Quality control and regulatory factors in the chemical industry necessitate inline monitoring of key operations. High pressures and temperatures or sensitive processing environments in this industry often make grab sampling and offline process monitoring impractical or impossible. In some instances, it may be necessary to isolate the sample cell from electronics as well. In pharmaceutical and biotech manufacturing, at-line cleaning verification is a critical process to ensure the prevention of contamination and cross-contamination of residues between manufacturing runs. This is also true for clean-in-place (CIP) processes used in food and beverage manufacturing. Inline monitoring of the rinse water can help reduce water usage, sanitizer consumption, wastewater costs and process time while maintaining the required level of sterilization.
UV spectroscopy is a robust, non-contact process which can be used for inline monitoring of a majority of organic compounds. While absorption spectroscopy is more universally applicable, fluorescence can offer high sensitivity and selectivity. Traditionally, deuterium or xenon flash lamps have been used for spectroscopy since these light sources supply ample light in the UV wavelengths. However, these light sources emit light in a broad spectrum which needs to be filtered out to measure or monitor specific compounds. In addition, these lamps require expensive power supplies and hence, have a large system cost. Deuterium lamps have a relatively low lifetime and consequently, require more frequent replacement. Xenon flash lamps have a poor stability of light output and therefore a lower limit of detection.