Per- and polyfluoroalkyl substances (PFAS) — including well-known compounds like PFOA (perfluorooctanoic acid) — are a class of synthetic chemicals derived from fluorinated hydrocarbons. Because the carbon-fluorine bond is one of the strongest in organic chemistry, PFAS persist indefinitely in the environment, earning them the name “forever chemicals.”
Historically incorporated into non-stick coatings, fire-resistant materials, water-repellent packaging, and pesticides, PFAS are now detectable in drinking water, soil, and biological tissue worldwide. Due to their persistence and well-documented adverse effects on human health and the environment, the U.S. Environmental Protection Agency (EPA) has established rigorous testing guidelines for PFAS across multiple sample matrices.
EPA Methods for PFAS Testing
| EPA Method | Sample Matrix | Minimum Detection Limit (MDL / Reporting Level) | Description |
| EPA 537.1 (v2.0) | Drinking water | ~2 ng/L or lower | Improved version of 537 with 18 PFAS, better QA/QC and faster workflow; widely used for regulatory compliance |
| EPA 533 (2019) | Drinking water | ~1–5 ng/L | Uses isotope dilution + anion exchange SPE; optimized for short-chain PFAS not well captured in 537.1 |
| EPA 8327 | Non-potable water (groundwater, wastewater, etc.) | ~10–100 ng/L (method dependent) | “Dilute-and-shoot” LC-MS/MS method; faster but less sensitive than drinking water methods; external calibration |
| EPA 1633 | Multi-matrix (water, soil, sediment, biosolids, tissue) | ~1–10 ng/L (matrix dependent) |
Most comprehensive method (~40 PFAS); designed for CERCLA / environmental investigations; multi-matrix capability |
As analytical methods become more sensitive — routinely reaching detection limits in the parts-per-trillion (ppt) range — the risk of contamination from laboratory consumables becomes a critical concern. Even trace levels of PFAS introduced by sample preparation materials can compromise results at these concentrations.
PFAS are commonly present in:
- Tubing and seals (e.g., PTFE)
- Filters and Membranes
- Sample containers and caps
- Laboratory environments
Even trace contamination can lead to:
- False positives
- Failed QA/QC criteria
- Compromised regulatory compliance
Sterlitech PFAS-Free Sample Preparation Products
Sterlitech provides sample preparation products that support contamination free workflow. Our PFAS-Free Syringe Filters, PFAS-Free Membrane Filters, and PFAS-Free Syringeless Vials are made from raw materials manufactured free of PFAS Contamination.
| Syringe Filters | ||
| Membrane Material | Pore Size (um) | Diameter (mm) |
| PES | 0.22, 0.45 | 13, 25, 33 |
| Nylon | 0.22, 0.45 | 13, 25, 33 |
| Regenerated Cellulose | 0.22, 0.45 | 13, 25 |
| Cellulose Acetate | 0.2, 0.45, 0.8, 1.2, 5.0 | 13, 25 |
| Glass Fiber | 0.45, 0.7, 1.0, 1.2, 3.1 | 25 |
| Membrane Filters | ||
| Material | Pore Size (um) | Diameter (mm) |
| PES | 0.2, 0.45 | 47 |
| Nylon | 0.2, 0.45 | 47 |
Control Contamination by Reducing Steps in Your Sample Preparation Workflow
Separa® filter vials combine the function of a syringe filter and an autosampler vial in one by integrating a membrane in the cap, removing the use of syringes in syringe filtration. Its compact design and compatibility with UHPLC and HPLC Autosamplers reduce contamination from subsequent transfer of the sample container to a syringe, through a syringe filter to be dispensed in an autosampler vial.
Traditional Filtration using a Syringe Filter
- Fill the syringe with the sample
- Attach the syringe filter (luer lock connection)
- Push the plunger to filter into an autosampler vial
- Cap the vial for HPLC analysis
Each transfer step introduces potential contamination.
Syringeless Filtration using Separa®
Sterlitech PFAS-Free products are designed to help laboratories maintain compliance with stringent EPA regulatory standards, by reducing false positives, and improving analytical confidence.
