Portable Liquid Chromatography Mass Spectrometry (P-LCMS)
By Dr. Matthew Askeland
Due to the wide-ranging uses and properties of PFAS, contamination impacts can be present in remote regions, while covering large areas that may be difficult to access. This can be challenging when sampling soil, groundwater or other environmental media, due to holding times and associated transit times to get samples to the laboratory. This is particularly the case for a large country like Australia, where contaminated sites can be great distances from even small regional airports. While increasing costs, this also presents a threat to sample integrity and data quality.
The persistence and solubility of PFAS means that soil and water impacts can extend great distances, making contamination delineation and source tracking challenging. In these cases, dynamic sampling programs are usually required, with the last set of results informing new sample point locations. This becomes difficult, costly and time-consuming when turnaround times for results can be greater than one week. These limitations can also apply to PFAS stabilisation programs, when rapid results are required to prove the efficacy of treatment so that materials can continue pass through the train.
ADE’s newly developed and patented proprietary technology Portable Liquid Chromatography Mass Spectrometry (P-LCMS), developed in partnership with Trajan Scientific, is a groundbreaking technique that enables us to bring a compact laboratory to the field, capable of detecting and quantifying PFAS in soil and water.
Some typical applications include the rapid, dynamic delineation of PFAS soil hotspots or groundwater plumes, tracking PFAS sources or assessing PFAS mass flux and surges on a temporal basis through drainage systems or surface water. The method employs a miniaturised LCMS which is mounted in a specialised small vehicle and is supported by a robust standard analysis procedure to assist in the collection of reliable PFAS analytical data.
The system has been specially designed to be able to deal with high PFAS concentrations, as well as detect to an LOR ranging 1-10 µg/kg in soil. The system has the capability to provide same day results, with the analysis of between 30 and 60 samples achievable per day depending on the sample matrix.
Application and Benefits
This unique and innovative tool is designed for a wide range of applications, unlocking several previously unavailable capabilities including:
Remote PFAS investigations
Capacity to support works in locations where sample holding times or transport of samples offsite is prohibitive to the project.
Emergency response Deployable rapid response to sites where quick results is required to effectively identify and mitigate risks.
Large volume or tight program projects
Capacity to have a fast 1-day turn around on analytical results for projects with a large sample volume or short program, where analysis on site reduces analytical results reporting latency based on sample transport.
Cost effective delineation and screening
Provides an effective investigatory tool, particularly for large sites, to assist in on site decision making, screening programmes and the delineation of PFAS hot spots.
Treatment train QA/QC or validation
Employed as an ideal tool for inclusion on site during treatment process or plant commissioning, QA/QC or validation, as the system can provide quick analytical results to inform success, or non-conformities in the process for corrective action.
Provides the unique ability to track PFAS sources in near-real-time, particularly useful in waterways, pipes, and watercourses with potential pulse PFAS mass flows (i.e., stormwater and drainage).
In September 2023, ADE deployed its P-LCMS system to an aviation facility to assess potential PFAS impacts across a variety of features on the site, these included a large open paddock (to be developed as part of an upcoming runway extension), soil stockpiles, and an evaporation basin.
Key environmental works included the assessment of the open paddock area. The goal of sampling within the paddock site was to quickly identify contamination across the proposed works area and identify any potential soil PFAS hotspots, considering the bulk of the area was considered to have relatively minor PFAS impacts. To achieve this, an initial grid of nine samples was laid out across the site, and samples collected and submitted by the field team to the mobile lab for P-LCMS analysis.
Results from the initial sampling round were supplied to the field team before midday (alongside stockpile data), and one sample location with elevated PFAS concentration was identified. A further eight samples were taken around the original sample location (four samples in cardinal directions 2 m and 8 m from the original location) and were submitted for analysis. These samples were analysed onsite and demonstrated the extent of the hotspot within the same working day. This approach now enables decision making regarding appropriateness of the site for proposed future uses. The work demonstrated that P-LCMS not only allows for fast results on site, but for real-time decision making and delineation to provide the highest value targeted data to inform decision making.
In addition to the above, it was demonstrated via sampling at the paddock andevaporation pond locationthat the system could handle both trace PFAS concentrations (<100 ug/kg) like those in the paddock,as well as very high PFAS concentrations (>1000mg/kg) based on the sampling conducted in the fire training sites evaporation pond. Stockpile sampling also demonstrated that the PFAS-impacted material being stockpiled in this area did not in fact contain PFAS, and as such was acquired from an area that was poorly delineated. This data could then be used to rectify the handling of this material, demonstrating both the value of P-LCMS as a delineation tool, but also for reactive testing and management of PFAS impacted spoils as they are generated.
P-LCMS brings a new approach to PFAS investigations, remediation treatment QA/QC and validation, by allowing the user more control and the ability to be better informed while on site. For the first time, site investigations can make use of near-real-time data to inform sampling locations or treatment processes during works to maximise the value of analytical data being collected on a given project. This not only has significant budget and timeline implications but equips the client with the best available data to decision make and brings greater certainty to the finding of investigation, quality control or validation activities.