We offer PFAS analysis of soil and biosolids (dried sludge from wastewater treatment plants, often applied as fertilizer to farms) samples using draft EPA method 1633. This method includes the analysis of 40 different PFAS compounds. First, the PFAS compounds are extracted from the solids. The extract is then treated with various sorbents to remove interfering compounds, and then subjected to Liquid Chromatography/Tandem Mass Spectrometry for analysis.Get Started
Soil samples are prepared by an in-house method we developed and reported in 2005, which has become the basis for many environmental analytical PFAS methods. The method utilizes a rapid sample purification procedure to remove matrix components sufficiently so that errors due to coeluting matrix peaks are negligible and recoveries of PFAS are consistently and reproducibly quantitative. Extracts from solid samples (soil and sediment) and liquid bacterial sludge are purified using dispersive solid-phase extraction. Recovery values generally are in the 70-120% range. The method utilizes an extraction solvent previously shown to release and recover aged residues of PFAS. This essentially means we remove junk from the samples that would normally interfere with PFAS analysis.
The table below is our biosolid data from two different wastewater treatment plant sites that were tested by using the draft EPA method 1633. The numbers shown are the concentrations of the PFAS detected using this method. Note that some of the long chain PFAS compounds (10 or more carbon units) are readily detected, even though they are rarely detected in water. The reason for this is because typically, partitioning of PFAS into organic matter increases with chain length.
The graph below is our biosolid and soil data from a farm plot treated with biosolids. We tested soils at two different depths and the biosolids that were applied to the soils for PFAS using draft EPA method 1633. See an example of what we found below.