Comprehensive water analysis with TitrIC flex II

Significance of the Topic

This application note addresses the growing demand for fully automated, multi‐parameter water quality testing using a single platform. Comprehensive water analysis is critical in environmental monitoring, industrial process control, and regulatory compliance. By integrating titration, direct measurements, and ion chromatography, laboratories can streamline workflows, reduce manual handling, and ensure consistent data quality.

Objectives and Study Overview

The main goal of this study was to demonstrate the capabilities of the TitrIC flex II system for routine analysis of well water samples. Key objectives included:

• Quantitative determination of major anions (fluoride, chloride, nitrate, sulfate) and cations (sodium, potassium, calcium, magnesium)
• Measurement of pH, temperature, conductivity, total hardness, and acid/base capacities (m-value and p-value)
• Calculation of ion balance to verify analytical accuracy

Methodology

The workflow combines ion chromatography (IC) for anion and cation separation with potentiometric titration and direct sensors for other parameters. A sample robot equipped with Pick&Place modules and Dosino units handles sample introduction, temperature and conductivity measurement, pH sensing, and titrant addition. Inline ultrafiltration protects the IC columns while automated calibration and dosing ensure reproducibility.

Used Instrumentation

• OMNIS Advanced Titrator (no stirrer) with Conductivity Module
• Sample Robot: Main Pick&Place unit, two Pick&Place modules, peristaltic pump, rod stirrer
• IC System: Two 930 Compact IC Flex units with ovens, inline ultrafiltration, Dosino for suppressor and regenerant delivery, dual conductivity detectors
• Columns: Metrosep A Supp 17 and guard for anions, Metrosep C 4 and guard for cations
• Electrodes: Multiparameter dAquatrode with Pt1000, 5-ring conductivity cell

Main Results and Discussion

The system delivered precise quantitative results for all target analytes in well water. Representative values included 27.7 mg/L nitrate, 80.8 mg/L calcium, conductivity of 537.8 µS/cm, pH 7.68, and a total hardness of 2.92 mmol/L. The ion balance was within 0.55 %, confirming method accuracy. Chromatographic separation was achieved within 25–26 minutes per sample, enabling high throughput.

Benefits and Practical Applications

• Fully automated pipeline minimizes human intervention and risk of contamination
• Single‐system approach reduces instrument footprint and maintenance
• High reproducibility and accuracy support regulatory compliance
• Flexible configuration allows expansion to other water matrices or additional ions

Future Trends and Potential Applications

Advances in microfluidic integration and miniaturized sensors will further enhance automated water analysis. Cloud‐based data handling and machine learning algorithms may enable real‐time monitoring and predictive maintenance. Expansion into drinking water, wastewater, and industrial process streams will broaden application scope.

Conclusion

The TitrIC flex II platform offers a comprehensive, automated solution for multi‐parameter water analysis. By combining ion chromatography with titration and direct measurements, it streamlines laboratory workflows, delivers reliable results, and supports diverse quality control needs.

References

Metrohm Application Note S–387, Version 1, February 2020