Revolutionising TOC process analysis with TOC-4200

In the world of industrial automation, processes are becoming increasingly hands-off, but certain industries, particularly those dealing with large volumes of water, require strict monitoring. Process analyser technology (PAT) plays a vital role, with the Shimadzu TOC-4200 offering advanced capabilities in online total organic carbon (TOC) analysis.

PAT’s advanced sensors automate complex analytical tasks, a critical asset in processes involving water treatment, use and transport. While basic sensors handle physical parameters, process analyzers like the TOC-4200 handle complex measurements. They require some human interaction, mainly for maintenance, but the benefits are immense. PAT provides real-time assessment of substance concentrations that are critical to process integrity, equipment protection and environmental safety.

At the core of PAT is the ability to monitor both intentional and unintentional substance changes. Many monitored substances are organic compounds found in natural ingredients and water contaminants. Efficient monitoring requires fast, reliable and automated parameter analysis. This is where TOC comes in as a key parameter.

TOC, which represents the sum of organic carbon-containing molecules, has significant potential. Once performed primarily in laboratories, TOC analysis has moved online, driven by automation and accelerated results. The Shimadzu TOC-4200 is at the forefront of this evolution.

The TOC-4200 operates as an online TOC analyzer that incorporates an automated sampling station. The station draws process water for analysis, adapting to water quality factors such as particle content or salinity. The flexibility of Shimadzu’s sampling modules ensures adaptability to various sample types. With the ability to monitor multiple points, a single analyzer can connect up to six sample streams for automated or on-demand measurements.

An essential part of TOC analysis is the distinction between organic and inorganic carbon. The Shimadzu TOC-4200 addresses this with the non-purgeable organic carbon (NPOC) method. The integrated sample pretreatment unit (ISP module) acidifies the sample, converting carbonates and bicarbonates into CO₂. Gas purging expels CO₂, setting the stage for analysis.

Once inorganic carbon is removed, the TOC-4200 automatically injects the sample onto a platinum catalyst at 680 °C, oxidising organic compounds to CO₂. This process is carefully controlled, with condensation and removal of combustion by-products. The resulting CO₂ reaches a sensitive CO₂-selective NDIR detector for quantification. External calibration allows calculation of TOC concentration. Rinsing between analyses prevents carry-over and ensures accuracy. Optionally, related sum parameters such as total carbon (TC), total inorganic carbon (TIC), purgeable organic carbon (POC) or total nitrogen (TNb) can be determined.

A highlight of the TOC-4200 is the automatic dilution function, which extends the measuring range beyond calibration limits if required. This feature facilitates dynamic adjustment and calibration from high-concentration/long shelf life standard solutions.

In conclusion, the Shimadzu TOC-4200 advances process analysis through online TOC assessment. It goes beyond the confines of the laboratory to provide real-time insights into organic carbon levels. This technology maintains process integrity, protects the equipment and contributes to environmental preservation. Shimadzu’s innovation demonstrates the efficiency of automation in modern industries.