Spectroscopy and Chemometrics News Weekly #48+49, 2016

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Near Infrared

Cannabis Analysis – On-Site Determination of Cannabis Strength using FT-IR Spectrosocopy FTNIR Ingredients LINK

Near Infrared NIRS, GC and HPLC Applications in Cannabis Testing THC CBD LINK

Raman

What happens when you use Raman spectroscopy to discriminate between brands of extra-virgin olive oil LINK

Raman spectroscopy of chocolate bloom LINK


Hyperspectral

Hyperspectral photoluminescence imaging of defects in solar cells | solar cells via LINK


Agriculture

Soy meal Protein bands LINK

Vitamin C distribution in acerola fruit by near infrared hyperspectral imaging HSI LINK


Equipment

Spectroscopists need freedom to analyse their spectral data, uncoupled from spectrometer hardware! LINK!


Chemometrics

Quality parameters in Castanhola fruit by NIRS to development of prediction models using PLS … in laboratory scale LINK

Monitoring Process-Water Quality Using NIRS and PLSR with Prediction Uncertainty Estimation LINK


Food & Feed

NIR diffuse reflection analysis of fruit – Food Science & Technology LINK


Agriculture

Innovation für die Obstwirtschaft: Neue Ansätze zur Messung und Vorhersage der Apfelqualität MONALISA LINK


Other

Hackers beware! Faking 3D-printed products just got harder. Full-spectrum spectroscopy for the win! LINK!

3D NDVI, using a low cost multi spectral camera. LINK

On the Generation of Random Multivariate Data | Multivariate Data LINK


CalibrationModel.com

Spectroscopy and Chemometrics News Weekly 46+47, 2016 | Spectroscopy NIRS Multivariate DataAnalysis Software LINK

Spektroskopie und Chemometrie Neuigkeiten Wöchentlich 46+47, 2016 | NIRS Spektroskopie Multivariate DatenAnalyse LINK

Spettroscopia e Chemiometria Weekly News 46+47, 2016 | NIRS Spettroscopia Chemiometria LINK


NIR Spectroscopy and Chemometric surveys, inquiry, polls and assessments (Part 3)


10. NIR in Supply Chain
Where in the supply chain are your NIR instruments located?

11. NIR Usage
How long has your company used NIR spectroscopy?

12. NIR instruments
How many NIR instrument units are in use in your company?

13. NIR Mobile
How much is the mobile hand-held percentage of total NIR devices in your company?

14. Calibration Source
How do you get the NIR Calibrations developed?

15. Calibration Training
How often do the operators get training about NIR Spectroscopy and Chemometrics?

16. NIR PreCalibrations
How many NIR Pre-Calibration, NIR factory calibrations or NIR starter calibrations have you in use?

17. Calibration Spectra
How many Spectra does your quantitative Calibration have in average?

Please vote and see the assessments below.

Part 1, Part 2
NIR in Supply Chain
Where in the supply chain are your NIR instruments located?
NIR Usage
How long has your company used NIR spectroscopy?
NIR instruments
How many NIR instrument units are in use in your company?
NIR Mobile
How much is the mobile hand-held percentage of total NIR devices in your company?
Calibration Source
How do you get the NIR Calibrations developed?
Calibration Training
How often do the operators get training about NIR Spectroscopy and Chemometrics?
NIR PreCalibrations
How many NIR Pre-Calibration, NIR factory calibrations or NIR starter calibrations have you in use?
Calibration Spectra
How many Spectra does your quantitative Calibration have in average?

Part 1, Part 2

NIR Spectroscopy and Chemometric surveys, polls and assessments (Part 2)


5. Calibration Precision
What do you believe, can NIR calibration models be more precise than reference values?

6. Calibration Maintenance
How often do you update your quantitative calibrations per year?

7. Quantitative Calibrations
How many quantitative (%) calibrations do you have in use?

8. Quantitative Parameters
In all your quantitative calibrations, how many parameters (properties) you have in total?

9. Qualitative Calibrations
How many qualitative (identification) calibrations do you have in use?

Please vote and see the assessments below.
Part 1, Part 3
Calibration Precision
What do you believe, can NIR calibration models be more accurate than reference method?
Calibration Maintenance
How often do you update your quantitative calibrations per year?
Quantitative Calibrations
How many quantitative (%) calibrations do you have in use?
Quantitative Parameters
In all your quantitative calibrations, how many parameters (properties) you have in total?
Qualitative Calibrations
How many qualitative (identification) calibrations do you have in use?

Part 1, Part 3

What is a NIR calibration used for?

NIR calibrations are used for NIR contents analysis as a productive analytical method. That is a two step procedure.
  1. A NIR analyzer does a non-destructive optical scan of a sample that yields a measured spectrum in seconds.
  2. A NIR calibration model can quantitatively predict (analyze, determine, estimate) multiple constituents, ingredients, contents, analytes, assay, API and other parameters and attributes (chemical, physical, biological, biochemical, sensory) summarized as properties, out of a single spectrum in milli seconds.
The NIR analysis is a very fast non-destructive analysis method that can replace or backup slower methods like wet chemical analysis, chemistry laboratory, sensory panels or rheology (viscosity). Or a NIR calibration can open the door to new possibilities of analytics, quality assurance and process control, by developing calibration models for parameters that seems to be impossible, because they are based on human knowledge, empirical values or sensory like taste value. If you have an NIR instrument, you can measure your samples systematically and thus develop your own calibration models.

