Ion Chromatography Applications in the Power Industry

Significance of the Topic

Ion chromatography (IC) is critical for monitoring trace ionic species in power plant water cycles, ensuring equipment integrity, safety, and regulatory compliance. Accurate determination of anions and cations at µg/L to ng/L levels supports corrosion control, process optimization, and environmental protection.

Objectives and Study Overview

The paper reviews advanced IC techniques applied in power industry matrices such as ultrapure water, condensates, polisher effluent, and borated reactor water. It highlights reagent-free IC (RFIC), automation strategies, large-volume injection, on-line sample preparation, and electrolytic sample purification (RFIC-ESP). Key goals include improved sensitivity, reduced contamination, and streamlined workflows.

Methodology and Instrumentation

• Eluent Generation: Electrolytic production of KOH/NaOH eluent using Dionex EluGen™ cartridges.
• Suppression: ASRS® ULTRA II and CR-ATC/CR-TC for anion/cation removal and background reduction.
• Sample Preparation: AutoPrep™ system for on-line calibration and large-volume concentration (up to 40 mL) via concentrator columns (AC10, AG4A).
• RFIC-ESP Module: Electrolytic water purifier integrated with ICS-2100/3000 for low-background ultrapure water.
• Columns: IonPac® AS, AG, CS series microbore (2 mm) and standard (4 mm) columns for anion/cation separations.
• Detection: Suppressed conductivity detectors with external water or recycle modes; post-column derivatization for silica and metals.

Main Results and Discussion

• Ultrapure Water Analysis: Achieved detection limits below 5 ng/L for major anions/cations with RFIC-ESP.
• Large-Volume Injection: 750–1000 µL direct injection in 2 mm columns enhanced mass sensitivity by up to fourfold.
• Power Plant Samples: Condensate and polisher effluent analyses identified trace fluoride, chloride, nitrate, sulfate, organics, and phosphate at µg/L levels.
• Borated Water: On-line CR-CTC II enabled removal of high lithium background, detecting anions and trace organics in reactor coolant water.
• Amines and Hydrazine: CS14/CS16 columns and optimized gradients resolved amines, ethanolamine, hydrazine, and morpholine in secondary circuit water down to single-digit ppb.
• Automation: AutoPrep sequences provided contamination-free calibration and sample prep, reducing manual intervention and labor costs.

Benefits and Practical Applications

• Enhanced Sensitivity: Trace levels (< ppt) of ions achievable for corrosion monitoring and control.
• Automation and Reliability: Reduced human error, consistent multi-point calibrations, and high throughput.
• Versatility: Applicable to diverse matrices including UPW, cooling water, condensate, and reactor coolant.
• Regulatory Compliance: Meets stringent feedwater quality standards in fossil and nuclear power plants.

Future Trends and Applications

• Real-Time Online Monitoring: Integration of IC with process control for continuous water quality surveillance.
• Miniaturization and Microfluidics: Development of lab-on-a-chip IC for field deployable analysis.
• Mass Spectrometry Coupling: IC-MS hybrids for speciation and high-resolution trace analysis.
• AI-Driven Data Analytics: Automated interpretation, anomaly detection, and predictive maintenance.

Conclusion

Advanced reagent-free and electrolytic IC technologies, combined with automated sequence control and on-line sample preparation, deliver robust, low-blank, high-sensitivity analysis crucial for power industry water management. These approaches reduce workload, improve reliability, and support regulatory and operational needs.

Used Instrumentation

• Dionex ICS-2100 and ICS-3000 integrated with RFIC modules (EGC II KOH/NaOH, CR-ATC, CR-TC).
• AutoPrep™ Automated Sample Preparation System.
• IonPac® AS, AG, CS column families (2 mm microbore, 3–4 mm standard).
• Concentrator columns: AC10, AG4A, AC15.
• Suppressed conductivity detectors and electrolytic water purifier modules (RFIC-ESP).