Comprehensive and fully automated water analysis

Importance of the topic

Monitoring water quality is essential for environmental protection, public health, and compliance with regulatory requirements. Contaminants in drinking water, industrial effluents, and food production can adversely impact ecosystems and human well-being. An integrated and automated approach that combines multiple analytical techniques elevates efficiency, reproducibility, and data quality in routine water analysis.

Objectives and study overview

This work presents a fully automated system (TitrIC 4) that integrates direct measurement, titration, and ion chromatography into a single analytical unit. The primary goal is to streamline drinking water analysis—demonstrated on tap water from Herisau, Switzerland—while offering adaptability for food, electroplating, or pharmaceutical applications. Key aims include user-friendly operation, flexible sample handling, and protection against interferences.

Methodology and instrumentation

The system workflow comprises three analytical modules:

• Direct measurement of temperature, conductivity, and pH with an Aquatrode Plus pH electrode.
• Titrimetric determination of acid capacity and calculation of p (mol/L HCl) and m (EDTA/complexometric) values using a Titrando device and 0.05 mol/L EDTA, 0.2 mol/L TRIS with acetyl-acetone.
• Ion chromatographic quantification of fluoride, chloride, nitrate, sulfate, and other anions using an 881 Compact IC pro with Metrosep A Supp 5 column and sequential suppression.

Instrumentation used

• 881 Compact IC pro with sequential suppression
• 815 Robotic USB Sample Processor XL (rack for 59×120 mL vessels)
• 809 Titrando with Dosinos (800) and Conductivity Module 856
• 802 Rod stirrer
• Reagents: 0.1 mol/L HCl, 0.05 mol/L EDTA, 0.2 mol/L TRIS/acetyl-acetone
• IC parameters: eluent 3.2 mmol/L Na2CO3/1.0 mmol/L NaHCO3, flow 0.8 mL/min, loop 20 µL, suppressor 100 mmol/L H2SO4
• Software: tiamo™ and MagIC Net™, LIMS-compatible data management, ion balance calculation, automated backup

Main results and discussion

Analysis of ten replicate tap water samples yielded:

• Fluoride: mean 0.05 mg/L (RSD 4.7%)
• Chloride: 8.76 mg/L (RSD 0.3%)
• Nitrate: 10.63 mg/L (RSD 0.3%)
• Sulfate: 5.41 mg/L (RSD 0.4%)
• pH 6.76 (RSD 0.13%), conductivity 590.7 µS/cm (RSD 1.6%), Ca2+ 82.7 mg/L (RSD 1.3%), Mg2+ 17.3 mg/L (RSD 2.3%)

Results demonstrate high precision, minimal sample handling, and comprehensive ionic profiling in a single automated run.

Benefits and practical applications

The combined system offers:

• Fully automated workflow from sample intake to result storage
• Enhanced throughput and reproducibility
• Flexible method sequences and extension to additional ions or titrations
• Protection of samples from environmental contamination

Applications span municipal water monitoring, industrial QC, food safety, and pharmaceutical water analysis.

Future trends and potential uses

Upcoming developments may include integration of inline ultrafiltration for particle removal, expansion to trace‐level analysis using preconcentration, real-time data analytics with AI-driven anomaly detection, and remote operation under IoT frameworks. Adaptation to non-aqueous matrices or complex industrial wastes is also feasible.

Conclusion

The TitrIC approach unifies direct physical measurements, titration, and ion chromatography into one robust platform for automated water analysis. The system achieves reliable, high-throughput determination of key ionic parameters with minimal manual intervention. Its modular design and flexible software make it a versatile solution for diverse analytical requirements in environmental and industrial settings.

References

No specific literature references were cited in the original text.