Environmental Laboratory - Focus on PFAS Analysis PFAS HPLC columns provide fast and high-resolution LC-MS separation


technology and a particle size of 2.7 µm, delivers fast and high-resolution separations with excellent selectivity and lower column back pressure compared to sub-2 µm particles, peak shape, and necessary retention to perform in EPA methods 537.1, 533 and 8327.


Ascentis® Express PFAS columns offer excellent suitability for MS detection, application-related lot analysis and single column performance testing. Ascentis® Express PFAS


HPLC columns enable precise MS results; it is designed for the separation of novel and legacy short chain and long chain PFAS compounds containing branched and linear isomers, whilst adhering to EPA methodology requirements. Furthermore, a specifi c PFAS delay column prevents background PFAS contamination from interfering with the sample results in quantitative LC-MS methods.


What are PFAS chemicals? Sources, analysis, health effects and removal


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Indeed, the carbon-fl uorine bond which joins PFAS chemicals together is one of the strongest known to science. For this reason, it may take a thousand years or more for PFAS to decompose in the environment, meaning they will undoubtedly outlive the products which contained them and the people who used. For some PFAS, scientists are not even able to estimate their half-life (the amount of time which elapses before 50% of a chemical decomposes fully), indicating their persistence and explaining their nickname of “forever chemicals”.


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The fi rst PFAs were developed in the 1940s and used widely in the United States and beyond. As our understanding of how they endure in the atmosphere and how they affect plant and animal life on the planet has advanced, PFAS have come to be regarded as potentially dangerous, with several of them now completely outlawed in America, Europe and many other parts of the world. However, they continue to infi ltrate water, soil, air, biological matter, animals and even the human body, causing potentially damaging repercussions for human health.


What are the different types of PFAS?


Given that there are over 4,700 known PFAS (and more are being developed by industry all the time), it would be impossible to give even a cursory list of known types of PFAS here. However, it is possible to explain the basic characteristics which they all share. Specifi cally, all PFAS carry a similar molecular structure, consisting of a chain of carbon atoms and a fl uorine element.


They can be further divided into polymer and non-polymer PFAS, which simply relates to the length of the carbon chain inherent in their makeup. Since “poly” means “many” and “mer” means “segment”, polymer PFAS are those which are made up of long chains of segments, while non- polymer PFAS refer to all others. Non-polymer PFAS are also made up of carbon chains, though these are usually only between three and 12 segments in length. Generally speaking, the shorter the chain, the more mobile and easily transferrable the PFAS is to the natural environment.


Two of the most notorious non-polymers are perfl uorocarboxylic acids (PFOA) and perfl uorosulfonates (PFOS), about which the majority of research into PFAS has been conducted and from which most of our understanding of these chemicals stems. They have both since been phased out by governments in the UK, the USA and the EU – but are still widespread in many industrial processes in other parts of the world and as such, can easily be imported into the countries where they are prohibited and contaminate the environment.


What are PFAS chemicals used for?


There are a wide variety of different applications for PFAS chemicals, including (but not limited to) the following: - To apply a non-stick coating to pots, pans and other household cookware - To create a stain-repellent effect on carpets, fabrics, clothes and other textiles - To enhance the effectiveness of cleaning products, paints and waxes - To make the foam used by fi refi ghters - To lubricate machine mechanisms, for example in bike oil - To give waterproof clothing its rain-resistant properties - To package foodstuffs


This is by no means an exhaustive list of the uses to which PFAS chemicals are put. In fact, more chemicals are being invented all the time to satisfy new and innovative applications, making it increasingly diffi cult to categorically itemise the uses of PFAS chemicals.


Which items contain PFAS?


As mentioned above, PFAS are most commonly found in everyday products that may be bought and consumed by normal citizens such as non-stick pans, paints, waxes, oils, stain-repellents, waterproof clothing, food packaging and many more. However, the industrial uses of PFAS are just as numerous, meaning that PFAS chemicals can also be found in electronics manufacturing materials, chrome plating equipment, processing machinery and fi refi ghter foam, among many, many other items.


How can PFAS infi ltrate water supplies?


There are a number of ways in which PFAS can enter our water supplies. They can leach off the products in which they are contained both during and after use. Oil can be washed off bike chains by the rain, clothes can lose their stain-repellent or waterproof properties when washed at extreme


Perfl uoroalkyl and polyfl uoroalkyl substances – more commonly known as PFAS – are a group of more than 4,700 manmade chemicals that are used for a wide variety of different purposes in a range of industries. Sometimes known as “forever chemicals”, PFAS are notable for the length of time which they are able to persist in the natural environment.


temperatures, and pans can shed their non-stick coating if used on an intense fl ame. Of course, the persistence of PFAS means they can also simply infi ltrate the atmosphere once they have been disposed of.


