# Headspace Injection Method for Intermittent Sampling and Profiling Analyses of Volatile Organic Compounds Using Dielectric Barrier Discharge Ionization (DBDI)

## TL;DR

A new headspace injection method using DBDI-MS enables efficient and automated analysis of volatile organic compounds in complex samples.

## Contribution

A cost-effective, automated headspace injection method for VOC analysis using DBDI-MS is introduced and optimized.

## Key findings

- The method achieves detection limits in the high nanomolar to low micromolar range for various VOCs.
- Key parameters like vial volume and incubation temperature were optimized to improve signal intensity and repeatability.
- The method was successfully applied to monitor ethanol production and profile biofluids after asparagus consumption.

## Abstract

A direct headspace injection method is presented and
optimized
for the analysis of volatile organic compounds (VOCs) using dielectric
barrier discharge ionization-mass spectrometry (DBDI-MS), incorporating
an intermediate vial in which the sample headspace is injected. The
setup is built of commonly available, cheap consumable parts and easily
enables the incorporation of different gases for generating different
ionization atmospheres. The method can be fully automated by using
standard GC autosamplers, and its rapid analysis time is suitable
for high-throughput applications. We show that this method is suitable
for both profiling analysis of complex samples such as biofluids
and quantitative measurements for real-time reaction monitoring. Our
optimized method demonstrated improved reproducibility and sensitivity,
with detection limits for compounds tested in the high nanomolar to
the low micromolar range, depending on the compound. Key parameters
for method optimization were identified such as sample vial volume,
headspace-to-liquid ratio, incubation temperature, and equilibration
time. These settings were systematically evaluated to maximize the
signal intensity and improve repeatability between measurements. Two
use cases are demonstrated: (i) quantitative measurement of ethanol
production by a metal–organic framework from CO2 and (ii) profiling of biofluids following the consumption of asparagus.