Choosing the right chromatography vials and inserts ensures reliable, efficient sample handling in HPLC and GC analysis. Chrom Tech specializes in autosampler vials and vial inserts and stocks a complete range ready to ship so you can stay focused on your lab work rather than sourcing consumables. For an overview of vial selection, see our guide on selecting the right vial for chromatography.
“Inserts keep the sample contained in a smaller volume and make it easier to extract every drop for analysis.”
Why Do Labs Use Vial Inserts?
Vial inserts are essential when laboratories work with small-volume samples. Inserts reduce dead volume inside autosampler vials, enabling precise sample recovery and improving injection reproducibility.
Most inserts are manufactured from borosilicate glass or polypropylene and are designed to fit inside standard autosampler vials. By concentrating the sample at the bottom of the vial, inserts ensure autosampler needles can consistently reach the sample during injection.
Using inserts is especially beneficial when:
- Sample volumes are below ~400 µL
- Maximum sample recovery is required
- Multiple injections are needed from a limited sample
- Accurate autosampler needle positioning is critical
Types of Chromatography Vial Inserts
Flat-Bottom Inserts
Flat-bottom inserts are the most economical option. Their cylindrical design provides the highest total volume capacity (up to approximately 400 µL). These inserts are ideal for general laboratory applications where maximum sample recovery is not critical.
The flat base sits flush with the vial bottom, allowing consistent autosampler needle access while maintaining a stable insert position.
Conical / Pulled-Point Inserts
Conical or pulled-point inserts feature a tapered bottom formed by pulling the glass to a narrow point. This shape slightly reduces the usable volume but improves sample concentration at the bottom of the insert.
Because the autosampler needle naturally aligns with the tapered bottom, pulled-point inserts help improve injection consistency when working with low-volume samples.
Mandrel-Point Inserts
Mandrel inserts are precision-formed by pressing a mandrel tip into the glass to create a sharply defined conical point. This design allows the autosampler needle to reach nearly every drop of the sample.
Mandrel-point inserts are the preferred choice for maximum recovery applications and are commonly used when samples are extremely limited or expensive.
Conical Inserts with a Spring
Spring inserts include a small polypropylene spring at the base to keep the insert centered within the vial. This stabilizer prevents the insert from shifting during injection cycles.
Maintaining insert alignment protects autosampler needles and improves injection consistency during repeated runs.
Pre-Loaded Autosampler Vials with Inserts
Manually loading inserts into vials can be time-consuming in high-throughput laboratories. As an alternative to expensive fused-insert vials, Chrom Tech offers pre-loaded autosampler vials with inserts.
These assemblies arrive with inserts already positioned inside the vial, reducing handling time and minimizing orientation errors. For flat-bottom inserts, a visible alignment line confirms the correct orientation.
If your preferred vial and insert combination is not listed, contact our support team to discuss available options.
High-Recovery Alternatives for Larger Samples
For applications involving larger sample volumes or multiple re-injections, Chrom Tech also offers high-recovery autosampler vials. These designs use optimized internal geometry to reduce dead volume while eliminating the need for separate inserts.
High-recovery vials are compatible with many autosampler platforms, including Waters HPLC systems.
Choosing the Correct Insert for Your Vial
Matching the insert to the vial opening is essential for proper fit and stability.
- Standard vials: 5 mm internal opening
- Wide-mouth vials: 6 mm internal opening
Using the wrong insert size may cause the insert to sit unevenly or fail to fit inside the vial. If you are unsure which insert fits your vial, measure the internal diameter or contact Chrom Tech for assistance.
“If you don’t pair the vial with the right insert, it will either be too loose or won’t fit at all.”
Where to Find In-Stock Vial Inserts
Chrom Tech maintains an extensive inventory of in-stock chromatography supplies including vials, caps, and inserts ready for immediate shipment.
We also stock essential HPLC and GC accessories such as fittings, pumps, syringes, and tubing. Even if an item is not listed on the in-stock page, our warehouse likely has it available.
Conclusion
Chrom Tech offers a complete range of autosampler vials, caps, and vial inserts for HPLC and GC laboratories. Whether you need economical flat-bottom inserts, high-recovery mandrel-point inserts, or assembled vial-insert combinations, we can help you select the right solution.
Contact our team to request a quote or learn more about our chromatography consumables inventory.
Want a complete overview of vial selection? Visit our Chromatography Vials resource center.