The 2mL clear borosilicate glass vial with a 9-425 screw thread and PTFE/silicone septum isn't just popular. It's the single most widely used chromatography vial configuration on the planet.
Screw top vials account for approximately 50% of the global chromatography vial market. The 9-425 thread is the dominant format for modern HPLC and LC-MS autosamplers, and clear borosilicate glass accounts for over 60% of the material type share. When you combine those numbers, one configuration stands out: the 2mL clear glass 9-425 screw vial with PTFE/silicone septa.
Why this configuration dominates
Universal compatibility. The 9-425 thread fits virtually every modern autosampler from Agilent®, Waters®, Shimadzu®, Thermo™, and beyond. One vial, every instrument."
Borosilicate glass performance. Type I borosilicate offers excellent chemical resistance, low extractables, and the inertness required for trace-level analysis. Clear glass allows visual confirmation of sample volume, colour, and particulates before injection.
PTFE/silicone septa. The PTFE layer provides chemical inertness and prevents septum bleed into samples. The silicone layer delivers the resealability needed for multiple injections. Together, they offer the ideal balance of performance for routine HPLC and LC-MS work.
Screw thread reliability. Unlike crimp or snap closures, screw caps allow hand tightening without tools, provide consistent seal pressure, and are easily resealed after sampling. For high-throughput labs processing hundreds of samples daily, that simplicity matters.
Where labs are using them
Pharmaceutical QC, environmental monitoring, food safety testing, clinical analysis, and forensic toxicology. Anywhere HPLC or LC-MS is the analytical technique, the 9-425 screw vial is likely the consumable running through the autosampler.
The global autosampler vial market is currently valued at over $1.6 billion and growing at around 7% annually. HPLC vials represent 55% of that market. Demand is being driven by expanding pharmaceutical workflows, tighter regulatory requirements, and the growth of PFAS and environmental testing programmes.
What to look for when choosing a supplier
Not all 9-425 vials are equal. Key quality markers include:
- Consistent dimensional tolerances (critical for autosampler arm pickup)
- Low particulate contamination
- Batch-to-batch consistency in wall thickness and thread dimensions
- Mass spec certification for sensitive LC-MS applications
- Septa that maintain seal integrity across multiple needle penetrations
Our range
At Chromatography Direct, we offer a range of 9-425 screw thread vials, available in clear or amber, with or without label patch, and supplied in packs of 1,000. Our UltraClean preassembled option pairs the vial with a blue 9-425 screw cap and red PTFE/white silicone septum, ready to use straight from the pack with no contamination risk from manual assembly.
High-quality consumables at unrivalled prices. That's not a slogan; it's what we deliver every day.