Carbon Dioxide - Experis ultra-high purity gases Technical specification

Importance of the Topic

Ultra-high purity carbon dioxide is essential in analytical chemistry and process applications where trace contaminants can compromise accuracy and reproducibility. High-purity CO2 is widely used in supercritical fluid extraction, chromatography, calibration, and process control, ensuring reliable and interference-free results.

Objectives and Article Overview

This article presents the technical specifications of Air Products’ Experis range of UHP (ultra-high purity) CO2 grades. It highlights purity levels from 99.9% to 99.9995%, impurity limits, analytical verification protocols, packaging options, and compliance with pharmacopoeial standards.

Methodology

Impurity analysis follows two main verification approaches: batch testing of cylinders from the same production lot and individual cylinder analysis. Pharma-grade products comply with EP, USP, and JP monographs, accompanied by hard-copy certificates under ISO 9001:2008. Key impurities monitored include oxygen, nitrogen, carbon monoxide, water, THC, NOx, and total sulphur, verified against stringent ppm limits.

Instrumentation Used

• Liquid CO2 cylinders (sizes x10s, x47s, 11x47s)
• High-purity brass pressure regulators (single and two-stage, with vaporizer heating options)
• Manual control valves (with or without pressure gauges)
• High-purity manifolds (single-wing, two-wing manual and automatic changeover)

Main Results and Discussion

Experis CO2 grades exhibit consistent purity performance: Premier 3.0 (99.9%), Premier 4.5 (99.995%), Pharma 4.5 (99.995%), and UltraPure 5.5 (99.9995%). Physical properties such as gas density (1.831 g/L at 20 °C), vapour pressure (56.22 bar), and liquid density are documented. Detailed packaging data cover dimensions, weights, and fill quantities. Traceability is ensured through unique lot numbers linking cylinders to fill location, raw materials, and QC records.

Benefits and Practical Applications

• Optimum purity for supercritical fluid extraction (SFE) and chromatography (SFC)
• Minimized analytical background for high-sensitivity measurements
• Flexible packaging sizes and optional helium headspace for specialized applications
• Pharma compliance with certified analyses supports regulated environments

Future Trends and Possibilities for Use

Advancements may include even tighter impurity specifications, on-site purity monitoring, integration with automated gas delivery systems, expansion into novel analytical platforms, and sustainable cylinder designs to reduce environmental footprint.

Conclusion

The Experis UHP CO2 portfolio delivers rigorous impurity control, comprehensive analytical verification, and versatile delivery formats, meeting the needs of analytical, pharmaceutical, and industrial processes with full traceability and quality assurance.