What are pre-developed NIR pre-calibrations?

There are a lot of terms that means the same, pre-calibration or NIR starter calibration or pre-built calibration or pre-installed calibration orcalibration package or pre-developed calibrations or pre-calibrated NIR or global calibrations or nir global calibration package or factory calibrations or universal near-infrared (NIR) calibrations or local calibrations or ready-to-use NIR calibrations or off-the-shelf calibrations or factory-calibrated or pre calculated model or start-up calibrations or calibration equations or prefabricated nir calibrations or calibration library or mathematical model. That are Calibration models that are prepared and developed by a calibration specialist. They have collected a lot of samples over years and measured them with NIR and analyced it with reference methods. The NIR spectra are then calibrated against the reference values. This is called a NIR calibration or calibration model or sometimes calibration curve or calibration equation. Normally a precalibration is delivered as a file that is compatible to the used NIR analysis software. Such a calibration file does not contain the spectra nor the reference values.

So how can that work?

The only thing that is in the file is a description what it is for (e.g. protein in feed) and the chemometric model that is represented and stored as list of vectors and matrices. You can’t visualize them, it’s a black-box file. You have no insight of how the calibration is done, how are the settings, how is the prediction performance. You can not extend the calibration with your data to adjust it to your purpose or specialty. Most often the pre calibration files are protected, so you can use it only with a paid license to your software or even to your instrument serials number. These are some (not well known) limitations you will discover if you got one. But such starter calibrations are very useful to have a fast and easy start with a new NIR spectrometer. That’s the main reason why pre-calibrations are available. The second reason is that a collection of spectra can be reused to build such pre calibrations.

Predicting the future?

Are very old spectra useful to predict the future? To adjust a calibration model with newly collected data, the calibrations grows and contains more and more redundancy. That means there are very similar spectra with the same concentration range. So which spectra can be removed to make the calibration better? You maybe never ask this because often you hear, that the more spectra you put into a model the better it will be. Why to remove some spectra?
  • reduce not needed redundancy
  • makes the calibration smaller and less complex
  • makes the calibration better fit to the current situation of now and the near future
  • remove long past seasonal data if you have natural products because nature is changing
  • and of course bad outliers should be removed

Custom NIR calibrations

Build your own calibrations that perfectly fit to your specific sample matrix of your products and your preferred raw materials from your local suppliers. Nature grows differently depending on the geographical region, by seasons and year by year. As you know that NIR-Spectroscopy is not an absolute method, then you have to think about to calibrate these current changing effects into your models. If you own the spectra and the reference values then your are able to build your own calibration models and re-calibrate them when needed. So you have the full control on Calibration updates (also known as moving models).

Conclusion

A NIR-instrument can only measure NIR spectra. So the usefulness of NIR comes in with calibrations. That is very important to know when buying such an instrument. For a fast start you can use pre-built calibrations. Good reliably calibrations are offered from third party to quite high prices that level is similar to a cheaper NIR-Instrument! To continue successfully it is highly recommended to develop your own customized calibration (multivariate calibration model) with your own data from your own products, especially with the use of natural resources. Therefore you need knowledge about chemometrics and multivariate analysis (MVA), spectroscopy and the software used to get the calibration optimized. It is worthwhile to create your own calibrations, because you can calibrate product characteristics that are not covered by the proposed pre-calibrations.

What is NIR-Spectroscopy? (simple explanation, simply explained)

In the most cases a simple Halogen lamp emits light including the near infrared (NIR) spectrum (harmless radiation) to the sample/probe and the reflected light is measured. The light loses some energy on-and-in the sample depending on its physical and chemical (molecular) structure. The missing part of the light is treated as a fingerprint of the sample that is mathematically analyzed with prefabricated NIR calibration models (built with chemometric methods), based on trained known samples. That makes it possible to simultaneous analyze multiple physical- and chemical-properties (constituent, ingredient, analyte) within a few seconds and is non-destructive to samples.

The Ghost Calibrator

To explain our service in an other way, I use an analogy between a book and a calibration. Building good calibrations is like writing a good book (a bestseller). You can write in a foreign language (chemometrics) with a high sophisticated word-processor (the chemometric software) that has a grammar checker (an outlier detection). Due to the complexity of the language (chemometrics) and the difficulty of the chosen book topic (the data) and the incomplete automatic grammar checker, you can never be sure if the grammar is correct and may not lead to misunderstanding (bad prediction performance). So the best way is to let a native language speaker check and correct the text. In that way (the analogy), you can see us even as a ghostwriter (a ghost calibration developer, a ghostcalibrator) that helps you, writing the book (with long year experience, consolidated knowledge, time saving, a lot of benefit). The analogy fits very well, because you can define the topic of the book (with your data). Finally you own the calibration and you have the full insight in how it is done. You have it under full control.