Example Analysis Using a Highly Sensitive Trace Moisture Analysis System Measurement of Moisture in Chlorofluorocarbon Gas and High-Purity Nitrogen Gas

Significance of the Topic

High-purity gases such as chlorofluorocarbons and nitrogen are fundamental in chemical synthesis and semiconductor manufacturing. Even trace levels of moisture can degrade performance, reduce yield, or damage sensitive equipment. A robust analytical approach for detecting moisture at the parts-per-million level is thus critical for quality control and process reliability.

Objectives and Overview of the Study

This study demonstrates the application of a highly sensitive gas chromatography system tailored for trace moisture analysis. It aims to show how the Shimadzu Nexis GC-2030 equipped with a Barrier Ionization Discharge detector and an ionic liquid capillary column can accurately quantify water in standard and pure gas samples at concentrations below 5 ppm.

Methodology and Instrumentation

The analytical setup combines a sampling system with gas and liquid sampling valves and the Nexis GC-2030 fitted with a BID-2030 detector. An ionic liquid capillary column (Watercol-1910, 0.25 mm I.D. 60 m, 0.20 μm film) enables efficient separation of water from other impurities. Key operating parameters include:

• Column temperature: 100 °C isothermal over 15 minutes
• Carrier gas: helium at 1.72 mL/min (linear velocity 30 cm/s)
• Injection mode: split 1:25 using a 1 mL sample loop
• Detector temperature: 230 °C with a 50 mL/min helium discharge gas flow

Main Results and Discussion

A calibration curve was established using helium standards containing 10 ppm and 100 ppm water. The system achieved a detection limit of approximately 0.8 ppm (S/N ≈ 3). Analysis of CF4 and high-purity N2 revealed moisture levels of about 3 ppm (S/N = 11.2) and 5 ppm (S/N = 18.3), respectively. Chromatographic traces showed clear baseline separation of water from gas matrix peaks, confirming minimal interference and high reproducibility.

Benefits and Practical Applications

The described system allows rapid, precise, and interference-resistant determination of trace moisture in specialty gases. Its low detection limit supports stringent quality requirements in semiconductor fabrication and specialty chemical production. Integration into routine quality control workflows can prevent equipment corrosion, improve process consistency, and reduce downtime.

Future Trends and Opportunities

Advancements in column chemistries and detector technologies may further lower detection limits and broaden the range of analytes. Automated sampling modules and real-time monitoring could be integrated to provide inline moisture surveillance. Combining this GC approach with complementary spectroscopic methods may deliver enhanced analytical coverage for complex gas mixtures.

Conclusion

The Shimadzu Nexis GC-2030 system with BID detection and an ionic liquid column offers a powerful solution for trace moisture analysis in high-purity gases. It delivers reliable quantification down to sub-ppm levels and addresses impurity-related challenges in demanding industrial environments.