From here, they can be channelled through sewerage systems to wastewater treatment plants, where the techniques in place are not capable of removing them from the effl uent entirely. Once they have passed through such sites, they can fi nd their way into rivers, streams and reservoirs, thus potentially affecting the water supply.


How can you test water supplies for PFAS?


In order to test water supplies for the presence of PFAS chemicals, it’s important to use a certifi ed laboratory staffed by experienced professionals to ensure reliable results. Traditionally, PFAS analytical methods have relied upon the separation and identifi cation of each individual component of a sample to ascertain whether any PFAS components are present. Given that there are literally thousands of PFAS components which have been produced and are now in widespread circulation, such a task is understandably an onerous one.


For that reason, the scientifi c community has been searching for more advanced ways to simplify the process through a fast, effi cient and dependable screening method. For those interested in learning more about the latest developments in this area, the article Screening technique for Adsorbable Organic Fluoride (AOF) concentrations with the Xprep C-IC holds much useful information.


How else are people exposed to PFAS chemicals?


As well as drinking PFAS through water supplies, there are a wide array of other ways in which humans can become exposed to the chemicals. That’s due to the fact that PFAS are both highly mobile and incredibly persistent, meaning they can permeate all kinds of environments and substances.


For example, you might breathe in PFAS that are present in the ambient air – even if you do not live in the vicinity of a factory or facility which uses PFAS in its daily operations. It’s also common to ingest PFAS through the food we eat, which can occur in a number of ways. Firstly, if you are eating meat or fi sh, it’s possible that the animal itself has consumed PFAS from its prey. The persistence of the chemicals mean that they accumulate in the bodies of the smallest organisms to begin with, which are then consumed by larger and larger members of the food chain. Although they are present in tiny concentrations at the outset, they can build up to alarming accumulations over time.


Meanwhile, PFAS can also be present in vegetarian and vegan food, either through being grown in contaminated soils, being irrigated with contaminated water, being processed in a factory in which PFAS are present or being stored in packaging made up of PFAS elements. Virtually ubiquitous, PFAS have been found to be present in the bloodstreams of over 99% of the American populace – and it’s believed that similar trends are to be observed in the citizens of countries all around the world.


What are the effects of PFAS on the human body?


Here comes the concerning part – PFAS can have a hugely detrimental impact on human health after prolonged exposure. Several studies of laboratory animals have found that high levels of PFAS in the bloodstream can cause a number of serious health complications, including high cholesterol, kidney cancer, pregnancy-induced hypertension, thyroid disease, testicular cancer and ulcerative colitis.


While more study is required to fully understand the impacts of PFAS on the human body, many of the chemicals are suspected of being carcinogenic, toxic to certain bodily organs, damaging to babies being breastfed PFAS-rich milk and detrimental to reproductive capabilities. Documented effects of PFAS exposure include low infant birth weights, disruption to the thyroid hormones, negative impacts on the immune system and the contraction of cancer.


What does the law say on PFAS?


While the two aforementioned notorious PFAS (PFOA and PFOS) have been banned in much of the western world, they are still unfortunately widely used in parts of the globe where regulations are laxer. The fact that they can then be imported into any country or simply infi ltrate the atmosphere of any location on the planet means that they continue to pollute our environment, while their persistence means that they are unlikely to be eradicated any time soon.


At the same time, many industrial manufacturers have moved away from those PFAS in favour of other chemicals belonging to the same group, but with shorter carbon chains. While these chemicals have not been conclusively proven to be dangerous, neither are they defi nitively safe. In fact, recent research suggests that they may be just as damaging as PFOA and PFOS chemicals, meaning that industry has simply replaced one contaminant with another.


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PFAS (Per- and poly-fl uoroalkyl substances) are persistent, man-made organic compounds, widely found in the environment. Recent awareness has brought attention to the toxicity of these substances. The U.S. Food and Drug Administration (FDA) and the U.S. Environmental Protection Agency (EPA) have initiated actions against PFAS. For determination of PFAS, liquid chromatography–mass spectrometry (LC-MS) is a commonly used technique. Merck’s new Ascentis® Fused-Core®


Express PFAS HPLC column, with its


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