As PFAS testing regulations continue to evolve, choosing the right products is becoming an analytical necessity. Request a quote today for Sterlitech PFAS-Free products.
Global plastic production now exceeds 460 million tons per year, and microplastics are now being detected everywhere from oceans to human tissue. In filtration and membrane science, this is not an abstract issue. It is something that is measured, tracked, and increasingly studied. As the research continues to develop tools to assess the impact on human health and the environment, it is reasonable to also examine what is happening on the materials side.
Shellworks, a London-based biomaterials company, recently closed a $15 million Series A to scale a plastic alternative called Vivomer. This technology is worth understanding, particularly for researchers and engineers working in environmental monitoring and microplastics analysis, where shifts in material science directly influence what enters the filtration and analytical workflows used to study microplastics.
Material Science
Vivomer is a polyhydroxyalkanoate, or PHA, a class of biopolyesters synthesized intracellularly by certain microorganisms as a form of carbon and energy storage. Shellworks produces through microbial fermentation using second-generation feedstocks, specifically waste streams like used cooking oil, rather than food-competing crops. The microbes accumulate PHA granules, which are then extracted and processed into a thermoplastic resin that can be formed using conventional techniques including blow molding.
PHAs have been studied since the 1920s and attracted serious commercial interest since the 1980s. What has historically held them back is production cost and the difficulty of achieving consistent mechanical properties at scale. Shellworks' claim is that six years of process development has moved Vivomer past both of those hurdles, at least relative to comparable rigid packaging materials.
The biodegradation profile is also worth noting. Unlike PLA (polylactic acid), which requires industrial composting conditions to break down, PHAs can biodegrade in soil and marine environments through enzymatic hydrolysis, This distinction that matters significantly from a lifecycle and environmental fate perspective, and one that has direct relevance to anyone working in environmental monitoring or microplastics research.
Where Things Stand Commercially
Shellworks says Vivomer has reached cost parity with glass and aluminum at approximately 5 million units of production. That's a meaningful benchmark, because glass and aluminum are the materials brands typically reach for when they want to move away from plastic, not because they are cheap, but because they are recyclable and consumer-facing. Competing on cost at that volume, before the economics of scale have fully kicked in, is a stronger position than most PHA producers have managed.
The material is already commercially used. Brands including Wild (Unilever) and Sonsie Skin have launched products in Vivomer packaging, available through Tesco in the UK and Whole Foods in the US. These are real supply chains with real quality requirements, which is a different kind of validation than a lab-scale demonstration.
The 15-million-dollar Series A, led by Alter Equity, with participation from Nat Friedman of NFDG, JamJar Investments, Founder Collective, and LocalGlobe, will go toward expanding manufacturing capacity in the US and Europe and further developing processing capabilities around blow molding for large format packaging.
Reference
Vignesh R. "Plastic without plastic: Shellworks' $15M bet on microbe-made packaging." Tech Funding News, 4 March 2026. https://techfundingnews.com/shellworks-15m-series-a-vivomer-plastic-alternative/
Desalination removes salt and other minerals from water, producing two primary streams: freshwater and brine. As desalination capacity grows, effective brine management is becoming essential to reduce environmental impact and improve overall water recovery.
Effective treatment of brine can result in higher water recovery and utilization of salts as a resource. Several membrane processes can be used for brine treatment and management; this includes Reverse Osmosis (RO), Osmosis Assisted Reverse Osmosis (OARO), Forward Osmosis (FO), and Membrane Distillation (MD).
Reverse Osmosis (RO)
Reverse osmosis is the most mature and widely used membrane process for desalination applications. As osmotic pressure increases, conventional seawater RO (operating under 80 bar) cannot concentrate saline water with TDS higher than ~45 g/l [1]. The introduction of High-Pressure Reverse Osmosis membranes extend this capability, designed to withstand pressures up to 120 bar, which can concentrate brines up to a maximum of 135 g/l TDS [2].
An advantage is high water recovery at relatively low specific energy compared with thermal evaporation, especially when salinity is moderate. However, as brine salinity rises, osmotic pressure and required operating pressure climb sharply, which sets practical limits on achievable concentration and recovery.
