One approach receiving increasing attention is PFAS Extraction using Milestone ETHOS X. Microwave-assisted extraction with the Milestone ETHOS X provides laboratories with an alternative approach to conventional shaker-table extraction while targeting improvements in sample throughput, handling, reproducibility and overall laboratory efficiency.

The Milestone application study evaluating the ETHOS X with the XTR-44 rotor demonstrates its application to the extraction of PFAS compounds from solid matrices under an EPA Method 1633A analytical workflow.

For environmental laboratories searching for PFAS extraction equipment, PFAS extraction using microwave technology, EPA 1633 PFAS sample preparation, microwave-assisted PFAS extraction, PFAS extraction from soil, PFAS extraction from sediment, PFAS extraction from biosolids, or Milestone ETHOS X PFAS extraction, the technology provides an important approach to modernizing the sample-preparation stage.

What Are PFAS?

PFAS stands for per- and polyfluoroalkyl substances, a broad family of synthetic fluorinated compounds.

Because PFAS analysis frequently involves very low concentrations and complex environmental matrices, sample preparation becomes one of the most important stages of the analytical process.

Environmental laboratories may need to analyze PFAS in matrices including:

• Soil

• Sediment

• Biosolids

• Wastewater-related materials

• Aqueous samples

• Tissue

• Other environmental samples

When solids such as soils and sediments are analyzed, the target compounds first need to be efficiently extracted from the matrix.

This makes PFAS extraction an essential stage before instrumental determination.

Why PFAS Sample Preparation Matters

Advanced LC-MS/MS instrumentation can provide highly sensitive measurements, but analytical performance still depends heavily on what happens before the sample reaches the instrument.

PFAS sample preparation can be time-consuming and labor-intensive.

The Milestone application report identifies sample preparation as a critical component of the complete PFAS analytical workflow because it can involve substantial manual handling and therefore introduce opportunities for errors.

Conventional extraction approaches can require repeated operations and transfers. Every additional manual step potentially increases analyst workload and complicates laboratory throughput.

For commercial environmental laboratories in particular, this becomes important because laboratories often have to balance:

analysis turnaround time,

availability of skilled personnel,

operating costs,

laboratory space,

sample volume,

quality requirements,

and regulatory requirements.

For these reasons, laboratories increasingly look for ways to simplify PFAS extraction from solid samples while maintaining analytical performance.

This is where PFAS Extraction using Milestone ETHOS X becomes relevant.

PFAS Extraction Using Milestone ETHOS X

The Milestone ETHOS X is a microwave extraction platform that can be configured for PFAS extraction using the XTR-44 rotor.

In the PFAS application evaluated by Milestone, the ETHOS X configuration included integrated magnetic stirring and disposable polypropylene extraction vessels.

The purpose of microwave-assisted extraction is to provide controlled energy to the extraction process while allowing multiple samples to be processed in a reproducible manner.

For PFAS laboratories, this approach can help reduce dependence on lengthy shaker-table extraction operations.

The application report specifically evaluates ETHOS X extraction for target PFAS compounds associated with EPA Method 1633A.

Understanding EPA Method 1633

EPA Method 1633 addresses analysis of PFAS in multiple matrices using LC-MS/MS.

The Milestone application report discusses EPA Method 1633 Revision A in relation to PFAS analysis in aqueous, solid, biosolid and tissue samples.

For laboratories processing solid matrices, sample extraction can represent a significant portion of the preparation time.

The application report describes the conventional shaker-table technique as involving multiple transfers between extractions, creating additional labor and potential sample-loss opportunities through repetitive handling.

An important point highlighted in the report is that EPA 1633 includes provisions regarding improvement of method parameters such as extraction methodologies under the relevant method requirements.

Laboratories must, of course, perform their own method validation and comply with applicable regulatory and quality-system requirements before implementing a modified extraction workflow.

Why Use Microwave-Assisted Extraction for PFAS?

Microwave-assisted extraction introduces controlled heating and mixing into sample preparation.

The broader value of microwave sample preparation can also be seen in other analytical applications.

