Selecting Chromatography Vials - Glass or Plastic?
In Chromatography, essentially you have two options for your vials – glass or plastic. Of course, the material you decide on must be suitable for the intended application, and is of paramount importance that it’s correct.
We’ve therefore written a comprehensive overview of both options below to help you ascertain which to use.
Glass Vials – the facts
· Glass is pure – meaning it will have no trace of contaminants
· Heat resistant – Can be heated to over 500°C
· It’s fragile – increasing the risk of breakages
· More expensive
· Relatively inert surface – compatible with many solvent systems
· Wide range of styles and sizes
The glass used for chromatography vials is Borosilicate Glass and can come in either an amber colour or clear. Borosilicate glass contains boron trioxide which gives it a very low coefficient of thermal expansion. This means it will not crack under extreme temperature changes like regular glass. It can therefore be heated to over 500°C, making it suitable for High Temperature Liquid Chromatography (HTLC), autoclaving and derivatization.
Glass vials can come in both amber and clear. Amber coloured vials are used to protect the Vial’s contents from UV light, preventing UV degradation of certain chemicals. Slightly more obviously, clear vials allow for much greater visibility of the Vials contents.
Glass vials are also more labour intensive and more expensive due to having to pre-wash the glass vials with sterile water, drying them before use and have higher disposal costs.
Glass is, however, very versatile coming in a wide variety of styles and sizes. Its relatively inert surface makes it compatible with many different solvent systems.
Plastic Vials – the facts
· The type of plastic is important – polypropylene and polymethylpentane (TPX) are most common
· Maximum temperature range of 135°C – 175°C
· Higher chemical resistance – non-reactive with most sample chemistries
· Lighter weight construction
· Durability – dramatically reduce the risk of breakages
· Cheaper to purchase
· Lower disposal costs
· Optimal choice when working with proteins
· Ideal for Ion Chromatography applications
The leading materials in plastic vials are Polypropylene and Polymethylpentane (TPX). Polypropylene is seen as the best option for chemical resistance allowing short term storage and is the most popular plastic of choice. On the other hand, TPX has better temperature resistance, up to 175°C, compared to 135°C for Polypropylene. Further differences are that Polypropylene is translucent whilst TPX is transparent, allowing for greater visibility.
Plastic vials are available in a wide range of volumes and configurations. Their higher durability dramatically decreases breakages and they are more affordable than glass vials. They are non-reactive with most sample chemistries. For a comprehensive chemical resistance chart for Polypropylene, please follow the link below.
Plastic vials are also better for some methods of Chromatography such as proteomic assays, making plastic vials the optimal choice when working with proteins, and are ideal for Ion Chromatography applications.
The disposal of plastic vials is a lot cheaper and safer. Incineration of the samples while sealed makes for easy disposal and limits any potential exposure to hazardous materials.
There’s 3 main factors that are going to determine the correct choice in material for your Chromatography vials.
1) Temperature – Is the temperature too high for plastic?
2) Sample chemistries – Is the glass/plastic chemically compatible?
Plastic has a very definite temperature limit which is far surpassed by glass – 175°C compared to over 500°C. So if your processes involve HTLC, autoclaves or derivatization then glass is the obvious choice. For proteomic assays and Ion Chromatography we’d recommend Polypropylene vials. Determining chemical resistance to sample chemistries will require either research or further testing.
Overall plastic vials present a practical alternative to glass providing a number of advantages, including – weight reduction, far fewer breakages and lower & safer disposal costs.
We hope the information above helps you determine the best Chromatography vials for you and your lab. For more information, please contact us at email@example.com