The current effective way is to intervene in the entire production process through detection methods. The earlier we intervene, the earlier we detect and screen out defective products, and the earlier we can reduce or even eliminate risks. There are currently two common methods for detecting PFAS, one is Total Fluorine-lC Screening, such as method EN 14582; The second method is gas chromatography/liquid chromatography tandem mass spectrometry (GC/MS or LC/MSMS), which optimizes sample pretreatment and analysis based on different projects and sample materials.
Selection of testing equipment and methods
(1) Regulatory data requirements
All PFAS that can be targeted for analysis have individual PFAS ≤ 0.025mg/Kg and total PFAS ≤ 0.25mg/Kg; The total fluoride content is ≤ 50mg/Kg. If it is greater than 50mg/Kg, proof should be provided to the law enforcement department to clarify the PFAS content.
(2) Testing equipment and methods
The more economical and practical detection method is to prioritize screening the total fluoride content threshold of 50mg/Kg, that is, the total fluoride screening method. If it is greater than 50mg/Kg, GCMS and LC-MS/MS methods are required to qualitatively and quantitatively confirm each component.
The detected fluoride ions come from fluoride, which includes PFAS and other fluorine-containing substances; When converting the fluoride ion content back to PFAS content, it is based on the fact that all fluoride ions come from PFAS, so the screening results are often greater than or equal to the actual PFAS content. Therefore, the laboratory can set a safety limit based on the actual situation as a risk assessment for the laboratory. For example, if the laboratory sets the PFAS safety limit to 10ppm (mg/Kg) and the fluoride ion concentration detected by screening method is converted to PFAS concentration of 10ppm, it is determined that the sample belongs to high-risk samples. GCMS and LC-MS/MS methods need to be used to qualitatively and quantitatively confirm each component.
The total fluoride screening method is suitable for the qualification determination of PFAS in low-risk and low content samples. This method is a fast and cost-effective detection method for enterprises and third-party consumer product laboratories.
(3) Comparison of Testing Equipment and Methods
|
Testing equipment and methods |
Combustion ion chromatography-IC |
Liquid chromatography-mass spectrometry LC-MS/MS |
|
Ease of Use |
The requirements for manual operation by testing personnel are relatively low. Under the premise of high automation, the requirements for sample pretreatment are simple, and there is little dependence on manual labor and testing results, which saves manpower and improves efficiency. |
The high-end laboratory analytical instruments require extremely high standards for testing personnel, as well as high requirements for supporting high-purity nitrogen gas and laboratory environment. |
|
Procurement and operating expenses |
Domestic instruments are fully capable of meeting the testing requirements. The value of the instrument is several hundred thousand yuan, and the annual operating expenses for chromatography columns, suppressors, reagents, etc. do not exceed 20000 yuan. |
At present, we still mainly rely on imported instruments. The value of the instrument exceeds one million yuan, and the operating expenses for high-purity gas, instrument accessories, and other equipment are high. Once the instrument malfunctions, the maintenance costs for each operation often amount to tens of thousands of yuan. |
|
Applicability of the method |
Not only can it be used for total fluorine screening, but it can also be used for the detection of halogens (fluorine, chlorine, bromine, iodine), with wide applicability. It can also be used for the detection of environmental samples such as wastewater and exhaust gas discharged from enterprise production. |
Mainly used for targeted analysis of PFAS, it is a specialized instrument with limited applicability. But if the data exceeds the standard, it is a necessary instrument or sent to a third-party testing institution for testing, and the testing fee for each sample is several thousand yuan. |
|
After sales service and regulations |
Localized after-sales service, almost free, can achieve rapid response and practical problem-solving. |
Once an imported brand provides on-site after-sales service, the basic labor cost is 800 yuan/hour, which does not include the material cost of replacing instrument accessories and consumables. |
|
|
Fluorine, bromine, and chlorine in electronic components. |
|