The inherent characteristics of NIR spectroscopy make it a logical choice for process analysis applications. As with other spectroscopy techniques, NIR offers instantaneous noncontact analysis of liquids and powders, and is able to perform analyses through glass. Relative to mid-infrared spectroscopy, NIR can penetrate much further into a sample, which makes it more amenable for use in the analysis of bulk materials and samples.

One characteristic of NIR that was once a detriment, but which is now becoming an advantage is its complex spectra. Advancements in software, and improved data analysis algorithms and analysis methods can now leverage these data rich spectra to provide a wealth of information, including identification and concentration of the compounds that are present. Method development researchers are now discovering a myriad of compounds and even parameters that can be analyzed using NIR, including pH.

A range of configurations are used for process NIR instruments. Simple fixed-filter NIR sensors can be used for applications with only one or two compounds of interest. More advanced process NIR spectrometers are based on diode array detectors, which require no moving parts. Fourier Transform (FT)–NIR systems utilize interferometers to disaggregate the spectrum.

One of the most common applications of process NIR to monitor moisture and fat content in foods and, more recently, the moisture content of pharmaceutical and nutraceutical powders during the drying process. These applications generally utilize simple fixed-filter NIR instruments because they are only concerned with one or two components. More advanced instruments are used for multicomponent analysis in the petroleum refining industry. Such advanced multicomponent instruments are also used for monitoring wet chemical baths in semiconductor and solar cell manufacturing, and in pharmaceuticals for monitoring final blending and tablet uniformity. A newer application of NIR is the monitoring of bioreactor fermentation in the biopharmaceutical industry. Advancements in NIR data analysis now offer the ability to monitor basic parameters such as pH and dissolved oxygen content in such processes, while also allowing manufacturers to monitor most other parameters or compounds.

There are quite a few vendors that compete in the process NIR market due to their development of online instrumentation based on their benchtop NIR instrumentation. However, the top four vendors account for well over 60% of the market. FOSS NIRSystems alone accounts for more than a third.

The market for process NIR was around $110 million in 2009. Growth declined slightly during the recession due in large part to the pullback by the petroleum industry. A rebound in the oil industry, as well as growth in solar cell, electronics and biopharmaceutical manufacturing should lead to close to double-digit growth in demand over the next several years.

Process NIR at a Glance:

Leading Suppliers

• FOSS NIRSystems

• Thermo Fisher Scientific

• Bruker

Largest Markets

• Petroleum

• Pharmaceuticals

• Food Processing

Instrument Cost

• $20,000–$80,000