Unlocking the Potential of NIR Spectroscopy

Introduction

Near-InfraRed (NIR) spectroscopy  is a remarkable tool that has improved our understanding of materials, opening new avenues for material analysis.

Material analysis is the process of characterizing material to understand its chemical composition, allowing us to classify it based on its properties(classification), qualify its suitability for specific applications(qualification), and/or quantify its compositional elements to ensure it meets the required standards and specifications (quantification).

Keep reading to learn more about NIR spectroscopy, its various applications, and how to choose the best NIR spectroscopy solution.

What is NIR spectroscopy?

NIR is the acronym for near-infrared spectroscopy, referring to the analytical technique that uses near-infrared light to scan and analyze material for compositional or characteristic traits. Each material has a unique interaction with infrared light, i.e., in NIR spectroscopy, we leverage this physical phenomenon by using light in the near-infrared spectrum to examine and analyze materials. Shining NIR light onto a sample and collecting the light reflected from or transmitted through it enables getting a wealth of information about the sample’s composition, structure, and properties without altering it(non-invasive). Thanks to decades of research, this analytical technique has been used in various industries due to its versatility and reliability in providing valuable insights.

Keep reading to know how it works.

How does NIR spectroscopy work?

Using NIR devices/ spectrometers, we capture and analyze the interaction between light and matter in the near-infrared range, light is composed of electromagnetic waves with different wavelengths; when NIR light interacts with a material, specific unique wavelengths are absorbed based on the material’s molecular composition.  (more on the different light responses and what they mean in this article)

By analyzing the response, NIR spectrometers provide information about the material’s composition and properties, such as moisture, starch, protein, fat, and oils, and quality is coded within the spectral response. For instance, the following figure shows the unique spectral response of a Dried Distillers Grain(DDG) sample. The x-axis of the diagram represents the wavelengths of the light that interacted with the sample. This y-axis represents how much light is absorbed by the sample. Information about this sample's water, protein, fat, and starch composition can be obtained at different wavelengths, as shown in the diagram.

To decode the spectral response, different mathematical modeling techniques, such as chemometrics, are used to create calibration models.

What are chemometrics?

In simple terms, chemometrics is a means to decode spectral responses to helpful information humans can understand. As defined by the International Chemometrics Society, “the discipline that uses mathematical and statistical methods to design optimal measurement procedures and experiments, and provide maximum chemical information by analyzing chemical data.

What are calibration models?

Calibration models are mathematical models that are trained with known values to predict the composition of new samples with unknown values.

As defined by ResearchGate, “finding a unique set of model parameters that provide a good description of the system behavior and can be achieved by confronting model predictions with actual measurements performed on the system.”

Read How NIR Works for a deeper dive into NIR spectroscopy and its advantages over other analytical techniques. 

The applications of NIR spectroscopy across industries

NIR Technology's versatility is evident in the vast array of applications it supports. It’s pivotal in optimizing crop health and yield in agriculture, ensuring the quality of pharmaceutical products, and maintaining the highest standards in various industrial processes. The following is an overview of use cases where NIR is used across various fields.

1. Animal nutrition  

NIR spectroscopy plays an important role in optimizing animal feed formulations. Helping farmers with rapid, precise data to achieve optimal feed mixes ensures that livestock receive the proper nutrients like poultry and aquaculture. This contributes to the efficient production of meat, milk, and eggs. Feed labs like Nutricontrol, Dairyland Labs, Rocker River Laboratories, and others also leverage NIR to analyze feed quality and composition accurately, guaranteeing safety and regulatory compliance.

Handheld spectroscopy devices like NeoSpectra can bring the power of NIR to cater to these needs and more. To do so, the devices need to be handy, easy to use, and provide lab-level accuracy. These devices can play a pivotal role in empowering field users with instant feed quality analysis to make informed decisions that directly impact the health and growth of livestock.