Research summarized in Milestone’s microplastics white paper demonstrates how microwave-assisted preparation has been used to reduce lengthy sample-preparation procedures and provide efficient extraction from environmental matrices.

Although microplastic extraction and PFAS extraction are different analytical applications, these studies demonstrate the broader role microwave technology can play in improving analytical sample preparation.

For PFAS Extraction using Milestone ETHOS X, several practical advantages are especially important.

Faster Extraction

One of the strongest operational advantages described in the PFAS application report is extraction time.

Milestone reports up to a 70% reduction in extraction time compared with the conventional approach evaluated.

The ETHOS X microwave program used for the study consisted of:

Step 1: 5 minutes, up to 1000 W, 65°C
Step 2: 10 minutes, up to 1000 W, 65°C

This produces a programmed microwave extraction time of approximately 15 minutes.

For laboratories processing a high volume of environmental samples, reducing extraction from an hours-based workflow to a short controlled microwave program can have a significant effect on productivity.

High Sample Capacity with XTR-44

The XTR-44 rotor provides 44 positions.

Capacity is particularly relevant to commercial environmental laboratories because sample batches can arrive unpredictably and urgent samples may need rapid processing.

A higher-capacity extraction system can allow laboratories to process more samples in parallel rather than relying entirely on sequential manual preparation.

Therefore, searches such as:

“high throughput PFAS extraction”

“PFAS sample preparation equipment”

“PFAS extraction system”

“EPA 1633 sample preparation”

and

“PFAS extraction from soil”

all address an important laboratory requirement: increasing throughput without sacrificing analytical quality.

PFAS Extraction from Soil Using Milestone ETHOS X

Soil is one of the major matrices evaluated in the Milestone study.

Three different soil samples were prepared in triplicate to compare the EPA 1633 shaker-table approach with microwave extraction.

The study used approximately 5 g of sample on an as-received basis, while moisture content was determined according to the EPA 1633 guidance described in the application.

PFAS-free Ottawa sand was used for blank spikes and QC samples.

For the known PT soil sample, a smaller quantity was used according to the study protocol.

The samples and QC materials were placed into 50 mL disposable polypropylene centrifuge tubes.

A magnetic stir bar was introduced into the tubes.

Extracted internal standard was then added and allowed to sit according to the specified method procedure.

Following this stage, the extraction solvent was added.

Extraction Solvent

The application used:

15 mL of 0.3% ammoniacal methanol

for each sample/QC.

The tubes were capped and positioned inside the Milestone ETHOS X XTR-44 rotor.

QC samples were appropriately spiked with the target PFAS compounds.

The samples then underwent the controlled microwave extraction program.

This approach combines:

microwave energy,

controlled temperature,

defined extraction time,

integrated stirring,

and parallel sample processing.

Together, these characteristics create a standardized approach to PFAS extraction from soil using microwave-assisted extraction.

PFAS Extraction Workflow

A simplified workflow based on the evaluated application can be represented as:

Sample weighing → Internal standard addition → Extraction solvent addition → ETHOS X microwave extraction → Cooling → Centrifugation or filtration → Concentration → SPE → Internal standard addition → LC-MS/MS analysis

Each step plays an important role.

Step 1 – Sample Weighing

The study generally used approximately 5 g of solid sample.

Proper sample homogenization and representative sampling remain important because environmental matrices can be heterogeneous.

Step 2 – Addition of Internal Standard

Extracted internal standards were added to samples and QC materials.

The study allowed the material to sit for approximately 30 minutes according to the analytical workflow.

Step 3 – Addition of Ammoniacal Methanol

Approximately 15 mL of 0.3% ammoniacal methanol was used.

The extraction solvent interacts with the solid matrix and supports extraction of the target PFAS compounds.

Step 4 – Microwave Extraction

Samples were loaded into the XTR-44 rotor and processed in the ETHOS X.

The study used 65°C with a two-step microwave program totaling approximately 15 minutes.

Step 5 – Cooling

After microwave extraction, vessels were cooled.

The report states cooling took less than approximately five minutes before subsequent processing.

Step 6 – Centrifugation or Filtration

Samples could then be centrifuged at approximately 3000 rpm for 5–10 minutes.

