How to Choose and Seal a Sample Vial?

For general sample collection, storage, and transportation in the labs, Hawach sample vials are available not only in a variety of sizes and colors but also in different volume capacities and material compositions. You can find them sterile, non-sterile, or autoclavable.

Choosing the correct sample vial for your application is important. With lots of options to choose from, it’s also complicated to select them because there are many factors you should consider. When you choose a sample vial, the most important factor is the material of the vials.

If the glass vials are pure, that means they don’t have any contaminants in the components, such as metal, which might interfere with an experiment. Glass is also resistant to heat, which makes glass vials can be heated to over 500°C。 That’s why we choose glass vials for common use better than plastic vials.

The glass sample vials can be in the color of clear or amber. The amber sample vials are the best for the easily damaged chemicals, as the color of amber can protect the contents in the vials from UV light which might damage certain chemicals. At the same time, clear vials can provide the best visibility of chemicals.
2ml Screw Thread Top Sample Vials Crimp Top Sample Vials
How to seal the sample vial? HAWACH has summarized four mainly used sample vial sealing methods.

1. Screw top sample vial
The screw-top sample vial provides a low-evaporation, reusable, and less-harmful sealing method than the crimp cap, and no additional tools are required. Threaded cap sample vials are distinguished by different thread specifications, which are defined by the Glass Packaging Association (GPI). The threaded sample vial consists of two parts: a threaded bottle and cap septa.

Threaded sample vial caps are available as either an open perforated cap designed for automatic sampling, a solid cap designed for sample storage, or an integrated PP cap. This piercable screw cap is designed for a single injection because it does not require assembling the cap septa, which can save time for experiment preparation.

2. Crimp top sample vial
Crimped sample vials require aluminum caps for sealing, which are relatively inexpensive. When properly clamped, they provide the best seal for long-term storage. The jaw cover cannot be reused. The cap-pressing device is required to seal and the capping device is to remove the sealing cap.

Cappers and disappear are suitable for aluminum caps of different specifications, including an adjustable precision capper for selection. The adjustable manual capping device provides an adjustable stop point on the handle to ensure that the tightness of the cap is consistent every time. Adjust the screw in the metal jaws to change the jaw depth.

The correct jaws are critical because too-tight jaws can cause the septum to deform toward the center, damaging the needle and the Teflon layer to form holes larger than the correct jaws. Loose jaws can cause the septum to be punctured or the sample to evaporate.

The manual decapper can safely and quickly remove the aluminum cover with just one grip. The design of decap pliers is similar to pliers, providing an economical option. When the sample contains harmful substances, it is necessary to use the decapper, because the use of the decapper is not easy to cause leakage.

3. Snap-top sample vial
Snap-top vials can be used with crimp caps or bayonet caps, and no tools are required when using bayonet caps. Since its tightness is not as good as crimp top bottles or screw-top bottles, it is recommended for short-term sample storage or non-volatile samples.

4. Cap-pressing sample vial
For HPLC autosampler or other autosamplers that do not require a manipulator to move the sample vial, it is a more economical choice than screw-top vials: cap-pressing sample vial. Most such bottles are sold with PE (polyethylene) caps with star-shaped cuts that are easy to puncture.