PROCESS-WATER CHARACTERIZATION USING DISCRETE ANALYZERS AND ION CHROMATOGRAPHY

Importance of the topic

Maintaining reliable process-water quality is essential across many industries because water impurities can corrode equipment, impair product quality, increase downtime and generate significant operating costs. Rapid, repeatable and sensitive monitoring of multiple water parameters across treatment and reuse streams is therefore a core requirement for process control, preventive maintenance and regulatory compliance.

Objectives and overview

This webinar-style document reviews analytical strategies for comprehensive process-water characterization using two complementary technologies: automated discrete analyzers (Thermo Scientific Gallery platform) for high-throughput multi-parameter screening, and ion chromatography (Thermo Scientific Dionex systems) for targeted, high-sensitivity determinations and complex-matrix separations. The goal is to show how combining both approaches — or using the integrated Disc-IC system — can shorten turnaround time, reduce sample and reagent consumption, extend dynamic range, and mitigate matrix interferences.

Methodology and approach

The material contrasts two analytical workflows and explains method optimizations used for process-water applications:

• Discrete photometric and electrochemical analyses: The Gallery discrete analyzer automates reagent addition, incubation and photometric or electrochemical readout in parallel, enabling a walkaway workflow for many routine parameters (pH, conductivity, alkalinity, hardness, silica, iron, fluoride, sulfate, ammonia, phosphate, cyanide, Kjeldahl N, etc.).
• Ion chromatography (IC): Dionex IC systems (including Reagent-Free IC configurations) are applied for trace anion/cation analysis, corrosion monitoring, and matrix-challenged samples. Key IC strategies include use of small-particle IonPac columns for higher throughput, concentrator/preconcentration columns to remove bulk matrix and concentrate analytes, suppressed conductivity and alternative detectors (UV-Vis, electrochemical) to avoid matrix effects, and gradient eluents generated by electrochemical generators (EGC cartridges) to improve separation and reproducibility.

Representative method adjustments discussed include increasing IC flow rates (e.g., from 0.3 to 0.5 mL/min) to shorten run times while maintaining resolution on 4 µm particle columns, employing gradients to sharpen peaks, and using concentrator columns plus large rinse volumes to remove high-abundance matrix constituents (e.g., boron, lithium) while retaining trace analytes.

Used instrumentation

• Thermo Scientific Gallery Discrete Analyzer (Gallery/Gallery Plus) — photometric module (Xenon lamp and configurable filter wheel) and electrochemistry module (ECM) for pH and conductivity.
• Thermo Scientific Dionex ion chromatography systems — including Reagent-Free IC (RFIC), IonPac column family (examples: AS22-Fast-4 µm, AS28-Fast-4 µm, CS5A for cations), concentrator columns and EGC (eluent generation cartridges).
• Thermo Scientific Disc-IC integrated system — combined discrete analyzer and ion chromatography workflow for automated, high-throughput comprehensive water analysis.

Main results and discussion

Key performance findings and operational advantages highlighted in the material:

• Throughput and sample economy: The Gallery discrete analyzer can perform up to about 350 tests per hour, uses ~200 µL per test (microliter-scale assays) versus tens of milliliters for conventional wet-chemistry methods, and generates far less waste.
• Parallel multi-parameter screening: Gallery enables simultaneous photometric measurements of up to ~20 parameters plus electrochemical measurements (pH 2–12; conductivity 20 µS/cm–112 mS/cm), reducing operator time and lowering training requirements.
• High sensitivity and low background with IC: Dionex RFIC systems with high-purity electrochemically generated eluents deliver low-baseline noise enabling determinations at ppb and ppt levels for corrosive anions and other trace ions.
• Faster IC separations without loss of resolution: Small-particle IonPac columns (4 µm) tolerate higher linear velocities; increasing flow from 0.3 to 0.5 mL/min nearly halved run time while preserving peak shape and separation, improving sample throughput.
• Managing interferences and overloaded matrices: Using concentrator columns with large rinse volumes removes bulk matrix components (e.g., hundreds to thousands ppm boron or lithium) and concentrates trace analytes to levels detectable by IC; alternative detectors and high-capacity columns prevent loss of small peaks due to adjacent large signals (for example separating ethanolamine from ammonium).
• Gradient eluents and reagent-free generation: EGC cartridges enable on-line eluent production (reduces manual reagent handling and contamination risk), and gradients improve peak sharpness and reproducibility versus isocratic separations.

Benefits and practical applications

• Operational efficiency: Combining parallel discrete analyses for routine parameters with targeted IC for trace/speciation work minimizes total analysis time and labor.
• Resource and waste reduction: Microliter-scale assays and reagent-free eluent generation reduce sample consumption, chemical use and hazardous waste volumes.
• Improved process control: High-frequency screening and online-capable IC allow timely response to water-quality excursions, helping prevent corrosion, scaling and product quality loss.
• Broader analytical coverage: The integrated approach supports routine QA/QC, corrosion monitoring (anions, inhibitors, transition metals), scaling risk assessment (silica, calcium), and wastewater characterization.

Future trends and potential applications

Anticipated developments and opportunities for process-water analytics:

• Greater integration and automation: Fully automated platforms (e.g., Disc-IC) will continue to streamline sample-to-result workflows and reduce operator dependence.
• Online and real-time monitoring: Robust IC and discrete modules adapted for continuous sampling will enable closed-loop process control and predictive maintenance.
• Green analytical practices: Wider adoption of reagent-free eluent generation, lower-volume assays and reduced waste aligns with sustainability goals.
• Analytics and data fusion: Integration of high-throughput measurements with process data, advanced chemometrics and AI models will improve anomaly detection and predictive diagnostics.
• Miniaturization and field-deployable systems: Advances in column and detector technology may enable more portable, on-site process-water testing for rapid decision-making.

Conclusion

A combined strategy using automated discrete analyzers for routine high-throughput screening and ion chromatography for high-sensitivity, matrix-robust determinations provides a practical, scalable solution for comprehensive process-water characterization. The approach reduces sample and reagent consumption, shortens analysis time, and improves data quality across diverse industrial matrices. Integration of these technologies (Disc-IC) and further moves toward automation, on-line monitoring and reagent-free chemistries will strengthen process control and reduce both operational risk and environmental footprint.

References

• American Chemical Society / C&EN Media Group. Webinar material: Process-water characterization using discrete analyzers and ion chromatography. Thermo Fisher Scientific (webinar and application notes referenced in source document).