GC-MS Tuning Solutions, Internal and Surrogate Standards

By: Jim Walbridge and Kathy Kiefer, Reporter US Vol 28

Because of its sensitivity and specificity, GC-MS is a widely used technique in environmental and forensic chemistry. Some important applications within these markets include many EPA methods, drugs of abuse monitoring and fire and explosives residue investigations. To get the most out of your GC-MS analysis, it is important to choose the proper internal standards, surrogates and tuning solutions, like those offered by Sigma-Aldrich under its Supelco brand.

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Tuning Solutions

Tuning solutions are utilized to “tune” or optimize MS detector parameters. This maximizes the accuracy of mass and ion abundance measurements. Some tuning solutions also contain compounds used to assess injection port inertness and GC column performance. Our tuning solutions are formulated as specified in particular EPA methods and are important tools for the qualification of GC-MS systems.

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Internal Standards

GC-MS protocols typically utilize the internal standard method of quantification. Internal standards gauge the method’s ability to extract target analytes from the sample matrix, and are used to monitor and adjust instrument fluctuations. Pentafluorobenzene, 1,4-difluorobenzene, 1,4-dichlorobenzene-d4 and chlorobenzene-d5 are examples of internal standards.

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Surrogate Standards

Surrogate standards are used to monitor the entire analytical process from sample preparation to instrument performance. Toluene-d8, 4-bromofluorobenzene and dibromofluorobenzene are examples of surrogate standards.

The table below lists a sample of the many GC-MS standards and tuning solutions available from Sigma- Aldrich. A Certificate of Analysis is supplied with each product. The single and multi-component solutions are certified for identity, purity and concentration. Each component is guaranteed to be within +/-0.5% of the stated concentration.

To view our complete offering of GC-MS standards,

please visit sigma-aldrich.com/standards.

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