The PFAS test trusted by firefighters and first responders, now available for everyone!
August 15, 2024

The Technologies Behind Relentless Health's PFAS Test 

Richard Kho, PhD
The Technologies Behind Relentless Health's PFAS Test 

Relentless Health delivers reliable and affordable PFAS testing using the latest at-home blood sample collection techniques. This is backed up by state-of-the-art laboratory technology which allows us to provide accurate test results in days. Learn more about our testing technology and how you can use this to monitor and reduce your risk of PFAS exposure.

Environmental PFAS testing vs. human PFAS testing

PFAS chemicals have been around for many decades and are widely found in the environment. So, testing for PFAS is very routine in municipal drinking water, wastewater, surface water, groundwater, soil, landfills, and air emissions. The US Environmental Protection Agency (EPA) has developed various standards for PFAS testing in these environments, including sampling methods and analytical procedures.

However, when it comes to human PFAS testing, development has been slower. Until recently the most common approach was to test for PFAS in the blood serum. Think of the typical blood draw by a phlebotomist, a nurse, or a physician when you get your blood-work done during an annual physical. A typical PFAS test uses this same method, called “venous blood draw.” The National Health and Nutrition Examination Survey (NHANES) began measuring PFAS levels in blood using this venous blood draw method in 1999. But regular monitoring of human PFAS levels using venous blood draw is expensive, time consuming, and inconvenient, so newer methods were needed. 

Blood microsampling for human PFAS testing

Recent advances in remote blood sampling has enabled Relentless Health to develop its PFAS test as an at-home test. Known technically as “Volumetrically Accurate Microsampling Collection Devices,” these FDA-cleared blood sampling devices can be used to collect just a few drops of blood while still allowing for accurate testing. In our PFAST-24 test, individuals use the supplied at-home collection kit to take a blood sample in minutes. Sample collection starts with thorough hand washing, followed by cleaning the finger tip with an alcohol wipe. Then, the supplied lancet is used to prick the finger tip with minimal discomfort. Two to three drops of blood are applied to the microsampling collection device tip, which collects and stores the blood. Finally, the collection device containing the blood drop sample is shipped in a prepaid envelope to Relentless Health’s central lab for processing and analysis.

State-of-the-Art Scientific instruments and methods

The Relentless Health PFAS test Uses State-of-the-Art scientific instruments and methods. These have been proven to deliver accurate and reliable results.

Liquid chromatography and mass spectrometry

The laboratory technique used to detect PFAS in blood is called liquid chromatography-mass spectrometry (LC-MS). LC-MS allows scientists to identify and quantify chemical compounds of interest, and is widely used in a range of analytical methods.

Preparing the sample

At Relentless Health, our PFAS testing uses strict, quality-controlled processes for sample preparation and analysis. The main purpose of sample preparation is to dissolve the dried blood sample so we can analyze it for PFAS. We do this by using laboratory-grade solvents and materials to return the dried blood (and its contents) into a liquid that can then be injected into the LC-MS instrument for analysis. This requires multiple steps of preparation that are carried out by one of our qualified laboratory technicians. All our sample preparation methods are validated and have been verified in multiple laboratories.

Injecting and splitting the sample

Once the sample is prepared, it is injected into the LC-MS instrument. The solution flows through the instrument and enters a liquid chromatography analytical column–a part of the instrument that helps to separate the 24 PFAS compounds. Each PFAS compound interacts with the inside of the LC column differently, and exits the column at a different time as the solution continues to flow through the system. For example, a compound that interacts weakly with the analytical column will exit the column earlier than one that interacts strongly. 

The role of the mass spectrometer

Once the 24 PFAS compounds are separated by the LC column, they enter the mass spectrometer part of the instrument. In the mass spectrometer, the compounds are first converted from neutral molecules to ions (charged particles), and the ions then enter the detector within the MS instrument. The detector is engineered in a way that allows us to very accurately measure the mass of each ionized chemical that enters it. Therefore, in our test each compound is characterized by 1) the specific time it exits the analytical LC column, and 2) the mass of the compound as determined by the MS. As the mass of the PFAS compounds is known from their chemical structures, the detected mass in the LC-MS system can be matched with the PFAS compounds of interest.

Quantifying the PFAS compounds

The LC-MS signal recorded for each PFAS compound is also used to quantify the amount of that PFAS. This allows us to calculate the concentration of PFAS in the analyzed sample (typically in “ng/mL” or nanograms per milliliter), from which we can work out the PFAS concentration in the blood. This is the value that is recorded in the PFAS report. 

Delivering quality, test after test

Relentless Health performs ongoing quality control of all its systems and labs. We have an extensive quality control system with detailed documentation and protocols for every eventuality. The LC-MS instrument is calibrated and tested daily. We also have a schedule of routine maintenance and quality testing, validation, and verification to ensure ongoing optimal performance and accuracy. 

To learn more about the Relentless Health PFAS test, head over to the PFAST-24 page.