How To Choose the Right Vial for Chromatography
In general, modern chromatography liquid autosamplers accept 12 x 32mm vials, so we will assume that a 12 x 32mm vial is compatible with your autosampler (Headspace autosamplers accept 20mm wide autosampler vials). Here, we have outlined the simple steps in selecting the best chromatography vial for your analysis.
Step 1: Determine Vial Closure Style
- Screw Thread Vials
Screw thread vials are typically used for HPLC and LCMS analysis. Screw thread vials do not require additional tools for attaching the cap, nor for removing the cap.
- Crimp Vials
Crimp Vials are commonly used as a GC Vial for gas chromatography analysis. Crimp Vials are the gold standard when concerned with sample evaporation. Crimp Vials are also required when chain-of-custody or tamper-proof closures are required. When using crimp vials, we recommend the electronic vial crimper for ergonomic crimping of your GC vials.
- Snap Top Vials
Snap Top Vials are convenient for lab technicians and are sometimes preferred over screw thread vials. Snap Top vials are typically used for HPLC or LCMS analysis, and the closure is simply pressed down on the vial to make the seal.
Step 2: Determine Volume of Vial
2mL Autosampler vials are the most common vial type.
If you have a limited amount of sample, you can use a 2mL autosampler vial with a compatible vial insert. Vial inserts come in different designs:
Tapered inserts hold up to 250µL of sample and allow maximum sample recovery due to the taper. Flat-bottom inserts are an economical option and hold up 400µL of sample.
If you have plenty of sample but want to be able to re-inject multiple times, we recommend high-recovery vials.
These high-recovery vials we see used a lot with Waters HPLC autosamplers, and our high-recovery vials are compatible with Waters HPLC autosamplers.
Step 3: Determine Vial Material
- Glass Autosampler Vials
The most common type of Autosampler vial is the Type 1 Borosilicate Glass, which represents the least reactive glass. Type 1 glass has the least pH shift (lowest leaching characteristics) and a Coefficient of Expansion = 33 for Clear and 51 for Amber
- Plastic Autosampler Vials
Plastic vials are an economical option when you need a limited volume vial. Plastic Vials are most often Polypropylene (PP). Polypropylene Vials are compatible with Acetone, Ethyl Acetate, Methanol, Isobutyl alcohol, methanol, and methyl ethyl ketone. They are incompatible with cyclohexane, ethers, dichlorobenzene, pentanes, methylene chloride, and trichlorobenzene.
Less common Plastic Vial Options:
Polyethylene (PE) Vials are compatible with Acids, alcohol, and bases. PE is incompatible with benzene, chlorobenzene, acetic anhydride
TPX Polymethylpentene is a lightweight, functional polymer with a unique combination of transparency, heat, and chemical-resistant properties.
Step 4: Determine Clear or Amber Vial
Clear Vials are the most common. Amber Glass Vials or Black Polypropylene Vials should be used with light-sensitive samples.
Why choose screw thread autosampler vials over crimp vials?
The advantage of screw thread vials over crimp vials is the ease of removing the screw thread closure prior to the vial’s disposal. Screw thread vials are common for HPLC and LCMS analysis as well as storage of standards. When storing standards, it is common to use a solid top screw thread vial since the lab technician would open and close the vial over a period of time to pipette out standards.
At Chrom Tech, we love talking about vials and helping our customers determine the BEST vial for their chromatography analysis—please reach out today to one of our Vial Experts.