The report also describes an alternative filtration workflow using the Milestone SFS-24 filtration system with preconditioned stacked filters.

This option can eliminate the centrifugation stage in the evaluated workflow.

Step 7 – Concentration

Extracts were concentrated using nitrogen evaporation to a volume below approximately 10 mL.

PFAS-free water was subsequently added.

Step 8 – Solid Phase Extraction

The extracts underwent solid phase extraction (SPE), resulting in a final volume of approximately 5 mL in the described application.

Step 9 – LC-MS/MS

Non-extracted internal standards were added before instrumental analysis.

The application study then analyzed the prepared extracts according to EPA 1633A using LC-MS/MS.

PART 2 – PFAS Extraction Using Milestone ETHOS X: Performance and Analytical Benefits

An extraction technique cannot be evaluated purely on speed.

For environmental PFAS laboratories, analytical quality is essential.

The important question is therefore not simply:

“Can microwave extraction extract PFAS quickly?”

It is:

“Can microwave-assisted PFAS extraction provide results comparable to an established extraction workflow?”

The Milestone application report investigated precisely this question.

Microwave Extraction vs Shaker Table Extraction

The study compared shaker-table extraction and microwave extraction across three soil samples.

Several important EPA 1633 PFAS target compounds were included in the dataset.

Among them were:

PFOS,

PFOA,

PFHxS,

PFHxA,

PFNA,

PFDA,

PFDoA,

PFHpA,

PFPeA,

PFPeS,

PFBS,

PFBA,

and numerous additional EPA 1633 target analytes.

For example, one sample showed PFOS results of approximately 21 µg/kg using shaker-table extraction and 20.7 µg/kg using microwave extraction.

For PFOA in the same sample, the values were approximately 3.6 µg/kg and 3.14 µg/kg, respectively.

Another sample showed PFOS at approximately 38 µg/kg using the shaker table and 34.5 µg/kg with microwave extraction.

A third sample showed approximately 53 µg/kg PFOS using shaker extraction and 57.7 µg/kg using microwave extraction.

These individual examples should not be interpreted as universal performance specifications, but they illustrate the comparability observed in the study.

Reference Material Evaluation

The report also provides extensive data from a reference/PT soil sample.

The microwave extraction results were compared with certified values and acceptance ranges.

The listed analytes included many compounds from the EPA 1633 target list.

For example:

PFOS had a certified value of approximately 21.5 µg/kg, while microwave extraction produced approximately 21.6 µg/kg.

PFHxS had a certified value of approximately 24.0 µg/kg, compared with approximately 26.6 µg/kg using the microwave workflow.

PFBS had a certified value of approximately 16.3 µg/kg, with approximately 19.7 µg/kg reported from microwave extraction.

PFDA had a certified value of approximately 12.4 µg/kg, while microwave extraction produced approximately 14.7 µg/kg.

The report states that the evaluated data were within the specified method requirements and acceptance criteria.

Advantages of PFAS Extraction Using Milestone ETHOS X

1. Reduced Extraction Time

The microwave program used in the study is approximately 15 minutes.

The application report describes substantially reduced extraction time compared with the shaker-table approach and reports up to 70% extraction-time reduction.

For high-throughput laboratories, this can substantially change daily workflow.

2. Reduced Manual Handling

Traditional extraction workflows involving repeated transfers require analyst intervention.

Reducing repetitive handling can simplify laboratory operations and potentially reduce opportunities for handling errors.

3. Up to 44 Extraction Positions

The XTR-44 configuration provides a large number of sample positions.

This allows laboratories to process significant sample batches simultaneously.

4. Integrated Stirring

Magnetic stirring supports interaction between the solid matrix and extraction solvent during microwave treatment.

5. More Predictable Turnaround

A controlled microwave program has a clearly defined extraction duration.

That makes scheduling easier than workflows whose extraction stage requires prolonged shaking.

6. Workflow Standardization

Defined temperature, time and microwave conditions can support a more standardized extraction workflow.

7. Reduced Labor Requirement

Reducing extraction duration and manual operations allows analysts to spend more time on other laboratory tasks.

