Introducing mass spectrometers for groundwater studies

Groundwater studies increasingly depend on dissolved-gas tracers to quantify subsurface processes and to support defensible interpretation of aquifer behaviour. Mass spectrometry enables rapid, high-sensitivity measurement of dissolved noble gases (e.g., He, Ar) and reactive gases (e.g., CH₄) that act as key indicators for assessing groundwater age, recharge elevations, and flow paths without waiting on slow sampling-to-lab turnaround.

A core advantage is real-time detection of transient events during sampling and monitoring. By providing results in under a minute, dissolved-gas mass spectrometry can capture dynamic changes that may be missed with conventional workflows and helps teams make faster, more confident decisions at the point of measurement.

Hiden Analytical supports groundwater dissolved-species workflows with both portable and bench-top compact mass spectrometer platforms:

pQA – Portable Quadrupole Analyser

Configured for environmental measurements in the field, the pQA is offered with interchangeable sampling inlets, including MIMS inlets for dissolved species in groundwater and related matrices. This approach supports high-throughput field campaigns and can reduce long-term operational burden for large-scale studies.

For extended or remote deployments, the pQA can be powered from a 12 V supply and is supported for battery and/or solar-powered operation (as well as mains power for lab use).

HPR-40 MIMS – Compact bench-top analyser

The HPR-40 MIMS is a bench-top membrane inlet mass spectrometer designed to monitor gas species in liquids at sub-ppb levels (standard 200 amu mass range), supporting dissolved-gas applications where extremely low concentration monitoring is critical.

Dissolved-gas MS methods are also used to support excess N₂ determination using the N₂/Ar method for groundwater monitoring and denitrification assessment.