Advantages and applications of NIR spectroscopy
In excerpts from our its Applied Spectral Knowledge podcast (anchor.fm/ocean-insight), Ocean Insight experts weigh in on NIR spectroscopy.
Featured are Yvette Mattley, lab services manager; Ty Olmstead, VP, engineering and product management; and Joe Bonvallet, senior application scientist
What are the advantages of NIR spectroscopy?
Mattley: There's a lot of useful information in the NIR and Shortwave NIR (SWIR) ranges about the composition of chemicals, soil samples and features that you can't really see in the visible spectral range. If you're involved in chemical identification, plastics identification, soil classification or vegetation analysis, you really want to be at wavelengths greater than 800 nm.
Bonvallet: Another big advantage with NIR is the depth of sample penetration that you have compared with the visible region. If you're trying to probe into a surface or into the structure of a compound or material, NIR is a great technique.
Mattley: Also, there's very little sample preparation to be done. Many different sampling options are available, including flow cells and cuvette holders. NIR is very flexible that way.
Which applications are best for NIR Spectroscopy?
Olmstead: The biggest success I've seen is in food processing and identifying the quality of food. The penetration depth for samples can be on the order of a couple of millimeters into the products, so we’re able to see blemishes or get information below the surface of the food that we're looking at. We've been very successful at Ocean Insight in predicting tomatoes’ life spans from the harvester to within about a day of when decay will form on the tomato. This is powerful stuff that can help food quality across the world, getting good food to people and sorting through produce based on different conditions.
Mattley: NIR spectroscopy is an effective, non-destructive way to determine the sweetness or ripeness of a product without having to cut it open and destroy it in the process.
Bonvallet: There’s also some interesting stuff with biological applications. I was at a customer site where they're looking at different proteins in the drug discovery process and looking in the 4000-6000 wavenumber range, looking at some aliphatics and aromatic rings out there for the identification of a compound that could be harmful in a drug. When you make these drugs, they're stored in different containers and sometimes those containers will shed a layer. And that's where you get these aromatic rings in your solution. This company is looking at quantifying that and seeing if it's harmful to the body.
Olmstead: Also, NIR can be a useful tool for industrial applications where you're looking at dissolved chemicals in aqueous solutions or even in solvents. The nice thing about NIR is you have some very good, strong signatures out there so you can calculate chemical concentrations fairly easily and break down the absorption or the transmission spectra into a combination of multiple different chemicals based on their concentrations.
What are the Most Exciting Developments in NIR Measurements?
Bonvallet: I think it has to do with the biologics, especially in the time we're living in, in this drug discovery phase, being able to get that fingerprint of what is in your solution, especially as vaccines are developed for viruses including COVID-19. NIR allows us to make measurements in situ in different processes, such as the drug discovery. It allows us to make Good Manufacturing Practices-type measurements where we're not interfering with that solution, and we're able to interface with it and make sure that things going into the body are safe.
Olmstead: What most excites me is the continued integration of NIR spectroscopy into commercial processes. As we think about how we move food or different substances into production to get it to the masses, NIR gives us a tool to help us make decisions about quality.
When we talk about using NIR for drug discovery, that's going into a larger manufacturing process where we're going to need to make decisions on very large volumes of material. When we talk about food quality, we think about the food we see at the grocery store before taking it home. But before that food ever gets to the grocery store, there are massive amounts of processing of onions, tomatoes, pomegranates and more. And decisions need to be made of how that food is to be distributed effectively, to give everybody the best quality they can. NIR and SWIR technologies really unlock the space to give us new ways to make better decisions about how we take care of our planet.