Real Time TOC System in the PURELAB® Chorus 1

Importance of the topic

The control of Total Organic Carbon in purified water is a critical quality parameter for laboratories and industrial processes. Continuous monitoring of organic content ensures water meets stringent purity requirements and prevents contamination in sensitive applications.

Objectives and overview

This technology note describes the implementation of real-time TOC measurement in the PURELAB Chorus 1 system. It contrasts conventional batch TOC analysis with the continuous monitoring approach and evaluates its performance against a standard TOC analyzer.

Methodology and instrumentation

The real-time TOC method calculates organic carbon by measuring resistivity before and after UV photoxidation. Key components of the system include

• Primary purification pack to remove bulk contaminants
• Resistivity sensor to record preoxidation water purity
• UV photoxidation chamber to convert organics to CO2
• Secondary resistivity sensor to record postoxidation purity
• Polishing purification pack for final water treatment

Main results and discussion

The PURELAB Chorus 1 updates TOC readings every two seconds during recirculation or dispensing, compared to six to eight minutes for conventional analyzers. Comparative trials with a Sievers 820 analyzer showed close agreement, with deviations within one ppb over a 1 to 10 ppb range. Dynamic response data demonstrate elimination of prolonged unknown TOC intervals during dispensing.

Benefits and practical applications

Real-time monitoring delivers several advantages:

• Instant feedback on organic load allows immediate corrective action
• High measurement frequency ensures uninterrupted data during use
• Comparable accuracy to dedicated TOC analyzers without offline testing delays
• Enhanced system diagnostics by identifying sudden organic spikes

Future trends and potential uses

Emerging directions in TOC monitoring include integration of advanced UV-LED oxidation modules, miniaturized sensor arrays for point-of-use validation, and data analytics for predictive maintenance. Coupling real-time TOC data with other purity metrics may enable comprehensive water quality management platforms.

Conclusion

The PURELAB Chorus 1 real-time TOC monitoring system offers a rapid, accurate, and user-friendly approach to track organic impurities in ultrapure water. Its continuous measurement capability enhances process control and safeguards critical applications against contamination risks.

Reference

ELGA LabWater,VWS UK Ltd Technology Note TN28,2013