2. Medical cannabis

For the cannabis industry, NIR spectroscopy offers instant, non-destructive analysis of cannabis plants. Multiple stakeholders, such as breeders, growers, regulators, and labs, use NIR in different stages of the plant’s lifecycle to achieve various goals like selective breeding and development of varying cannabis strains or enhancing specific traits such as potency, flavor, aroma, and growth characteristics. As well as growing strains with different levels of cannabinoids and terpenes to cater to specific medical needs and many other practices.

For more, read this study about the use of NIR for the classification of medical cannabis.

3. Food

In the food industry, maintaining impeccable quality standards is non-negotiable. NIR spectroscopy ensures the quality of various food products like grains, seeds, dairy products, meat and poultry, oils, and fats. NIR enables businesses to uphold stringent quality standards across the value chain, ensuring that consumers receive food that is not only safe but also nutritious and delicious.

The food production industry is utilizing NIR to monitor production processes and ensure the consistency of a vast range of food products, as mentioned above, such as milk producers who use NIR to analyze milk composition for quality control before distribution or further processing, in addition to flour and milling operations that determine the quality of grains and the nutritional content of the flour, ensuring the highest standards for consumer products like bread and pasta.

4. Soil

NIR is successfully used in soil analysis to assess soil composition and health, allowing for the rapid determination of key soil attributes, such as soil carbon content, organic matter content, moisture levels, and nutrient availability, which are critical for optimizing crop management practices and enhancing agricultural productivity. With NIR spectroscopy, farmers gain valuable insights into soil conditions, enabling informed decisions that support sustainable farming and environmental stewardship.

Read more in this critical review of chemometric indicators commonly used for assessing the quality of the prediction of soil attributes by NIR spectroscopy

NIR was proven very effective in developing calibration models for soil properties like total carbon, nitrogen, and organic matter, refer to this study, which evaluates the effectiveness of visible and near-infrared (Vis-NIR) spectroscopy for soil analysis across different European farms. The study also highlights the importance of sample variation range in achieving accurate calibration.

5. Pharma

NIR devices were adopted by multinational companies in the late 1990s for raw material identification to reduce the cost of laboratory testing and ensure that all materials delivered are correctly labeled. NIR technology also offers 100% inspection with no need for sample dilution.

Some of NIR applications in pharma:

-      At-line testing

-      Blending operations

-      Physical parameters like particle size, hardness, compaction force, and dissolution rate

-      Moisture determination Content determination

NIR technology plays an important role in drug development and quality control in the pharmaceutical sector, operating as a vigilant detective for pharmaceutical companies as they utilize NIR spectrometers to assess the quality and composition of drug compounds, improving their drug development processes.

7. Polymers

NIR has greatly advanced polymer identification, characterization, and quantification. For instance, it's used for sorting polymers, quality control of raw materials, competitive analysis, and assessing thermal or photoinduced degradation in polymers and rubbers. This technique offers a blend of practicality and precision in polymer measurement and analysis.

Our dedicated blog on applications of NIR spectral sensing explores real-world examples showcasing its empowering impact on different industries and how NeoSpectra solutions drive progress and innovation in these sectors.

Note that various NIR applications come with multiple devices with different specifications. Keep reading to learn more about choosing the right one for you

Choosing the right NIR spectroscopy solution

Important considerations when selecting the NIR spectroscopy solution

1. Total cost of ownership
2. Parameters that need to be analyzed
3. Accuracy of results
4. Ease  of use
5. Model readiness and maintenance
6. Accessibility of instruments and results

Choosing the right tool requires careful assessment of the spectrometer's technical specifications (such as spectral range, resolution, and Signal Noise Ratio (SNR), ease of use, and compatibility with existing equipment. Additionally, considering your budget constraints and the NIR instrument provider's support is essential for making a well-informed decision.

We further discuss and explain those considerations in our blog: how to choose the right spectral sensing solution; read it for a thorough decision-making explanation.