Name: 9 mm Screw Top Caps for 9-425 GC Vials
Brand: Laboratory Consumables

Description

In gas chromatography (GC) and autosampler-based analytical workflows, sample integrity is highly dependent on reliable vial sealing. Volatile compounds, solvent evaporation, and septa failure can introduce variability and compromise analytical accuracy during injection sequences.

High-throughput laboratories require consistent, chemically resistant sealing systems that maintain sample stability throughout storage and automated injection. Poor cap-septa compatibility or low-quality sealing components often lead to leakage, analyte loss, and inconsistent chromatographic results.

9 mm Screw Top Caps for 9-425 GC Vials are designed to provide secure and reproducible sealing for chromatography workflows. The PP cap combined with PTFE/red silicone bonded septa ensures chemical resistance, mechanical durability, and compatibility with standard autosampler vial systems used in GC analysis.

Specification

Cap Color	Blue
Cap Material	Polypropylene
Cap Size	9 mm
Certified	No
Includes Septa	Yes
Pre-Slit Septa	No
Product Type	Caps & septa
Repeat Injections	No
Septa Layering	Bi-Layer
Septa Material	PTFE/red silicone
Technique	GC
Thread Size	9-425
UNSPSC Code	41121806
Vial Type	Screw

Features

9 mm screw cap designed for 9-425 GC vial compatibility
Blue polypropylene cap body provides chemical resistance and mechanical stability
PTFE/red silicone bi-layer septa for inert sealing and injection penetration
Bonded septa structure ensures consistent alignment and leak reduction
Optimized for gas chromatography and autosampler injection systems
Supports volatile and semi-volatile sample handling workflows
Suitable for single-injection analytical procedures

Applications

Gas Chromatography (GC) sample sealing and injection
Volatile Organic Compound (VOC) analysis
Environmental testing (air, water, soil extracts)
Pharmaceutical residual solvent analysis
Food flavor and aroma compound analysis
Chemical and analytical research workflows
Autosampler-based high-throughput chromatography systems

Technical Insight

The PTFE layer provides a chemically inert barrier that reduces solvent interaction and analyte adsorption, while the red silicone layer ensures elasticity for syringe penetration during autosampler injection. This dual-layer septa design is widely used in GC vial caps to balance chemical resistance and sealing performance.

Frequently Asked Questions

What are 9 mm screw caps used for?

They are used to seal 9-425 GC vials in gas chromatography workflows, ensuring sample stability and preventing evaporation or contamination.

What is PTFE/red silicone septa used for?

PTFE provides chemical resistance, while silicone allows needle penetration and resealing during autosampler injection.

Are these caps compatible with GC autosamplers?

Yes, they are designed for standard 9 mm / 9-425 GC autosampler vial systems.

Can these caps be used for multiple injections?

They are designed for single-injection workflows. Repeated puncturing may reduce sealing performance.

What type of samples are suitable?

They are suitable for volatile and semi-volatile samples including environmental, pharmaceutical, and chemical analysis applications.

9 mm Screw Top Caps for 9-425 GC Vials – PTFE/Red Silicone Septa, Autosampler Compatible