8. Suitable for Different Solid Matrices

The application report specifically discusses soils, sediments and biosolids as important solid matrices for PFAS determination.

This makes microwave-assisted extraction relevant to environmental laboratories receiving varied solid sample types.

PART 3 – EPA 1633 PFAS Sample Preparation and Laboratory Productivity

Environmental laboratories rarely evaluate new sample-preparation equipment based solely on extraction efficiency.

The complete laboratory economics must also be considered.

This includes:

analyst time,

sample throughput,

repeatability,

available bench space,

turnaround time,

training,

consumables,

QC requirements,

and instrument utilization.

PFAS Extraction using Milestone ETHOS X addresses several of these workflow considerations simultaneously.

Higher Throughput for Commercial PFAS Laboratories

Commercial environmental laboratories often receive large batches of samples.

During urgent environmental investigations or remediation projects, sample numbers may increase rapidly.

The ability to process multiple samples in parallel becomes particularly important.

The XTR-44 rotor’s 44 positions make the ETHOS X configuration suitable for laboratories seeking higher PFAS extraction capacity.

Instead of thinking only about extraction time per individual sample, laboratories should consider batch productivity.

A controlled 15-minute microwave extraction program combined with multi-position processing can improve the overall sample-preparation schedule.

Reducing the Sample-Preparation Bottleneck

Modern LC-MS/MS systems can process large analytical sequences.

However, if sample preparation cannot supply extracts efficiently, the analytical instrument may not be utilized optimally.

This creates a bottleneck.

Faster PFAS sample extraction can help laboratories balance sample preparation with instrumental capacity.

Consistency in PFAS Extraction

PFAS analysis requires careful quality control.

A repeatable extraction program provides defined processing conditions across samples.

The ETHOS X system controls important extraction parameters including temperature, microwave power and time.

Integrated magnetic stirring adds another controlled aspect to the extraction environment.

The Milestone report concluded that the evaluated system demonstrated comparability, precision and PT performance for the tested solid matrices.

Microwave Extraction and Modern Environmental Sample Preparation

The second Milestone document provides useful broader context.

The microplastics white paper examines microwave-assisted sample preparation for environmental analysis.

In one application, microwave-assisted solvent extraction was combined with analytical pyrolysis for investigating plasticizers and microplastics in beach sand.

Extraction tests were performed using a microwave ETHOS system.

The researchers evaluated extraction at 60°C and 80°C using 600 W irradiation for 60 minutes, with the best extraction yields reported at 80°C for the evaluated application.

This is not a PFAS extraction method and the operating conditions should not be transferred to EPA 1633 PFAS analysis.

However, it demonstrates an important broader principle:

microwave-assisted solvent extraction can be adapted to challenging environmental matrices through application-specific control of temperature, power and extraction conditions.

The same broader technology platform can therefore support very different analytical workflows when appropriately configured and validated.

Who Can Benefit from Milestone ETHOS X PFAS Extraction?

The technology may be relevant to:

Environmental testing laboratories

Commercial PFAS laboratories

Government environmental laboratories

Research institutions

Soil testing laboratories

Waste and remediation laboratories

Biosolids testing facilities

Environmental monitoring organizations

Contract analytical laboratories

Academic PFAS research groups

Any laboratory considering implementation should assess the technique within its own quality system and applicable regulatory requirements.

PFAS Extraction from Sediment

Sediment can be a challenging environmental matrix because its composition can vary substantially depending on sampling location.

A controlled extraction technique is useful when laboratories routinely encounter different matrices.

The ETHOS X approach provides defined microwave conditions combined with stirring, making it an interesting option for PFAS extraction from sediment.

The Milestone application report identifies robust extraction across varying incoming matrices as one of the benefits of the ETHOS X/XTR-44 workflow.

PFAS Extraction from Biosolids

Biosolids represent another important matrix for PFAS monitoring.

Complex solid composition can make sample preparation particularly important.

Microwave-assisted extraction offers laboratories a controlled approach for processing solid samples before subsequent cleanup and LC-MS/MS analysis.

The Milestone report specifically positions ETHOS X extraction as relevant to PFAS extraction challenges involving soils, sediments and biosolids.

