Applications
  • Identify and Quantify Solvent Systems in Adhesives and Coatings
  • Detect and Quantify Residual Monomer in Polymers
  • Detect Contamination in Food Stuffs
  • Detect Banned Performance Enhancing Chemicals in Racing Tires
  • Detect Accelerants in Fire Debris Samples
  • Detect Accelerants in Fire Debris Samples
  • Characterize Fragrances and Gas Blends

FAI's Teledyne Tekmar HT-3 DHC-GC-MS Autosampler Robot
Techniques>Chemical Analysis>Gas Chromatography-Mass Spectroscopy>Dynamic Headspace Concentration (DHC) GC-MS

Dynamic Headspace Concentration (DHC)

Gas Chromatography-Mass Spectroscopy


What is DHC-GC-MS?

Dynamic Headspace Concentration GC-MS is used to identify and quantify volatile and semi-volatile components in materials such as plastics, rubber, coatings, composites, lubricants, adhesives, cleaning chemicals, fragrances, cosmetics, and environmental samples. The phrase "Dynamic Headspace Concentration" simply refers to the sampling process described below. It was originally designed to look for trace levels of alcohol in blood. DHC-GC-MS is one of the most sensitive sampling techniques for identifying volatiles.

How It Works

DHC-GC-MS is particularly useful for analysis of materials that cannot be directly injected into the GC-MS system. Prior to analysis, the sample is placed in a 20mL glass vial with inert septum and heated (up to 300 ˚C). The vial is purged with a stream of helium which carries volatized compounds to a thermal desorption trap. Once the sample has been completely purged the trap is heated, sending the trapped compounds to the gas chromatograph for separation and mass spectrometer for analysis.


Equipment

FAI uses a Tekmar HT-3 Dynamic Headspace Concentration Autosampler which can robotically process up to 60 samples unattended. The GC-MS duties are performed by an HP/Agilent 5890 Series II Plus Gas Chromatograph with an HP 5989B Mass Engine Mass Spectrometer. This mass spectrometer can collect positive or negative ions, run electron impact or chemical ionization and can scan up to 1000 Daltons molecular weight or perform Selected Ion Monitoring (SIM) analysis.

20mL glass vials for Dynamic Headspace Concentration GC-MS

Samples

Samples for DHC-GC-MS range from a few milligrams to 10 grams depending on how much volatiles we expect to leave the sample.


Results

FAI provides you with a detailed report which includes chemical composition of gases/volatiles given off by the sample. A sample chromatogram is shown below.


DHC-GC-MS Chromatogram Example



Related Services:

Gas Chromatography Mass Spectroscopy (GC-MS)

Pyrolysis GC-MS (Py-GC-MS)

Liquid GC-MS (L-GC-MS)

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