posted on 2024-02-06, 17:04authored byG. Asher Newsome, Erin R. Birdsall, Robert B. Cody
New analytical functionality is demonstrated with an
enclosed interface
that joins a solid phase microextraction (SPME) device, a direct analysis
in real time (DART) probe, and a high-resolution mass spectrometer.
With a single 20 mm long SPME Arrow, the interface is able to perform
five discrete DART analyses on different areas of the same fiber in
1 min of practical operation time. Three-fiber replicates for 15 runs
total produce 15% or better center of variance (CV) values for both
volatile headspace sampling and direct immersion sampling of a solvated
analyte. Chemometric analysis of rapidly acquired headspace data is
able to distinguish volatile profiles. Selective desorption within
the interface also confers the ability to selectively sample to discrete
areas of a fiber, and three different headspace samples or five different
liquid samples can be acquired and differentiated with one Arrow.
A five-point standard addition curve is constructed to measure the
concentration of the solvated analyte. Unmodified commercial components
of the analysis system include the fiber itself, the Orbitrap and
AccuTOF mass spectrometer platforms, and the conditioning gas chromatograph
inlet. Machine diagrams for the SPME-DART interface and Arrow fiber
holder are included.