-4H-Jena engineering introduces commercially purified mCP to improve seawater pH data comparability

Jena, Germany: -4H-Jena engineering GmbH has become the only commercial provider with the ability to offer large-scale purification of meta-Cresol Purple (mCP) for spectrophotometric seawater pH measurement. The capability is now available in direct support of its CONTROS HydroFIA™ pH analyser, addressing a long-standing challenge in marine carbon system monitoring.

Spectrophotometric pH measurement using indicator dyes such as mCP is widely recognised for its precision and suitability for high-quality ocean monitoring. However, impurities in commercially available indicator dyes can introduce systematic bias, even when apparent precision is high. Manufacturer and batch-dependent variability has been shown to shift reported pH values by up to 0.01 units, limiting data comparability and undermining confidence in long-term time series.

Until now, there has been no commercially available, scalable source of purified mCP. Laboratories and monitoring programmes have either relied on limited research-grade supply or undertaken their own purification, often at significant cost and effort. These approaches are typically time-intensive and difficult to scale for global monitoring needs.

By establishing the world’s first commercial in-house purification capability, -4H-Jena engineering is removing this bottleneck for users of the CONTROS HydroFIA™ pH system. The company can now deliver rigorously quality-controlled, ready-to-use purified mCP as part of its overall solution, reducing the technical and operational burden on customers while improving traceability and comparability of pH data

“High-quality indicator dye is fundamental to unlocking the full potential of spectrophotometric pH measurements,” says Dr. Katharina Seelmann, Project Manager Research & Technology Management, -4H-Jena engineering GmbH. “By offering purified mCP as a commercially available product, we are eliminating a key source of systematic bias and giving monitoring programmes greater confidence in the reliability and comparability of their data. This is an important step towards more robust long-term ocean observation.”

For operators of the CONTROS HydroFIA™ pH analyser, the development strengthens the system’s position as a complete and traceable measurement solution. By combining proven spectrophotometric technology with a secure supply of high-purity indicator, -4H-Jena engineering enables more consistent data across platforms and programmes, supporting applications from coastal monitoring to open-ocean research and high-resolution time-series studies.

Visitors to Oceanology International 2026 are invited to discuss this new capability and other recent -4H-Jena engineering developments on stand B201.

Ends

Media enquiries

-4H-JENA engineering GmbH

E-mail: info@4h-jena.de

Phone: +49 3641 2887 0

About -4H-JENA engineering

-4H-JENA engineering is an established German engineering company providing expert technologies and services in diverse markets. Through its Marine Technologies division, 4H-JENA engineering develops, designs, and distributes measuring instruments and complete systems for the investigation of (sea) water for more than 20 years. These include the established CONTROS brand sensors as well as FerryBox systems that sample for various parameters. In addition to the easily configurable and standardised product portfolio, -4H-JENA engineering also develops customised solutions, which are tailored to the respective requirements of the customer. https://www.4h-jena.de/en/start/

By establishing the world’s first commercial in-house purification capability, -4H-Jena engineering is removing this bottleneck for users of the CONTROS HydroFIA™ pH system.