Thermo Scientific Dionex IC Pure water purification system

Significance of the Topic

The quality of water used in ion chromatography directly influences detection limits, baseline stability, and overall method reproducibility. By integrating an on-demand ultrapure water source, laboratories can eliminate reagent contamination, reduce downtime, and achieve trace to ultratrace ion analysis in environmental, pharmaceutical, and industrial settings.

Aims and Study Overview

This work introduces the Thermo Scientific Dionex IC Pure water purification system, designed to supply reagent-free ion chromatography systems with continuous, high-purity water. It aims to redefine the “just add water” concept by allowing either tap or pretreated laboratory water to be automatically converted to ultrapure quality, improving operator convenience and analytical performance.

Methodology and Instrumentation

The Dionex IC Pure system employs a multi-stage purification train:

• Pre-treatment with reverse osmosis and activated carbon to remove inorganic ions, organics, and chlorine.
• Inline ultrafiltration (pore size <10 nm) and sterile 0.2 µm filtration to eliminate particulates and microorganisms.
• UV photochemical oxidation (185/254 nm) to reduce total organic carbon below 5 µg/L and inactivate residual microbes.
• Mixed-bed anion and cation exchange polishing cartridge to achieve resistivity up to 18.2 MΩ·cm.

The system features an internal 5 L feed tank, an external 20 L refillable reservoir, automated level control, and dual-pressure outlets (3 psi for eluent generation, 30 psi for suppressor regeneration). A touchscreen interface displays conductivity, TOC readings, and consumable status.

Used Instrumentation

• Thermo Scientific Dionex IC Pure water purification system
• Reverse osmosis membrane module with activated carbon cartridge
• Inline ultrafilter and sterile 0.2 µm filter
• UV oxidation lamp (185/254 nm)
• Dionex ERS 500e electrolytic suppressor
• RFIC platforms: Dionex ICS-5000+, Integrion HPIC, ICS-4000, and Integral systems

Main Results and Discussion

The Dionex IC Pure system consistently meets ASTM D1193 Type 1 and ISO 3696 Grade 1 standards:

• Resistivity: up to 18.2 MΩ·cm
• Conductivity: 0.055 µS/cm
• Total Organic Carbon: <5 µg/L
• Bacteria: <1 CFU/mL
• Sodium, chloride, silica: below detection limits (<1 µg/L; <3 µg/L respectively)

In validation runs, overlayed chromatograms of anion standards showed retention time RSD <0.1 % and peak area RSD <1.0 %. Continuous on-demand water avoided conductivity drift observed in bottled DI water over 24 hours.

Benefits and Practical Applications

• Eliminates manual eluent bottle preparation and contamination risks
• Enhances sensitivity and peak resolution by minimizing background conductance
• Reduces system downtime due to fouling or microbial growth
• Supports trace (µg/L) and ultratrace (ng/L) ion quantification in water quality monitoring, food safety, and pharmaceutical QA/QC
• Accommodates multiple RFIC instruments with synchronized water delivery

Future Trends and Opportunities

Advancements may include miniaturized purification modules for benchtop or portable IC systems, integration with laboratory information management systems (LIMS) for automated quality reporting, and real-time monitoring using IoT sensors. Coupling on-demand ultrapure water generation with AI-driven predictive maintenance and data analytics could further streamline high-throughput ion analysis in regulated and research environments.

Conclusion

The Dionex IC Pure water purification system provides a turnkey, reagent-free solution for producing ultrapure water on demand, meeting stringent international standards. Its robust multi-stage design and seamless integration with RFIC platforms enhance analytical performance, operational efficiency, and data quality for trace ion analysis.

Reference

• ASTM D1193: Standard Specification for Reagent Water
• ISO 3696:1987 Water for analytical laboratory use