

24. Attenuated Total Reflection (ATR)
The infrared beam is reflected inside a reflecting crystal of high refractive index
When it hits the crystal-air interface the infrared radiation extend fractionally outside of the crystal
The sample in contact with the crystal will then absorb some radiation as it would with other methods and the remaining portion of the light is directed to the sample
The ATR accessory can use a single reflection or many (e.g. 10) the more reflections the greater the pathlength through the sample
Difficult to accurately reproduce the pathlength so ATR is mainly for qualitative analysis (identification).
ATR Crystal
Infrared Source

25. ATR – Examples Miracle Single Bounce ATR – Lab
Can be used for all types of solids and liquids
Usually a Diamond or ZnSe
Clamp used for solids to get good contact with ATR
Mid-IR only
ATR Probes – Lab and Pilot Plant
To be used with liquids
Usually a Diamond or ZnSe
Come with special mid-IR fibres (only for use over short distances)
Mid-IR only
© ABB Group
April 29, 2019 | Slide 25

26. Software
© ABB Group
April 29, 2019 | Slide 26

27. Software Horizon QA Horizon MB FTSW100 Laboratory Process
Workflow software. Controls the analyser settings and holds a configuration to allow rapid acquisition of results by an operator though simple onscreen prompts. Manages historical data and generate reports.
Spectral viewing and interrogation software. Has multiple optional modules to add extra functionality. E.g “Quantify module” for building calibration models.
Aimed more at the skilled user.
A ground up dedicated process control software. For a Near Infrared instrument. Manages all aspects of data acquisition, data handling, I/Os, DCS integration, alarms, reporting and analyser diagnostics.
© ABB Group
April 29, 2019 | Slide 27