PART 4 – Why Consider Milestone ETHOS X for PFAS Extraction?

The growing analytical focus on PFAS creates pressure on laboratories to increase capacity while maintaining confidence in analytical results.

Simply adding more LC-MS/MS capacity may not solve the problem if sample preparation remains slow.

Improving the extraction stage can therefore be an important component of laboratory optimization.

PFAS Extraction using Milestone ETHOS X combines microwave-assisted extraction, integrated stirring and high-capacity sample processing in a controlled workflow.

ETHOS X with XTR-44

A particularly important component of the PFAS application is the XTR-44 rotor.

The 44-position rotor enables simultaneous processing of multiple extraction tubes.

The evaluated equipment configuration included:

Milestone ETHOS X

XTR-44 rotor

magnetic stirring

50 mL disposable polypropylene vials

centrifugation or SFS-24 filtration

nitrogen evaporation

automated SPE

and LC-MS/MS for final determination.

The ETHOS X therefore forms the extraction stage of a broader analytical workflow rather than replacing subsequent cleanup and instrumental analysis.

Traditional Shaker Extraction vs Microwave PFAS Extraction

Traditional shaker extraction is familiar to many laboratories.

However, the Milestone application identifies several practical issues with the workflow, particularly the time and labor associated with multiple extraction and transfer operations.

Microwave-assisted extraction aims to simplify this stage.

The practical difference can be summarized as:

Shaker Table Extraction

Longer elapsed extraction workflow
More manual handling
Multiple transfer operations
Greater analyst involvement
Lower predictability of sample-preparation scheduling

ETHOS X Microwave Extraction

Controlled microwave program
Approximately 15-minute evaluated extraction program
Parallel processing with XTR-44
Integrated stirring
Reduced repetitive handling
Potentially easier scheduling and throughput management

The best workflow for a particular laboratory should still be determined through its own method verification, validation and quality requirements.

PFAS Analysis by LC-MS/MS After ETHOS X Extraction

It is important to distinguish PFAS extraction from PFAS measurement.

ETHOS X prepares the sample by performing the microwave-assisted extraction.

The extract then proceeds through the required preparation and cleanup procedures before final analysis.

In the Milestone study, extracts were analyzed according to EPA 1633A using an LC system interfaced with a triple-quadrupole mass spectrometer.

Therefore, ETHOS X should be considered part of the PFAS sample preparation workflow, not the final PFAS detector.

This distinction is particularly important when laboratories search for terms such as:

PFAS analyzer,

PFAS testing equipment,

PFAS extraction equipment,

EPA 1633 equipment,

PFAS sample preparation system,

or

PFAS testing by LC-MS/MS.

Frequently Asked Questions About PFAS Extraction Using Milestone ETHOS X

What is PFAS Extraction using Milestone ETHOS X?

It is a microwave-assisted sample-preparation approach in which solid environmental samples are treated with an appropriate extraction solvent under controlled microwave conditions before subsequent cleanup and LC-MS/MS analysis.

Can Milestone ETHOS X be used for EPA Method 1633 PFAS extraction?

Milestone has reported an application evaluating the ETHOS X with XTR-44 for EPA Method 1633A target analytes in solid matrices. Laboratories should follow their applicable regulatory, accreditation, verification and validation requirements when implementing an alternative extraction workflow.

What samples can be processed for PFAS extraction?

The application discusses solid matrices such as soil, sediment and biosolids.

How long does ETHOS X PFAS microwave extraction take?

The evaluated microwave program consisted of a 5-minute step followed by a 10-minute step at 65°C, giving approximately 15 minutes of programmed microwave extraction.

What solvent was used for PFAS extraction?

The reported study used 15 mL of 0.3% ammoniacal methanol for the evaluated samples and QC materials.

What is the XTR-44 rotor?

XTR-44 is the extraction rotor used with ETHOS X in the PFAS application. It provides 44 positions, supporting high-throughput sample processing.

Does ETHOS X replace LC-MS/MS?

No.

ETHOS X performs the microwave-assisted extraction/sample-preparation stage.

