We explored appropriate technical setups for the detection of volatile organic compounds (VOCs)
from exhaled cow breath by comparing six different polymer-based solid-phase extraction (SPE)
cartridges currently on the market for gas chromatography/mass spectrometry (GC-MS)
screening. Exhaled breath was sampled at a single timepoint from five lactating dairy cows using six
different SPE cartridges (Bond Elut ENV (ENV); Chromabond HRX (HRX); Chromabond HRP
(HRP); Chromabond HLB (HLB); Chromabond HR-XCW (XCW) and Chromabond HR-XAW
(XAW)). The trapped VOCs were analyzed by dynamic headspace vacuum in-tube extraction
GC-MS (DHS-V-ITEX-GC-MS). Depending on the SPE cartridge, we detected 1174–1312 VOCs
per cartridge. Most VOCs were alkenes, alkanes, esters, ketones, alcohols, aldehydes, amines,
nitriles, ethers, amides, carboxylic acids, alkynes, azoles, terpenes, pyridines, or sulfur-containing
compounds. The six SPE cartridges differed in their specificity for the chemical compounds, with
the XAW cartridge showing the best specificity for ketones. The greatest differences between the
tested SPE cartridges appeared in the detection of specific VOCs. In total, 176 different VOCs were
detected with a match factor >80%. The greatest number of specific VOCs was captured by XAW
(149), followed by ENV (118), HLB (117), HRP (115), HRX (114), and XCW (114). We conclude
that the tested SPE cartridges are suitable for VOC sampling from exhaled cow breath, but the SPE
cartridge choice enormously affects the detected chemical groups and the number of detected
VOCs. Therefore, an appropriate SPE adsorbent cartridge should be selected according to our
proposed inclusion criteria. For targeted metabolomics approaches, the SPE cartridge choice
depends on the VOCs or chemical compound groups of interest based on our provided VOC list.
For untargeted approaches without information on the animals’ metabolic condition, we suggest
using multi-sorbent SPE cartridges or multiple cartridges per animal.