High Performance Liquid Chromatograph for Ion Analysis - Ion Chromatograph

Importance of the Topic

Ion chromatography is a cornerstone technique in analytical chemistry for the selective and sensitive measurement of inorganic anions and cations. It underpins environmental monitoring (tap water, river and wastewater), industrial quality control, pharmaceutical research and food safety testing. Advances in suppressor and non-suppressor systems, detector technologies, and post-column derivatization continue to expand its practical applications and detection limits.

Objectives and Study Overview

This article reviews Shimadzu’s high-performance ion chromatograph offerings, tracing development from the first suppressor system in 1986 to modern suppressor/non-suppressor configurations. Key aims include:

• Comparing suppressor versus non-suppressor approaches for anion and cation analysis
• Presenting performance data on detection sensitivity, separation flexibility, calibration linearity and long-term stability
• Describing specialized system variations (dual-flow line, combustion IC, organic acid analysis)
• Highlighting Shimadzu’s LabSolutions software for integrated workflow management

Methodology and Instrumentation

Suppressor vs. Non-Suppressor Systems

• Suppressor systems employ electrodialytic units (e.g. ICDS-40A) or cartridge-type suppressors (HIC-SP) to reduce mobile phase conductivity, enhancing anion detection sensitivity and quantitation accuracy.
• Non-suppressor systems (HIC-NS) rely on pulse-free solvent delivery and precise thermal control to minimize baseline noise without suppressor maintenance requirements.

Key Instruments

• Ion Chromatograph HIC-ESP: Built-in electrodialytic suppressor with low carryover and precise injection control.
• Conductivity Detector CDD-10AVP: Temperature-regulated cell in column oven, low noise baseline.
• Solvent Delivery Pump LC-20ADSP: Inert pump with stable pressure, supports 100 nL/min–10 mL/min.
• Degassing Unit DGU-403: On-line low-volume degassing, stable eluent supply.
• Column Oven CTO-40S/20A: Forced air-circulation with electronic cooling (down to –15 °C), accommodates columns and detector cells.
• Autosampler SIL-20A/20AC: Full-volume injection, 0.1 µL minimum, inert kits available.
• Specialized Systems: Dual flow-line analysis, combustion IC for halogen/sulfur in solids, Nexera organic acid analysis with pH-buffered conductivity detection.
• Software: LabSolutions integrates method setup, sequence, continuous analysis, data processing and automated reporting.

Main Results and Discussion

Suppressor systems achieved superior anion sensitivity and stable calibration in low-concentration ranges, while non-suppressor systems provided greater freedom in mobile phase selection and simpler maintenance. Shimadzu’s ICDS-40A demonstrated robust, low-volume suppression and consistent peak intensity over hundreds of injections. Cation analysis showed comparable sensitivity across both systems, with non-suppressor offering more mobile phase versatility. The Nexera post-column pH-buffered conductivity method yielded high selectivity and uniform response for organic acids in complex matrices like wine.

Dual-flow line configurations and optional dual-channel conductivity detection enabled simultaneous anion and cation assays, streamlining routine water quality testing. The combustion IC unit facilitated trace halogen and sulfur measurement in materials by gasification and absorption sampling.

LabSolutions software simplified calibration curve validation, peak integration editing, statistical review and generated customizable individual or summary reports, reducing human error and saving time.

Benefits and Practical Applications

• Environmental monitoring: reliable detection of regulated anions/cations in water and soil extracts
• Pharmaceutical and food analysis: quality control of ionic impurities and organic acid profiles
• Industrial R&D: flexible mobile phase design for method development
• Materials testing: combustion IC for halogen and sulfur content in electronic components and plastics
• High-throughput routine testing: dual analysis systems and automated software workflows

Future Trends and Applications

Emerging directions include integration of ion chromatography with mass spectrometry for ultra-trace multi-element analysis, miniaturized portable IC systems for field testing, and AI-driven method optimization. Enhanced suppressor materials, faster columns, and advanced detectors will support higher throughput and lower detection limits. Digital laboratory ecosystems will further automate data exchange, compliance reporting and predictive maintenance.

Conclusion

Shimadzu’s ion chromatography platforms combine advanced suppressor/non-suppressor technology, precise thermal and solvent control, and versatile detection to meet diverse analytical needs. From environmental monitoring to sophisticated organic acid assays, these systems deliver high sensitivity, robust performance and streamlined workflows. Ongoing innovations in hardware, software and hybrid techniques will continue to expand the utility and efficiency of ion analysis.