As the 'Helium Shortage 4.0' continues to grip the scientific community, analytical chemists are pivoting to hydrogen as an alternative carrier gas. This shift has ignited a spirited recent debate on Chromatography Forum, centering on the optimal material for hydrogen gas tubing—stainless steel or copper?
A Chromatography Forum user recently grappled with a dilemma while relocating a 7890 GC (dual FID). The lab's existing setup employed copper for air, nitrogen, and helium lines but used stainless steel for hydrogen. The question raised was both simple and crucial: Is stainless steel indispensable for hydrogen lines, or might copper be an adequate substitute? Given the cost disparity between the two materials, the question has significant implications.
Pros and Cons
The ChromForum discussion provides a detailed analysis of the merits and limitations of both copper and stainless steel for gas tubing. One long-time copper user highlighted its cost-effectiveness and widespread adoption in labs. Yet another participant cautioned that copper can become brittle, particularly when hydrogen is involved, leading to potential leaks or failures.
Conversely, stainless steel was lauded for its durability and chemical resistance. One contributor noted that manufacturers including Agilent specifically recommend stainless steel for hydrogen lines. However, even stainless steel can be susceptible to hydrogen embrittlement.
Practical Advice from the Bench
The Chromatography Forum discussion is rich with practical advice from seasoned professionals. One user, GC3, shared insights from his company's analytical chemists. They emphasized the importance of using new and clean copper lines, especially when switching from helium to hydrogen. Hydrogen can strip away deposits left by helium, affecting the performance of the flame ionization detector (FID).
Another user, CE, pointed out that copper tubing can become hard and brittle over time due to oxidation, posing a risk of leaks. On the other hand, stainless steel tubing was praised for its long-term stability. Dr. No added a new angle, questioning whether the risk of pit corrosion in steel had been considered, highlighting that material choice isn't just about immediate costs but also long-term safety and performance.
As the forum discussion makes clear, there's no one-size-fits-all answer. The choice between copper and stainless steel will depend on a myriad of factors, from budget constraints to long-term safety considerations. What's certain is that as carrier gases evolve, so too will the materials we use to contain them.
For those eager to engage further with this topic, we invite you to join the ongoing discussion on Chromatography Forum.