Overview
Selecting the proper sample container is an important consideration during elemental analysis. The choice of vial material can influence background contamination, analyte recovery, and overall data quality, particularly when working at trace and ultra-trace concentration levels.
Whether RSA™ Autosampler Vials are suitable depends largely on the analytical technique, sample preparation procedure, and elemental detection limits required by the method.
Considerations for ICP-MS Analysis
Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is one of the most sensitive elemental analysis techniques available.
Because of this sensitivity, even very small amounts of elemental extractables originating from laboratory containers may be detected during analysis.
In some ICP-MS applications, sample preparations contain:
- Hydrofluoric acid (HF)
- Strong mineral acids
- Aggressive digestion reagents
Under these conditions, glass containers should not be used because hydrofluoric acid attacks silica-based materials.
For many ICP-MS workflows, laboratories commonly use:
- Polypropylene containers
- PTFE containers
- Fluoropolymer labware
These materials are often selected because of their low elemental background and chemical resistance.
Glass Extractables and Elemental Analysis
All borosilicate glass containers can release trace amounts of certain elements.
Common glass-derived extractables may include:
- Sodium (Na)
- Boron (B)
- Silicon (Si)
Additional elements may be present at trace levels depending on the glass composition and analytical sensitivity.
For ultra-trace elemental analysis, these background contributions may become significant.
How RSA™ Vials Differ
RSA™ (Reduced Surface Activity) Autosampler Vials are manufactured to minimize extractable levels compared to conventional autosampler vials.
In particular, RSA™ vials provide substantially reduced levels of:
- Sodium
- Boron
This reduction can be beneficial in analytical applications where minimizing glass surface activity and extractables is important.
However, the reduced extractables of RSA™ vials may still not be sufficient for every elemental analysis application, particularly those involving ultra-trace quantitation by ICP-MS.
HPLC-ICP-MS Applications
Elemental analysis is not always performed using stand-alone ICP-MS techniques.
Increasingly, laboratories utilize hyphenated techniques such as HPLC-ICP-MS to analyze specific molecular forms of elements rather than total elemental content.
Examples include:
- Metal speciation studies
- Environmental analyses
- Pharmaceutical analyses
- Biological sample characterization
In these applications, the analytical objective is often to identify and quantify a specific chemical species containing the element of interest.
Example: Methylmercury Analysis
One common example is the determination of methylmercury in biological or environmental samples.
HPLC separation is used to isolate individual mercury-containing compounds prior to ICP-MS detection.
In these types of workflows, container selection remains important, but suitability depends on the complete analytical method and validation requirements.
Choosing the Appropriate Container
The most appropriate sample container should be selected based on:
- Analytical technique
- Detection limits
- Sample matrix
- Sample preparation conditions
- Regulatory requirements
- Validation criteria
Laboratories performing elemental analysis should evaluate container suitability during method development and validation.
Key Takeaways
- The suitability of RSA™ vials depends on the elemental analysis technique being used.
- Hydrofluoric acid sample preparations should not be stored in glass containers.
- Polypropylene and fluoropolymer containers are commonly used for ICP-MS applications.
- RSA™ vials contain significantly lower sodium and boron extractables than conventional glass vials.
- HPLC-ICP-MS methods may have different container requirements than traditional ICP-MS methods.
- Container suitability should be verified during method development and validation.
