Pyrolysis Gas Chromatography the easy way

Pyrolysis is the breaking apart of chemical bonds by thermal energy, with the production of smaller, more volatile components. Analytical pyrolysis is used to introduce certain sample types to a gas chromatograph, which can only handle compounds in the semi-volatile range. These sample types include solids and high molecular-weight compounds. Pyrolysis is also used to minimize sample preparation, or when analysis of a whole sample is desired. Applications for pyrolysis include forensics, paints, ink, art materials, polymers, adhesives, surfactants, and even microorganisms.One of the benefits of pyrolysis is that sample preparation is usually minimal, consisting of trimming and weighing solid samples into a quartz tube or micro vial. Or, liquid samples can be delivered onto a probe or micro vial using a microliter syringe. In both cases, the sample capacity is in the microgram or low milligram range.

Introduction

With OPTIC Multi Mode Inlet Pyrolysis GCMS is simple cheap and easy.

Introduction OPTIC for Pyrolysis

Cut a small piece from the samplePut sample in the micro vialWeighing the samplePlace micro vial in linerPlace liner in the OPTIC inletRun the sample

Solid sample

Placing the liner can also be automated with LINEX.

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Sample: 1.0 mg of solid polymer OPTIC methodMethod Type SplitEnd Time 44:19 mm:ssInitial Temperature 50 °CRamp Rate 60 °C /sFinal Temperature 600 °CTransfer Time 03:00 mm:ssTransfer Column Flow 1.0 ml/minStart Column Flow 1.0 ml/minEnd Column Flow 1.0 ml/minSplit Flow 250 ml/minSave Split Flow 50 ml/min

Pyrolysis Solid Polymer

Liquid sampleA liquid sample for pyrolysis can be handled like a “normal” liquid injection. Even Large Volume Injection Pyrolysis is possible. Because the injections are done with a micro syringe it is possible to perform quantitative pyrolysis with the OPTIC inlet.

The patented direct heating technology of the OPTIC makes it possible to heat very fast to a high end temperature.

- Liquid injection is done at low temperature- Solvent is vented away via the split line- Inlet is heated with fast ramp rate

Pyrolysis liquid injection, sample in DCM

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1 µl injection, sample in DCM

3,7 min dimethylsiloxane trimer6.2 min phenol6.3 min octamethylcyclotetrasiloxane7.7 min 4-methyl-phenol8.7 min dimethylsiloxane pentamer 19.8 min BPA

Linearity of Py-GC-MS for PMMA and PS

Range: 160 µg/ml to 0 µg/mlCorr. R: 0.9992

Polystyrene and PMMA blend 1µl injection

Range: 170 µg/ml to 0 µg/mlCorr. R: 0.9990

styrene (m/z 104) PMMA (m/z 100)

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Pyrolysis liquid injection

An optional cryogenic trap is available with rapid cooling and efficient re-heating, ensuring reproducibility and optimum peak shape. Cryo-focusing is used to narrow the width of a peak, as a result the signal to noise ratio and the detection limit are improved.

Cold Trap for refocussing of volatiles

For more information about the cryo trap see this presentation.

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Visit www.glsciences.eu for more information.