Introduction

Temperature is an important factor when selecting autosampler vials and caps for analytical workflows. Whether samples are stored under refrigerated conditions, analyzed at elevated temperatures, or used in demanding laboratory environments, the thermal capabilities of both the vial and closure system should be considered.  Proper vial selection helps maintain:

• Sample integrity
• Analytical accuracy
• Instrument reliability
• Laboratory safety
• Consistent chromatographic performance

Understanding the thermal limitations of vial materials can help prevent sample loss, vial failure, and unexpected analytical results.

Standard Autosampler Vials

Most autosampler vials used in HPLC, UHPLC, GC, LC-MS, and related analytical applications are manufactured from high-quality borosilicate glass.  These vials are designed to operate reliably within the temperature ranges encountered in conventional autosampler operation.  Under normal laboratory conditions, standard autosampler vial temperatures rarely approach the thermal limits of borosilicate glass.  As a result, standard borosilicate autosampler vials are suitable for the vast majority of analytical applications.

High-Temperature Capability

Borosilicate glass exhibits excellent thermal resistance and can generally tolerate temperatures approaching:  300°C .  However, the actual usable temperature limit depends on several factors beyond the glass itself, including:

• Sample composition
• Solvent volatility
• Internal pressure development
• Cap and septa materials
• Heating rates
• Cooling rates
• Thermal shock conditions

For applications operating near elevated temperature limits, laboratories should evaluate the complete vial-cap-septa system rather than relying solely on the glass specification.

Recommended Practice

Before implementing routine high-temperature procedures, evaluate representative samples under actual operating conditions to confirm satisfactory performance.  This is particularly important for:

• Elevated temperature sample preparation
• Thermal stability studies
• Heated autosampler applications
• Chemical reaction monitoring

RSA™ Vial Temperature Limitations

RSA™ brand vials have specific temperature limitations that differ from conventional borosilicate autosampler vials.

Important Limitation

RSA™ vials should not be used above 120°C.

Exceeding this temperature may increase the risk of:

• Structural weakening
• Surface texture changes
• Stress-related damage
• Reduced vial integrity

Laboratories should observe this limit regardless of the operating capability of other borosilicate vial products.

For RSA™ product specifications, images, and ordering information, see:  RSA™ Glass Vials Product Information and Ordering Resources

Low-Temperature Considerations

While standard autosampler vials perform well under typical refrigerated conditions, they are not designed for cryogenic storage applications.

Temperatures approaching:  -80°C  present unique stresses to glass containers and closure systems.  Standard autosampler vials are therefore not recommended for long-term cryogenic storage.

Cryogenic Applications

Applications requiring storage near -80°C or lower should utilize containers specifically designed and validated for cryogenic use.  MICROSOLV does not currently offer cryogenic storage vials.

Clear vs. Amber Glass at Extreme Temperatures

Although both clear and amber autosampler vials are commonly used in analytical laboratories, neither is recommended for cryogenic applications.  For extremely low-temperature storage, amber glass may be less suitable than clear glass due to the additional stresses associated with the coloration process and material characteristics.  For cryogenic storage requirements, use purpose-built cryogenic containers rather than conventional autosampler vials.

Cap and Septa Considerations

Temperature limitations are often determined by the closure system rather than the vial itself.  When evaluating temperature compatibility, consider:

• Septa material
• Cap material
• Solvent exposure
• Sample pressure
• Exposure duration

The cap and septa should always be verified for compatibility with the intended operating temperature.

Recommended Best Practices

When selecting autosampler vials for temperature-sensitive applications:

• Verify temperature limits for both vials and caps.
• Test representative samples under actual conditions.
• Avoid using standard autosampler vials for cryogenic storage.
• Observe the 120°C maximum temperature for RSA™ vials.
• Consider both thermal and chemical compatibility.
• Inspect vials after exposure to elevated temperatures.

Following these practices can help improve safety, preserve sample integrity, and maintain reliable analytical performance.

Key Takeaways

• Standard borosilicate autosampler vials generally tolerate temperatures up to approximately 300°C.
• Actual performance depends on the total vial, cap, septa, solvent, and sample system.
• Standard autosampler vials are not recommended for storage near -80°C.
• RSA™ vials should not be used above 120°C.
• Cryogenic applications require specialized cryo-rated containers.
• Temperature compatibility should always be verified for both the vial and closure components.