Evaluating the pressure efficiency and tendency to fouling can be done using Sterlitech’s high pressure testing cells HP4750X, and Sepa CFX. These cells are designed to resist high pressure up to 2500 psi and are available in 316L, Dursan coated 316L and C276 options. High pressure fully assembled skid systems are available with similar pressure values and material.
Osmosis Assisted Reverse Osmosis (OARO)
OARO uses a high salinity feed and a lower salinity draw solution on the permeate side to reduce the osmotic pressure drop across the RO membrane. This sustains flux at lower applied pressure than pushing against full brine osmotic pressure in conventional RO.
OARO advantages include higher attainable recovery and reduced mechanical stress on membranes. However, the need to continuously regenerate the draw, added process complexity, and sensitivity to internal/external concentration polarization that reduces effective driving force.
Sterlitech’s four port (Forward Osmosis) cell can be utilized for OARO testing, including CF016, CF042, and SEPA cells. These cells must be used with a set of shims and spacer on the draw side to provide support for the membrane against the high pressure applied from the feed side.
Membrane Distillation (MD)
MD is suited for brine treatment, especially for RO concentrate and high‑TDS industrial brines, because it can recover water even when salinity exceeds the pressure limits of RO. In brine treatment, MD is typically applied as a post‑RO or near zero liquid discharge step to further concentrate the brine while producing high‑quality distillate, helping reduce liquid discharge volumes.
Key advantages are tolerance to extremely high salinity, near‑complete salt rejection, and operation at low hydraulic pressure, often using waste or low‑grade heat available in industrial plants. However, challenges in brine applications include severe scaling due to salt supersaturation, membrane wetting, declining flux at high concentrations, and thermal efficiency losses, all of which require careful pretreatment, temperature control, and membrane selection.
Sterlitech offers a wide variety of systems and cells suitable for MD testing applications.
Forward Osmosis (FO)
FO uses a highly concentrated draw solution to osmotically extract water from RO concentrate or high‑salinity brines, thereby reducing brine volume and increasing overall water recovery. In brine management applications, FO is often used as a pre‑concentration or hybrid step before thermal processes or crystallization, helping move systems toward low‑liquid‑discharge or zero liquid discharge.
The main advantages of FO for brine treatment are its ability to operate at low hydraulic pressure, lower fouling propensity compared to RO, and its effectiveness with high‑salinity streams that are difficult to treat by pressure‑driven membranes. However, key challenges include draw solution regeneration energy demand, internal concentration polarization limiting flux, reverse salt flux increasing brine salinity, and the need for process integration to make FO economically viable at high brine concentrations.
Sterlitech offers a wide variety of systems and cells suitable for FO testing applications.
Conclusion
Effective brine management requires a combination of membrane technologies to balance recovery, energy use, and operational limits. Conventional and high‑pressure RO are effective at moderate salinities, while OARO extends concentration capability by reducing the effective osmotic pressure and mechanical stress. FO and MD complement RO‑based systems by enabling further water recovery from high‑salinity brines, supporting zero liquid discharge. Each process has inherent trade‑offs related to energy demand, fouling, scaling, and system complexity, making pilot testing and careful process integration essential for developing efficient and sustainable brine treatment solutions
Selecting the right membrane configuration for your specific membrane stream is critical to maximizing recovery while managing cost and complexity. Ask an Expert to learn more about our membrane testing options for Brine treatment and management using membrane processes.
References
[1] Z. Zhang, A. A. Atia, J. A. Andrés-Mañas, G. Zaragoza, and V. Fthenakis, “Comparative techno-economic assessment of osmotically-assisted reverse osmosis and batch-operated vacuum-air-gap membrane distillation for high-salinity water desalination,” Desalination, vol. 532, p. 115737, Mar. 2022, doi: 10.1016/j.desal.2022.115737.
[2] J. Zoshi, “Applying Ultra-High Pressure reverse osmosis in brine management,” Saltworks Technologies, Jan. 20, 2026. https://www.saltworkstech.com/articles/applying-ultra-high-pressure-reverse-osmosis-in-brine-management/
