Butterworth Laboratories offers specialized Multiple Headspace Extraction (MHE) Gas Chromatography services to accurately quantify volatile compounds in solid samples, particularly when traditional calibration methods are inadequate.
Understanding MHE Gas Chromatography
MHE is a calibration technique designed for insoluble solid samples, making standard calibration approaches challenging. It involves repeated headspace sampling of a single sample vial, allowing for the exhaustive extraction and quantification of volatile analytes. This method is especially useful when dealing with materials where complete solvent extraction isn’t feasible.
Applications of MHE
One notable application of MHE is in analysing Medical Devices, which are often sterilized using ethylene oxide (EO). ISO 10993-7 mandates the determination of EO residues to ensure patient safety. Traditional methods involve time-consuming extended water extractions. MHE offers a more efficient alternative by enabling rapid and accurate quantification of residual EO in these medical devices.
Our Expertise
With nearly five decades of experience in contract analytical services, we are equipped with state-of-the-art technology and a team of laboratory analysts proficient in MHE Gas Chromatography. Our commitment to quality and precision ensures we deliver reliable results tailored to our client’s needs.
For a more in-depth understanding of MHE and its applications, we invite you to download our comprehensive white paper authored by our Consultant Chemist, Frank Judge.
Please use our General Enquiry Form to discuss how our MHE Gas Chromatography services can support your analytical requirements.
For a full overview of our analytical techniques, visit our Techniques page.
Frequently Asked Questions
MHE-GC is preferred when:
Insoluble samples: where traditional solvent extraction is problematic and samples are highly insoluble.
Analysis of complex samples, such as polystyrene, polymethyl methacrylate, and other polymeric materials/plastics
MHE technique is used to quantify samples in a complex matrix or solid without matrix corresponding to the calibration standards. The standard is analysed, without matrix, in a total evaporation headspace with MHE, determining a response factor. The natural logarithm peak areas obtained from each injection are plotted against the extraction cycle number. This plot is typically a decaying curve. The calibration curve is then used to quantify analytes in the sample.
The analyte partitions between the sample and headspace consistently.
There are no losses due to degradation or leaks, not involving the venting after each extraction.
Usually, 3 to 5 sequential extractions are sufficient. The number depends on how rapidly the analyte is depleted. Fewer extractions can be used if the decay of signal is well-characterised and fits the expected model.
