气相色谱-质谱法
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Gas Chromatography-Mass Spectrometry (GC-MS)
GC-MS combines two powerful techniques to identify compounds with low detection limits and enable potential quantitative analysis. It is well-suited for analyzing liquid, gas, and solid samples, though the target compounds are typically volatile or semi-volatile.
GC-MS is part of our Smart Chart Series. Additionally, it can separate complex mixtures of compounds for identification and quantification.
How GC-MS Works
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Gas Chromatography (GC) Step:
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The sample is vaporized and carried by an inert gas through a coated glass capillary column.
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The "stationary phase" is bonded to the column’s interior.
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Retention time is the duration a compound takes to travel through the column to the detector.
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Compounds are identified by comparing their retention times to reference standards.
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Mass Spectrometry (MS) Step:
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Compounds eluting from the GC column are fragmented via electron impact ionization.
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Charged fragments are detected, and the resulting mass spectra are used for molecular identification.
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The fragmentation pattern is reproducible and enables quantitative measurements.
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Sample Compatibility
GC-MS analyzes liquids, gases, and solids:
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Liquids/Gases: Typically injected directly into the GC.
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Solids: Require solvent extraction, outgassing (thermal desorption), or pyrolysis.
Specialized Sampling Techniques:
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Thermal Desorption:
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Conducted under helium flow at controlled temperatures (40–300°C).
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Analytes are collected on a cryogenic trap during desorption.
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Sample chamber dimensions: 1.25" × 4" cylinder.
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Pyrolysis:
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Used for materials incompatible with direct GC-MS injection.
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Samples are heated (up to 1400°C) to decompose molecules reproducibly.
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Smaller resulting fragments are analyzed by GC-MS.
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Other Sample Prep Methods:
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Derivatization
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Static headspace analysis
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Purge-and-trap
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SPME (Solid-Phase Microextraction)
Selected based on sample type and target species.
Ideal Applications
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Identification/quantification of volatile organic compounds (VOCs) in mixtures
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Outgassing studies
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Residual solvent testing
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Trace impurity detection in liquids/gases
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Extractables assessment in plastics
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Contaminant analysis on semiconductor wafers (via thermal desorption)
Strengths
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Separation and identification of organic components in complex mixtures
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Quantitative analysis
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Trace organic contaminant detection:
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Liquids: Mid- to low-ppb levels
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Solids: Nanogram-level sensitivity (dynamic headspace)
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Limitations
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Target compounds must be volatile or derivatizable.
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Non-volatile matrices (wafers, oils, metals) require extraction/outgassing prep.
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Challenging for atmospheric gases (CO₂, N₂, O₂, Ar, CO, H₂O).
Technical Specifications
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Detected signals: Molecular ions and characteristic fragment ions
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Mass range: Up to *m/z* 800
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Detection limit: ~1 ng introduced to the column
Why Choose EAG?
We provide GC-MS services for diverse materials, delivering:
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Fast turnaround times
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Accurate data
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Personalized support to ensure actionable insights
Next Step: Complete the form to consult our experts on how GC-MS can analyze your materials.