ANALYTICAL INFORMATION
Material Identification - The first result from the compiled data is a total-ion chromatogram (TIC), which is a plot of the total mass eluting from the GC and detected by MS as a function of time. Each
peak or band in the chromatogram represents a discrete chemical compound, or a mixture of compounds with identical retention times. The retention times in the chromatogram provide the first
indication of the sample constituents. More specific identification of the compound(s) for each band can then be made from the mass spectrum corresponding to the band. Compounds are identified from the mass spectrum by their unique ion fragmentation patterns. This compound identification analysis is performed by a computerized comparison of the mass spectra for the sample with spectra library for known compounds.
Quantitation - The analysis results can be quantified using the data from the chromatogram. The area under each peak in the chromatogram is proportional to the concentration of the compounds represented by that peak. The concentration for each compound in the sample is calculated from a standard curve of known concentrations established for that compound. The analysis sensitivity can be as low as a few nanograms.
TYPICAL APPLICATIONS
• Identification of foreign material contamination
• Analysis of outgassing products for disk drive components
• Identification of polymer additives
• Analysis of polymer cure by-products
SAMPLE REQUIREMENTS
The samples for GC/MS can be gases, liquids, or solids. However, only those constituents that are gaseous and stable at the analysis temperature can be analyzed. Gases and liquids can be injected directly into the sample injector. Volatile compounds from solid materials are collected using a headspace sampler. The sample from a headspace attachment can be collected and injected at one time (static headspace), or the sample can be collected and analyzed continuously over a set time period (dynamic headspace).
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