carriergas

Carriergas are gases used to transport a sample or precursor through a system without reacting with it under operating conditions. In analytical chemistry, a carriergas moves vaporized samples through a chromatographic column to the detector. In industrial processes, it conveys precursors or reactive species to a reaction zone or deposition surface, often while diluting or stabilizing the stream.

Common carriergases include helium, hydrogen, nitrogen, and argon. Choice depends on inertness, viscosity, and thermal properties, as well as instrument compatibility and cost. Helium offers high efficiency for many GC separations but is scarce and expensive. Hydrogen is inexpensive and fast but flammable. Nitrogen is economical but can reduce separation efficiency; argon is inert and compatible with many detectors but pricier.

Purity is critical; most systems require ultra-high-purity grades with very low levels of oxygen, moisture, and hydrocarbons. Gas supply conditions—pressure, flow rate, and regulator accuracy—directly affect performance. Applications span gas chromatography and GC–MS, as well as deposition and etching processes in materials science, where the carrier gas helps deliver precursors and influence film or surface quality.

Safety and handling: carriergases are stored in pressurized cylinders and require proper regulators, leak testing, and adequate ventilation. Inert gases can displace oxygen and pose asphyxiation risks; hydrogen, while flammable, demands strict safety controls. Compliance with local and international standards governs labeling, cylinder integrity, and purity specifications.