Drinking Water Testing
The Forever Chemicals
PFAS are manufactured chemicals that are ingredients in various everyday products. These chemicals keep food from sticking to packaging or cookware, make clothes and carpets resistant to stains, and create more effective firefighting foam.
PFAS substances have been used globally for decades and do not break down easily or quickly. PFAS are widespread around the world, even found in remote environments such as the Arctic. There are thousands of PFAS compounds. Initial research suggests some types of PFAS may be linked to health problems.
Perfluorooctanesulfonic acid & Perfluorooctanoic acid
PFAS are analyzed using either the EPA test procedure methods 537 or 537.1.
Method 537 was published by EPA in 2009 and is approved for reporting 14 analytes. This test covers the EPA 2016 Health Advisory, which included perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). Accepted by MADEP Drinking Water Program for Water Quality Sampling Schedule required testing for PFAS6.
Method 537.1 was published by EPA in 2018 and is approved for reporting 18 analytes. This test covers the EPA 2022 Health Advisory, consisting of PFOS and PFOA, plus perfluorobutane sulfonic acid and its potassium salt (PFBS) and for hexafluoropropylene oxide (HFPO) dimer acid and its ammonium salt (“GenX chemicals"). In chemical and product manufacturing, GenX chemicals are considered a replacement for PFOA, and PFBS is considered a replacement for PFOS. Also accepted by MassDEP for the drinking water standard monitoring.
Drinking water health advisories provide information on contaminants that can cause human health effects and are known or anticipated to occur in drinking water. EPA's health advisories are non-enforceable and non-regulatory and provide technical information to agencies and other public health officials on health effects, analytical methods, and treatment technologies associated with drinking water contamination.
Our Process
The first step in the process is to fortify the sample with surrogates and pass it through a solid phase extraction (SPE) cartridge containing polystyrene divinylbenzene (SDVB). This allows for the extraction of the method analytes and the surrogates. Next, the compounds are eluted from the solid phase with a small amount of methanol. After this, the sample is then concentrated to dryness with nitrogen in a heated water bath. They are then adjusted to a 1-mL volume with 96:4% (vol/vol) methanol: water after adding the internal standards.
The extracts are then injected into a liquid chromatograph, where the analytes are separated based on polarity. After this, they are passed into two mass spectrometers in tandem for identification based on the molecular masses of the fragmented compounds. This analysis provides highly precise quantitation of these compounds.
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