How to Select Chromatography Vials
Many factors play a role in deciding which vial is best for your needs such as sample volatility, sample amount, and light sensitivity. Choosing the right vial is imperative to increasing ROI and operability and decreasing sample degradation due to improper collection or storage. Follow this guide for tips on how to select chromatography vials for the best results.
If your lab uses an autosampler, make sure to use autosampler vials that are compatible with your specific autosampler.
Chromatography autosamplers for liquid samples have standardized on the 12 x 32mm vial. For liquid chromatography, the most common vial is the 9mm screw thread vial. This vial has an opening that is large enough for ease of pipetting, while having the neck/closure that is recommended to use with the autosamplers that are common in the marketplace. Some people prefer a snap cap vial and closure, as the closure can be easily popped off.
When evaporation is a concern or when chain of custody is required, the crimp cap closure is the industry standard.
Proper Closures and Caps
Closures and caps come in many different types to accommodate various samples, testing methods, and storage needs. For example, solid top screw thread vials with a PTFE/F217 closure are commonly used for storage as the foam extruded between the layers of polyethylene is able to be torqued with 20 lbs. of pressure and can be return to almost 100% of its original shape once the pressure is backed off for a solid seal.
Before purchasing chromatography vials, you should determine the volume of your sample size to ensure you purchase the right vial. The size of the vial can drastically alter results if not sized properly. When sample is limited or if repeated injections are necessary, vial inserts reduce the volume of the vial for maximum sample recovery.
Chromatography vials can be made of glass or plastic. Chrom Tech’s vials are made of Type 1 Borosilicate glass which is the least reactive glass and have the least pH shift.
Plastic vials are typically made of polypropylene (also available in Polyethylene or TPX) and are commonly used as an economical option for limited volume applications. However, plastic can be better for some chromatography methods such as proteomics assays.
If you are unsure of which material is best for your application, reach out to one of the Chrom Tech vial experts for a product recommendation.
Glass vials come in two different color options: clear or amber. If you are concerned about light sensitivity during your test, using a glass amber vial is the best choice for you. If your sample is not sensitive to light or you need your sample to be visible during testing, using a clear vial will work best.
For environmental sample containment, Chrom Tech offers EPA/VOA vials in three different classes. Class 1 standard containers are assembled with liner and closure without washing. Class 2 (pre-cleaned) and Class 3 (certified) are both processed according to the EPA recommended wash procedures. These containers are washed with laboratory grade biodegradable, non-phosphate detergent, rinsed with ASTM Type 1 de-ionized water, oven dried, and assembled in a contaminant free environment. The difference between class 2 and 3 is that class 3 vials will contain a certificate of analysis from an independent laboratory that certifies the containers cleanliness to ensure impartial results.
Considering all the attributes listed above will help you determine how to select chromatography vials that are best suited for your lab.