Application · Environmental analysis

Headspace, SPME and SPDE compared

Whether water, soil or air: reliable analytical results begin with suitable sample preparation. Headspace, SPME and SPDE offer different ways to sample and enrich organic trace compounds. This comparison helps you choose a technique for your target compounds and shows how eTrap and SMM complement the workflow.

HeadspacePAL3 with headspace incubator

SPMECTC SPME Arrow

SPDESPDE – The Magic Needle

Comparison of enrichment, compound groups and combinations with eTrap and SMM
Criterion	Static headspace	SPME Arrow	SPDE
Principle	Sample the headspace above the temperature-controlled sample.	Collect compounds on a coated fiber or SPME Arrow.	Repeatedly draw the sample through an internally coated needle.
Enrichment	Without eTrap: no. With eTrap: yes, including multiple injections.	Yes, on the fiber/Arrow coating.	Yes, on the needle coating.
Compound groups	Primarily VOCs.	VOCs and SVOCs, depending on coating and method.	VOCs and SVOCs, depending on coating and method.
Sample contact	Headspace.	Headspace or direct immersion in liquid.	Headspace or liquid.
GC introduction	Gas injection.	Thermal desorption in the inlet.	Thermal desorption with carrier-gas flushing in the inlet.
eTrap particularly beneficial for	Highly volatile VOCs: splitless introduction and sharp focusing.	Volatile to highly volatile VOCs: focusing after desorption.	Volatile to highly volatile VOCs: focusing after desorption.
Additional benefit with eTrap	Collect multiple aliquots from the same incubated sample and release them together.	Transfer a narrow sample band to the column.	Transfer a narrow sample band to the column.
Chromtech SMM	Stirring and temperature control of the sample.	Stirring instead of shaking: protects SPME fibers and reduces the risk of breakage.	Controlled stirring and temperature control support extraction.

VOC (Volatile Organic Compounds): volatile organic compounds. SVOC (Semi-Volatile Organic Compounds): semi-volatile organic compounds.

SPME means solid-phase microextraction; SPDE means solid-phase dynamic extraction. Both use solvent-free extraction. SPME Arrow also uses this enrichment principle.

The eTrap is particularly beneficial for highly volatile VOCs such as vinyl chloride, chloroethane and MTBE. Its usable range depends on trap version, sorbent, temperature and method. This focusing benefit is usually less prominent for SVOCs.

The SMM stirs with a magnetic stir bar while the sample vial remains stationary. This particularly protects immersed SPME fibers and reduces the risk of breakage. Coating, matrix and extraction conditions determine the suitability of each technique.