Getting to the Bottom of Vial Inserts

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—we stock a complete range ready to ship so you can stay focused on your lab work, not sourcing consumables. For an overview of vial selection, see our guide on selecting the right vial for chromatography. In this post, we’ll explore the different types of vial inserts, their advantages, and how to select the right insert for your application.

“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 for labs handling small-volume samples. Inserts reduce dead volume, enabling precise sample recovery and improved injection reproducibility. Made of glass or polypropylene, they come in multiple shapes and capacities to fit various vial types and analytical needs.

Types of Chromatography Vial Inserts

1. Flat-Bottom Inserts

Flat-bottom inserts are the most economical option. Their cylindrical shape provides the highest total volume (up to 400 µL), making them ideal for general applications where maximum recovery isn’t critical. The bottom sits flush with the vial base for easy insertion and consistent sampling.

2. Conical / Pulled-Point Inserts

Conical or pulled-point inserts feature a tapered end formed by pulling the glass to a narrow point. This shape slightly reduces volume but enhances sample concentration and allows better alignment with autosampler needles for consistent injections.

3. Mandrel-Point Inserts

Mandrel inserts are precision-formed by pressing a mandrel tip into the glass to create a sharply defined conical point. This allows nearly complete sample recovery—the autosampler needle can reach every last drop. These are the best choice for maximum recovery applications.

4. 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 protects the autosampler needle from damage and ensures consistent alignment during repeated injections.

Pre-Loaded Vials with Inserts

Loading inserts manually can be time-consuming. As an alternative to costly fused-insert vials, Chrom Tech offers pre-loaded autosampler vials with inserts—a cost-effective, time-saving solution. These come with inserts already assembled inside the vials, ensuring correct orientation and eliminating handling errors. For flat-bottom inserts, a visual line at the top confirms the correct facing. Don’t see your preferred vial-insert combo? Contact our support team to discuss custom options.

High-Recovery Options for Larger Samples

Chrom Tech’s high-recovery vials provide maximum sample retrieval for labs handling larger volumes or performing multiple re-injections. These designs feature internal geometry optimized for near-total recovery and are compatible with popular autosamplers like Waters HPLC systems.

Choosing the Right Insert for Your Vial

Proper pairing ensures a snug fit—using the wrong insert can cause it to sit unevenly or not fit at all. Vials and inserts are available in standard (5 mm ID) and wide-mouth (6 mm ID) openings; the insert must match the vial type. If unsure, measure your vial’s 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 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 isn’t listed on our in-stock page, our warehouse likely has it available. From specialized autosampler vials to simple components like luer adapters, Chrom Tech can help you find the right solution for your lab workflow.

Conclusion

Chrom Tech offers a full range of vials, caps, and inserts for HPLC and GC applications. Whether you need economical flat-bottom inserts, precision mandrel-point inserts, or high-recovery vial options, we’ve got you covered. Contact us to request a quote or learn more about our extensive inventory of chromatography consumables.