EOF – Extractable organically bound fluorine
The analysis of the sum parameter EOF plays an essential role in obtaining a comprehensive picture of the contamination of a sample with organically bound fluorine. This parameter is of importance in particular for the analysis of environmental samples such as soil, sludge and sediment for fluorine contamination.
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EOF analytics
EOF analyses permit the identification of both known and potentially unknown fluorinated compounds in soil, compost and sewage sludge, a task that is crucial for understanding and tackling environmental pollution caused by these persistent substances. This parameter is often used to assess the effectiveness of environmental protection measures, monitor levels and evaluate health risks that could result from long-term exposure to these chemicals.
What is EOF?
The compounds acquired by EOF, defined by their solubility in the extraction agents, include fluorohydrocarbons, PFASs (per- and polyfluoroalkyl substances) and fluorinated pesticides. These substances are primarily of anthropogenic origin and cause significant risks for the environment and health due to their chemical stability and bioaccumulation.
The sum parameter EOF
EOF (extractable organic fluorine) permits the acquisition of the portion of organically bound fluorine that can be extracted from solid samples using solvents. This sum parameter supplements TOF (total organic fluorine) and AOF (adsorbable organic fluorine) and facilitates the specific identification and quantification of extractable organic fluorine compounds. With sum parameters such as EOF, it is possible to measure quickly and cost-efficiently the total concentration of certain substance classes and in this way acquire the overall levels of fluorinated compounds in a sample.
The characteristics of extractable organic fluorine compounds
Extractable organic fluorine compounds are characterised by their high chemical and thermal stability, which is primarily due to the strong bond between carbon and fluorine. These bonds are among the strongest organic bonds and give EOF extraordinary resistance to biological breakdown and environmental effects. Due to these characteristics, the compounds are extremely persistent in the environment and can accumulate over long periods.
Bioaccumulative and water-soluble
Also, many of these compounds are soluble in water and lipids, a characteristic that increases their ability to bioaccumulate and travel large distances. These physical-chemical characteristics make the monitoring and regulation of EOF particularly important, because the compounds can have potentially toxic effects on human health. Their presence in many environmental media therefore represents a serious problem that requires specialised analytical methods and comprehensive environmental management strategies.
The analysis of the sum parameter EOF
at Quality Analysis
As an essential screening parameter, EOF permits the efficient preliminary estimation of the fluorine contamination including PFASs (per- and polyfluoroalkyl substances) as well as other organic compounds containing fluorine. Our expertise permits the effective identification and quantification of extractable organic fluorine compounds in solid matrices such as soil and sediment.
- Quick, reliable screening of EOF in various sample matrices to obtain a complete picture of the fluorine contamination in your sample
- Highly precise analytics by means of the use of combustion ion chromatography (CIC)
- Our analysis meets the applicable standards such as ASTM D7359-08
- Screening of low concentrations in environmental samples down to the determination limit of 50 µg/kg
How is the sum parameter EOF analysed?
EOF analysis is an important method in the non-specific screening of per- and polyfluoroalkyl substances (PFASs). The use of combustion ion chromatography (CIC) provides precise, sensitive results, because it permits a quick, efficient estimation of potential contamination with PFASs and other organic fluorine compounds.
Sample preparation for EOF analytics
For the determination of EOF, initially extraction using organic solvents, for instance methanol or acetonitrile, is necessary. The extraction step is used to isolate the extractable organically bound fluorine from the sample matrix and to prepare it for the subsequent analysis. By means of extraction using a specific solvent, the fluoroorganic compounds are transferred to the solvent, while non-fluorinated compounds remain in the sample.
Combustion of the sample extracted
Extraction is followed by the actual determination of EOF using combustion ion chromatography (CIC). During this process, the sample extracted is combusted and converted from organically bound fluorine into fluoride ions. These fluoride ions are then released into a flow of oxygen and transported to the ion chromatography.
Highly sensitive, precise analytical method
CIC permits the exact, differentiated analysis of the fluoride ions, as a consequence precise results are obtained in relation to the presence and the concentration of extractable fluorine compounds in the sample.
The result of the EOF analysis
The result of the EOF analysis provides essential insights into the extent of fluorine contamination. An elevated EOF figure is indicative of a significant concentration of extractable PFASs, which reflects not only environmental pollution, but also the potential risk for biological systems and human health. These data are crucial for understanding the extent and effects of PFASs in the environment and developing effective countermeasures.
EOF analytics and PFASs
EOF (extractable organically bound fluorine) provides important insights into the contamination of the environment by PFASs (per- and polyfluoroalkyl substances), which represent a large number of chemical compounds known for their chemical stability and persistence. Due to their water, grease and dirt repelling characteristics, PFASs are used in many industrial sectors and products; they are also of growing importance due to their related health risks and long-term effects in the environment.
Advantages of the analysis of the sum parameter EOF
Due to the numerous unknown PFAS compounds, single-substance analysis cannot provide an accurate estimate of the risk potential in certain circumstances. Irrespective of ongoing standardisation work, sum parameters provide valuable additional information about the magnitude and geographical distribution of PFAS contamination in soil and water. This holistic evaluation makes it possible to take comprehensive measures to control contamination and reduce risks.
What is the difference between AOF and EOF?
AOF (adsorbable organically bound fluorine) and EOF (extractable organically bound fluorine) differ significantly in their goals and methodology for the measurement of organic fluorine compounds in environmental samples. AOF aims to identify compounds that can adsorb on activated carbon and typically involves hydrophobic or less polar structures.
Complete picture of contamination by organic fluorine compounds
In contrast, EOF focuses on the measurement of organic fluorine compounds that can be extracted from solid matrices such as soil or sediments using specific solvents. These compounds often have a high polarity that increases their solubility in aqueous or organic solvents. As such they are more available biologically and more relevant ecologically, which makes them important indicators for the mobile, bioactive fraction of fluorine contamination. The differences between AOF and EOF are therefore fundamental, because they highlight different aspects of the behaviour and the effects of fluorine compounds in the environment. Both of these parameters are essential to obtain a complete picture of the contamination and the risk due to organic fluorine compounds, including PFASs and non-PFAS compounds with similar physicochemical characteristics.
Summary: EOF
The sum parameter EOF provides information about the extractable organic fluorine compounds in a sample and plays a central role in environmental analytics. It supplements the direct measurement of specific compounds and offers a quick estimation of the contamination, which is indispensable for effective environmental analyses and management.
