How to choose a HPLC vials

  In chromatographic testing, laboratory personnel often face the trouble of choosing experimental consumables.How to choose a sample vial suitable for testing is very critical. Using a wrong sample vial may cause bad test results. It may also damage the sample or the chromatograph.

  There are so many styles of sample vials, how should we've chosen? This article will show you how to choose vials. Doing so will improve your accuracy in chromatographic testing.

Selecting the right autosampler vial is crucial for ensuring the accuracy and reliability of your experimental results：5 Points Need to Consider When Choosing An Autosampler Vial.

Types of HPLC Vials

  We can classify sample vials by their material, bottle mouth, and internal structure. Different types of sample vials are suitable for different tests.

Material
  Before understanding the material, let's first understand the linear expansion coefficient. The expansion coefficient is the change in length for each degree of temperature. A lower expansion coefficient means that the glass can withstand more temperature change. In a word, it is: the ability of glass to withstand drastic temperature changes. USP (United States Pharmacopeia) customizes the classification of lab glass. It's based on its water resistance.

  We know the linear expansion coefficient of glass. So, the choice of material for sample vials is simple.

  1. USP Type 1, Class A 33 borosilicate glass is a chemically inert glass. It is widely used in laboratories, especially for chromatography. Class I glass is primarily composed of silicon and oxygen, with trace amounts of boron and sodium. It has low solubility and a linear expansion coefficient of 33.

  2. USP Type 1, Class B 51 glass is mostly silicon and oxygen. It has small amounts of boron, sodium, and more alkali metals than Class A glass. Yet, it can still meet laboratory needs.The coefficient of linear expansion is 51.

  3. Silanized or deactivated glass is one type of borosilicate glass. It has been made inert by coating its surface with organic silanes. Very hydrophobic and inert is the glass's surface. It is effective for long-term sample storage, pH-sensitive compounds, and trace analysis.

  4. USP Type and NP sodium-calcium glass are less chemically resistant. They are less resistant than borosilicate glass.

  5. Polypropylene (PP) material.

Bottle mouth type
  1. Clamp mouth 2. Bayonet mouth 3. Thread mouth

Body color of a vials
   Clear or Amber

Considerations for choosing HPLC Vials

Adaptability
  After you understand the material of the sample glass vial, we'll talk about its adaptability.The compatibility of the analyte and solvent must be taken into account when selecting a sample vial.There are a few typical sample properties that correspond to sample vial usage patterns.

  1. Use brown sample jars for light-sensitive samples. Brown samples in vials can effectively obscure light and prevent photoreactions.

  2. Strongly polar samples are easily absorbed by glass, hence utilize deactivated sample jars.

  3. For trace sample detection, use inner tubes. You can also use self-provided fixed inner tubes, or high-recovery sample vials. These are for conventional samples with small volumes.

  4. In ion analysis, use sample vials made of polypropylene (PP), not glass sample vials.

Choose according to sample volume

  To detect trace samples, we need to use micro vials. They make the test results accurate. The following are vials suitable for samples of various specifications.

  1. Sample volume less than 2ml
The vials come in many types. There are microsample vials (15µL-800µL) and high recovery sample vials (30µL-1.5mL). There are also inner tubes (100µL-400µL). There are also 250µL polypropylene microsample vials. There are also sample vials with built-in inner tubes (250µL-300µL).

  2.2mL sample volume
Glass sample vials, polypropylene sample vials.
 
  3. Sample volume greater than 2mL
4mL sample vials, headspace sample vials, test tubes, etc.

Understanding the different types of vials used in High-Performance Liquid Chromatography (HPLC).  Dive into this resource to learn more about selecting the best HPLC vials for your specific needs：Encyclopedia of HPLC vials

Choose according to closing method

  Threaded mouth vials are usually good for LC and LC/MS applications. They are low-evaporation and reusable. Compared with the crimp cap, this closing method is less harmful to the hands and needs no extra tools. Screw-on sample vial caps are available in both perforated caps designed for autosamplers and solid caps designed for sample storage.

  Crimp: Special tools are required for capping. They create a secure seal for extended storage periods when clamped right. Crimp-cap sample vials are suitable for GC and GC/MS applications. Since the crimp caps are not reusable, they provide higher security for food, forensics, and other applications where sample fraud is desired. If volatile compounds are analyzed, crimp-cap sample vials are recommended.

  Snap Top Caps: The sealing effect of the bayonet is not as good as the other two sealing methods. The bayonet cap sample vial cannot be pressurized, and the plastic bayonet cap can be covered without any tools, which is very convenient.

  Use a PE bottle stopper for sealing. Its resistance to corrosion and sealing are satisfactory. It is inexpensive and easy to use, but it requires few autosamplers to function.

Selecting the appropriate cap for your chromatography vials is essential for ensuring sample integrity and achieving accurate analytical results. Here’s a guide to help you choose the right cap for your chromatography vials：How to Choose the Right Cap for Your Chromatography Vials?