How to Choose the Best Storage Vials

Solving Storage Challenges with F217 Liners

Screw thread vials are common for LC sample analysis as well as sample or standard storage. But is there a difference between autosampler vials and storage vials? Typically, autosampler vials used for LC analysis are 2 mL with a 9 mm screw thread, open top cap and septa. On the other hand, storage vials come in sizes ranging from 2 mL up to 32 mL, and the closures are typically solid top, lined caps with different threading.

Figure 1 Autosampler Vial Cap vs Solid Top Storage Cap

2 mL Autosampler Vial vs. 2 mL Storage Vial

Both 2 mL autosampler vials and 2 mL storage vials are 12x32 mm in size. For most of our LC customers that prefer a screw thread vial, we recommend a 9 mm wide mouth vial, as they offer a 40% wider opening than the 8-425 screw thread vials. However, for storage of volatile compounds or long term storage (for standards, etc.), we recommend the smaller opening 8-425 option. The 8-425 vials have more threads per inch than the 9 mm vials, which keeps a tighter seal.

Figure 2 8-425 vs 9 mm vs 10-425 vial threading

Large Storage Vial Sizes

Storage vials are sometimes referred to as “dram vials” because of their historical association with the measurement unit known as a “dram” (which was widely used in pharmacy and medicine prior to the metric system). In today’s world, a dram vial is more-or-less interchangeable with a large storage vial (4 mL or larger).

It is important to note that the larger vials will require a larger cap size. In our ordering table, you’ll find a list of various vial sizes with their associated threading size.

How to Choose a Septa/Liner Material

You’ll notice that the liners for solid top caps are different than the material used in septa for open top caps. This is mainly because solid top caps for storage vials are typically designed for reuse. A top choice for storage vials is our F217-lined caps. This polyolefin foam is sandwiched between two layers of polyethylene. The PE is chemically compatible for most solvents, while the foam layer allows for the closure to be torqued with 20 lbs. of foot pressure and once the pressure is backed off, the liner goes back to its original shape.

For sample analysis, the most common septa material is a PTFE with silicone combination. The PTFE layer offers additional chemical inertness to protect the sample from contamination. These closures are also available with a slit septa, which allows for easier needle penetration during sample analysis.

Other Miscellaneous Vial Types

While most of our customers use typical HPLC and GC vials, we do offer an assortment of specialty vials for a variety of applications including environmental and PFAS testing, sensitive applications requiring low adsorption vials, and more. We also offer accessories such as vial racks, crimpers and decappers to be paired with our large selection of chromatography vials. If you have any questions, our helpful product specialists are ready to assist.