Comprehensive tap water analysis with TitrIC 2

Importance of the Topic

Comprehensive analysis of tap water quality is essential for ensuring public health, regulatory compliance and environmental protection. Automated methods that combine ion chromatography, titration and direct measurements increase laboratory efficiency and data reliability.

Objectives and Study Overview

The study demonstrates a fully automated workflow using the TitrIC 2 system to measure major anions (fluoride, chloride, nitrate, sulfate), cations (sodium, potassium, calcium, magnesium), pH, conductivity and titration parameters (p-value, m-value) in tap water samples. Analysis time is reduced by performing parallel ion chromatography and titration.

Methodology and Instrumentation

The method uses:

• Ion chromatography with Metrosep SUPP 4 – 250 and Metrosep C 2 – 100 columns
• Carbonate/tartaric acid – dipicolinic acid eluent (2.4 mM Na2CO3, 2.0 mM NaHCO3, 7 mM tartaric acid, 1.5 mM dipicolinic acid)
• Chemical suppression (50 mM sulfuric acid)
• Parallel titration for pH endpoints (pH 8.2 and pH 4.3) using HCl
• Automated dosing and acidification via Dosino modules (10 mL, 50 mL)
• Software control and integration with tiamo and IC Net 2.3

Main Results and Discussion

Reproducibility for 10 tap water replicates:

• Anion RSD between 2.06 % and 3.09 %
• Cation RSD between 3.11 % and 3.59 %
• pH 7.74 ± 0.039, conductivity 572 ± 12.1 µS/cm, m-value 5.51 ± 0.17 mmol/L
• Ionic balance difference +0.74 % indicating good agreement

Analysis time per sample is 9 minutes.

Benefits and Practical Applications

The combined TitrIC 2 workflow delivers high-throughput and reliable multiparameter water analysis. It eliminates sample preparation steps, reduces hands-on time and provides integrated data for quality control in water treatment, environmental monitoring and industrial process control.

Future Trends and Applications

Emerging directions include:

• Extension to oxygenated halides and trace ions
• Online coupling with sampling devices for unattended monitoring
• Integration with mass spectrometry for compound identification
• Cloud-based data management and remote control
• Miniaturization for field-deployable systems

Conclusion

TitrIC 2 offers a flexible and efficient platform for comprehensive tap water analysis, achieving accurate quantification of ions, titration parameters and direct measurements in a single automated run.

Reference

Application Bulletin 302 e, Metrohm Ltd., Herisau, April 12 2006