Final PFAS determination in the reported EPA 1633A workflow was performed using LC-MS/MS.

Can microwave extraction reduce PFAS extraction time?

According to the Milestone application report, microwave-assisted extraction can provide up to approximately 70% reduction in extraction time compared with the conventional shaker-table approach evaluated.

Why is PFAS sample preparation important?

Accurate instrumental analysis depends on appropriate extraction and preparation of target compounds from the original sample matrix. Sample preparation can also represent a major portion of analyst labor and total laboratory turnaround time.

Is microwave extraction suitable for high-throughput PFAS laboratories?

The XTR-44 configuration offers 44 positions and a short controlled extraction program, making the approach particularly relevant to laboratories seeking increased PFAS sample-preparation capacity.

Improving PFAS Laboratory Efficiency

The economics of PFAS testing involve more than the analytical instrument itself.

Laboratories should consider how much analyst time is required to prepare each batch.

If sample preparation takes several hours and requires repeated analyst intervention, expanding analytical capacity alone may not significantly improve turnaround.

Automating or accelerating extraction can therefore have a larger operational effect than expected.

The Milestone application identifies several potential benefits from the ETHOS X approach:

increased capacity,

ability to accommodate urgent soil samples,

reduced labor,

reduced elapsed extraction time,

better predictability of turnaround,

improved consistency,

robust extraction across different matrices,

and easier workflow implementation for laboratory staff.

These benefits explain why microwave-assisted extraction for PFAS can be important for laboratories experiencing increasing sample volumes.

PFAS Extraction Equipment for Environmental Laboratories

When choosing PFAS extraction equipment, laboratories should evaluate more than just heating performance.

Important factors include:

sample capacity,

vessel material,

contamination control,

temperature control,

stirring,

workflow reproducibility,

cleaning requirements,

extraction time,

operator involvement,

compatibility with downstream SPE,

and compatibility with the laboratory’s validated analytical method.

The Milestone ETHOS X with XTR-44 addresses many of these workflow considerations through microwave-assisted extraction and parallel sample processing.

Conclusion: PFAS Extraction Using Milestone ETHOS X

PFAS analysis is increasingly demanding efficient and reproducible sample-preparation workflows.

For laboratories analyzing PFAS in solid environmental matrices, extraction can become one of the most labor-intensive stages of the complete analytical process.

PFAS Extraction using Milestone ETHOS X provides a microwave-assisted approach designed to simplify this critical stage.

The Milestone PFAS application report demonstrates the use of the ETHOS X with XTR-44 rotor and integrated stirring for extraction of EPA 1633A target analytes from solid matrices.

The evaluated microwave program operates at 65°C with approximately 15 minutes of programmed extraction. The study compared microwave extraction with shaker-table extraction and reported strong comparability across the evaluated samples and successful PT/reference-material performance.

For laboratories, the potential benefits extend beyond extraction speed.

Higher capacity, reduced repetitive handling, more predictable turnaround, controlled extraction conditions and easier workflow implementation can collectively improve laboratory productivity.

The XTR-44 rotor’s 44 positions make the system particularly relevant to high-throughput environmental laboratories processing large batches of PFAS samples.

The application report also demonstrates an important analytical principle: improving sample preparation can improve the efficiency of the entire PFAS testing workflow.

For laboratories searching for PFAS extraction equipment, PFAS Extraction using Milestone ETHOS X, EPA 1633 PFAS extraction, EPA 1633A sample preparation, PFAS extraction from soil, PFAS extraction from sediment, PFAS extraction from biosolids, microwave-assisted PFAS extraction, PFAS sample preparation equipment, or high-throughput PFAS extraction, the Milestone ETHOS X represents a technically documented microwave-assisted extraction approach worth evaluating within the laboratory’s own validated quality framework.

As PFAS testing volumes continue to place demands on environmental laboratories, faster and more controlled sample preparation can play an increasingly important role in improving analytical throughput.

Milestone ETHOS X with XTR-44 brings microwave-assisted extraction, integrated stirring and high sample capacity together to provide an efficient approach to PFAS extraction from solid environmental matrices before LC-MS/MS determination.