In modern chemical and biotechnological industries, the ability to accurately monitor process streams in real-time is crucial for optimizing efficiency, ensuring quality, and maintaining safety. Traditional methods like chromatography, while precise, often involve time-consuming sample extraction and offline analysis, creating delays in process control. A more effective solution lies in bringing the analysis directly to the process line.
Our latest application note demonstrates a powerful method for achieving this: using a fiber-optic Attenuated Total Reflection (ATR) probe for in-line Mid-Infrared (Mid-IR) spectroscopy.
The Power of the Molecular Fingerprint
The Mid-Infrared spectral region is often called the "molecular fingerprint" region because it contains unique absorption features corresponding to the fundamental vibrations of molecules. This allows for highly specific identification and quantification. Even molecules with similar structures, such as ethanol and methanol, exhibit distinct spectral signatures in this range, making it possible to differentiate and measure them accurately within a mixture.
Overcoming the Challenge of Liquid Analysis
Directly analyzing liquids, especially aqueous solutions, with traditional infrared spectroscopy can be challenging due to the strong absorption of water. This is where our fiber-optic ATR probe technology provides a significant advantage. The ATR technique allows for measurements to be taken directly within the liquid sample, regardless of its opacity or high absorption. By bringing the analysis directly into the process fluid, it enables continuous, real-time monitoring without the need for sampling or complex sample preparation.
A Case Study: Quantifying Ethanol and Methanol
In our study, we focused on simultaneously quantifying ethanol and methanol in a two-component aqueous solution. By connecting a diamond ATR fiber-optic probe to an FTIR spectrometer, we developed a robust calibration model. The results demonstrated exceptionally high accuracy, with a root mean square error of prediction below 0.15% for both alcohols.
This high level of precision highlights the suitability of the technology for demanding industrial applications, including the control of distillation processes. The use of fiber optics adds another layer of flexibility, allowing the spectrometer to be placed in a safe control room while the robust probe is integrated directly into the production pipeline.
This combination of Mid-IR spectroscopy and fiber-optic ATR probes provides a robust, accurate, and efficient solution for real-time process monitoring. It empowers industries to move beyond delayed, sample-based analysis and embrace continuous, in-line process control.
For a detailed look at the methodology and results, download our full application note.
