Determination of cations and amines in hydrogen peroxide by ion chromatography using a RFIC (reagent-free) system

Importance of the Topic

Hydrogen peroxide is a critical reagent in semiconductor fabrication, requiring ultra‐high purity to prevent contamination of integrated circuits. Trace levels of inorganic cations and simple amines must be controlled at sub‐µg/L to meet industry specifications.

Objectives and Study Overview

This study aims to develop and validate a reagent‐free ion chromatography method for simultaneous determination of common inorganic cations (Li, Na, NH4, K, Mg, Ca) and amines (methylamine, ethylamine, dimethylamine, trimethylamine) in semiconductor‐grade hydrogen peroxide. The focus is on achieving low detection limits, high reproducibility, and elimination of organic modifiers in the eluent.

Methodology and Instrumentation

Sample Preparation

• Hydrogen peroxide samples treated with a platinum catalyst to decompose residual peroxide.
• Large‐loop direct injection of 1 mL per sample.

Chromatographic Conditions

• System: Thermo Scientific Dionex ICS‐2500 RFIC with EG50 eluent generator and EGC‐MSA cartridge.
• Column: Dionex IonPac CS17 4 × 250 mm with CG17 guard 4 × 50 mm.
• Eluent: Methanesulfonic acid gradient from 0.8 mM to 8 mM over 50 minutes.
• Flow rate 1 mL/min, column temperature 30 °C.
• Detection: Suppressed conductivity using CAES suppressor in recycle mode.

Main Results and Discussion

The CS17 column achieved baseline or near‐baseline separation of ten analytes without organic solvent. Calibration showed linear response (r2 > 0.99) across relevant concentration ranges. Method detection limits ranged from 0.005 µg/L for lithium to 0.330 µg/L for dimethylamine. Retention time RSDs were below 1% and peak area RSDs below 10%. Analysis of three platinum‐treated hydrogen peroxide samples revealed varying levels of cations and occasional detection of trimethylamine in two samples.

Benefits and Practical Applications

• Reagent‐free eluent generation ensures high precision and reproducibility of eluent composition.
• Elimination of organic modifiers improves sensitivity and simplifies waste handling.
• Direct large‐loop injection streamlines sample throughput.
• Suitable for quality control in semiconductor and related industries.

Future Trends and Potential Applications

Advances may include coupling RFIC with mass spectrometry for enhanced selectivity, further resin innovations to improve separation of challenging analytes, miniaturized or inline monitoring solutions for process control, and expansion to other trace contaminants in high‐purity chemicals.

Conclusion

The developed RFIC method with the Dionex IonPac CS17 column provides a robust, sensitive, and reproducible approach for trace analysis of inorganic cations and amines in semiconductor‐grade hydrogen peroxide, meeting stringent industry requirements.

References

1. Kerth J, Rattmann C, Jensen D. GIT-Labor-Fachz 2000;44(11):1324–1327.
2. Thermo Fisher Scientific Application Note 153, Monitoring for Trace Anion Contamination.
3. SEMI C30-06999 Specifications and Guidelines for Hydrogen Peroxide.