Gaseous Standard for PFAS Analysis

Per‑ and polyfluoroalkyl substances (PFAS) are synthetic compounds composed of an alkyl chain whose hydrogen atoms are partly or completely replaced by fluorine atoms. PFAS are very resistant pollutants due to the strength of the carbon–fluorine bond. 

To date, monitoring of these pollutants is mainly carried out in water. 

However, several industrial activities, such as landfills and incinerators, are sources of volatile PFAS. Therefore, monitoring of these substances must also be extended to gaseous matrices. 

There is currently no reference legislation setting limits to concentrations of PFAS in the air. 

In the United States, the Environmental Protection Agency (EPA) has released a standardized method called Other Test Method 50 (OTM‑50). This method introduces a procedure for sampling and analyzing volatile fluorinated compounds (VFCs) in air emissions from stationary sources. 

The aim of this work is the production of a gaseous standard which contains all the PFAS reported in the OTM‑50. 

 
Explore OTM-50 → your PFAS analytical standard 

OTM‑50 

OTM‑50 introduces a procedure for sampling and analyzing volatile fluorinated compounds (VFCs) in air emissions from stationary sources. 

VFCs are short chain PFAS with a maximum of eight carbon atoms. 

In OTM‑50 there is a list of about 30 volatile fluorinated compounds selected as indicators of partial thermal decomposition of longer chain PFAS. 

The method also suggests the composition of the gaseous standard used for the calibration of analytical instruments. 

Production of the Mixture 

The mixtures were produced using a gravimetric method based on ISO 6141. 

More than 15 different mixtures were prepared during the experimental activity. Each mixture contained between 2 and 5 compounds. 

Producing simpler mixtures than the final one allowed the identification of analytical issues and raw material purity problems before preparing the final mixture. 

Analysis of the Mixture 

During the study, different operational and analytical configurations were tested with the aim of verifying the production of stable and reliable gaseous mixtures for environmental monitoring applications. 

The activities carried out made it possible to collect useful data to optimize the production process and validate the technical approach adopted by the laboratory. 

This work confirmed the capability to develop gaseous standards suitable for the needs of laboratories and operators involved in PFAS emission analysis. 

Availability of OTM-50 Gaseous Standards 

Perfecta is now able to produce OTM-50 gaseous standards dedicated to the analysis of volatile fluorinated compounds. 

This achievement represents a further expansion of expertise in the field of highly specialized metrological mixtures. 

The availability of standards developed according to the application requirements of OTM-50 makes it possible to support laboratories, regulatory bodies, and industrial companies involved in emission monitoring and in the development of analytical methodologies dedicated to PFAS. 

The introduction of these standards is part of the continuous innovation path pursued by Perfecta and the SIAD Group in the field of specialty gases and applied metrology. 

Conclusions 

The study carried out made it possible to consolidate the expertise required for the production of gaseous standards dedicated to PFAS covered by OTM-50. 

Today, Perfecta is able to provide the market with solutions developed to support the analysis and monitoring activities of volatile fluorinated compounds. 

This milestone confirms SIAD’s commitment to the development of advanced metrological mixtures and strengthens Perfecta’s role as a technical partner for highly specialized applications in the environmental and analytical sectors. 

Learn how OTM-50 delivers precision PFAS analysis 
 

Research Author:  

Ing. Francesco Pigazzini 
Production Manager for Special and Accredited Gas Mixtures at SIAD S.p.A.