Getting to the Bottom of Vial Inserts

If you’ve got questions about chromatography vials, you’re in the right place. Vials are our specialty here at Chrom Tech, and we’ve got a number of blogs on the subject. For those of you who are trying to determine which vial to use for your application, I recommend checking out our blog on choosing a vial for a chromatography application. We have a number of popular autosampler vials in stock and ready to ship on a moment’s notice. We know that you should be focusing your efforts on the work in the lab and not worrying about getting vials and other consumables. Chrom Tech also stocks a number of vial inserts to fit in various types of vials. In this blog post, I’ll discuss the different vial inserts that we carry.

"Inserts keep the samples contained to a smaller volume and make it easier to extract the sample from the vial for analysis"

Why Do Labs Use Vial Inserts?

Vial inserts are often used in laboratories that are working with small amounts of samples. Inserts keep the samples contained to a smaller volume and make it easier to extract the sample from the vial for analysis. The inserts can be glass or polypropylene, just like the vials, and come in many different shapes and sizes to accommodate various sample and vial types.

What are the Different Types of Inserts?

1. Flat-bottom Inserts

Flat-bottom vial inserts are an economical choice for labs that need an insert but might not need every last drop of sample. Because of their cylindrical shape, they have the greatest volume of the insert options (relative to other insert shapes). The bottom of the flat-bottom inserts rests flat against the bottom of the vial. and can hold a volume of up to 400 µL of sample.

2. Conical/Pulled-point Inserts

Pulled-point, or commonly called conical, inserts feature a tapered bottom, limiting the volume slightly more than the cylindrical shape of the flat-bottom inserts. These types of conical inserts are manufactured by pulling the glass into a tapered (conical) point, while leaving a flat surface on the inside of the point.

3. Mandrel Inserts

Mandrel inserts have the most precise tips available for vial inserts. Manufacturers shape the insert by pushing a mandrel tip into the glass to create the taper. This creates a conical-shaped point inside the insert so that every last drop of sample can be reached by the needle point of the autosampler. This is our recommended insert for when you need maximum sample recovery for analysis.

4. Conical Inserts with a Spring

Conical inserts, both pulled-point and mandrel, can come with a polypropylene spring on the bottom. The spring acts as a stabilizer to keep the insert centered in the vial and protecting the needle from hitting the insert.

What if I Don’t Want to Load the Inserts Myself?

This is a great question. You might already be familiar with fused-insert vials, which are great for reducing time spent loading your inserts into your vials but can be quite costly. With the cost of the fused inserts in mind, we have an better option for some of our more popular vials. Chrom Tech is proud to be a leader in improving customer experience in the lab, and we now offer pre-loaded inserts in autosampler vials. These vials come packaged with the inserts already in the vials. For the flat-bottomed inserts, there is a line on the top of the vial insert for visual confirmation that your insert is facing with the open side up. If you don’t see the preloaded vial and insert combination you need, we can potentially add yours to our offering – just reach out to our support team to see if we can accommodate.

Is There an Option for High Recovery with Large Sample Volumes?

We offer a high-recovery vial for labs who have plenty of sample to work with but want the option to re-inject sample multiple times. Most commonly, we see customers with Waters HPLC autosamplers using these types of vials. Our high-recovery options are also Waters compatible.

Does it Matter Which Insert I Pair with My Vial?

Yes! In fact, if you don’t pair the vial with the right insert, it will either be too loose or won’t fit at all! As you may know, autosampler vials are available in wide mouth and standard opening sizes. Likewise, the inserts are available in wide mouth and standard opening and must be paired with the respective vial size. We have inserts in all shapes and sizes for both wide and standard opening vials. If you’re unsure what type of vial your lab uses, you can always measure the internal diameter (ID) of the vial mouth. Standard mouth opening vials have an ID of 5mm, while wide mouth vials have an ID of 6mm. If you have any trouble finding the appropriate vial, our friendly support team is always happy to help. As always, we want the process to be as easy as possible so that you can focus on the work that matters.

"If you don’t pair the vial with the right insert, it will either be too loose or won’t fit at all"

Where Can I Find In-Stock Inserts?

You can find inserts and other in-stock chromatography consumables all in one simple place on the web! Check out the LC and GC Supplies In Stock page for a whole list of vials, caps, inserts, and other popular items for HPLC and GC. Chrom Tech carries a number of other popular chromatography consumables such as HPLC and GC fittings and columns, pumps, syringes, and so much more. Although you may not see these on our in-stock page we do have a stocking warehouse full of these consumables as well. Perhaps you’re looking for something as simple as a luer adapter to connect a low-pressure line; our team can help you find the best option for your application. Be sure to reach out with any and all HPLC and GC questions, and our support team will get you pointed in the right direction.

In conclusion,

Chrom Tech carries a myriad of vials, caps, and inserts for various chromatography applications. Depending on your sample size and recovery needs, we can help you find the best insert to pair with your autosampler vial. From economical flat-bottom inserts to conical and mandrel point inserts, we’ve go you covered. Reach out for more information, or to get a quote for our vials, caps, and inserts.

About the Author

Jess has been with Chrom Tech since graduating from the University of Redlands in 2017 with a BS in chemistry. She works remotely for our team as the marketing coordinator, and spends her personal time exploring the beaches and mountains in California with her dog, Nisswa.