Atomic fluorescence spectroscopy

What is AFS analysis used for?

AFS can detect metallic elements in a wide variety of sample types. It is most commonly used to measure levels of toxic heavy metals in food, water, and environmental samples. The applications of atomic fluorescence spectrometry also extend to biomedical testing, where the method can be used to test for metals in blood and urine samples.

In mining and metallurgy, AFS is used to determine metal concentrations in ore samples, helping to evaluate ore quality before mining. The method may also be used to screen for lead and other contaminants in fuel testing.

How does atomic fluorescence spectroscopy work?

In AFS, samples are first converted into a gas using an ionization method, such as exposure to a flame or other heat source. The atomic gas that forms is then exposed to visible or ultraviolet light of a specific wavelength. This light will interact with atoms of a specific element, causing them to fluoresce. The fluoresced light is then picked up by a detector, which in turn can calculate the concentration of that specific element. By repeating this process and testing for different elements, it is possible to determine the elemental makeup of the sample.

Sample requirements and preparation

Atomic fluorescence spectroscopy is usually conducted on samples that are converted into an atomic gas from a solvent phase. This means that the sample must be in the form of a liquid or solution prior to analysis. Solid samples will need to be dissolved in a suitable solvent. Samples may also require pre-treatment to remove contaminants that could affect the results.

Advantages of atomic fluorescence spectroscopy

The main advantage of AFS is its high specificity; it can observe specific elements even in very low concentrations, which makes it ideal for detecting trace amounts of toxic metals. A wide variety of different metals can be detected, which makes AFS a versatile testing method. It is also a relatively simple method, meaning that samples can be tested quickly with high throughput.

Limitations of AFS analysis

AFS can only detect one element at a time, which slows the process down when the sample contains multiple elements of interest. In such cases, ICP-OES or ICP-MS might be preferable.

AFS mostly works with metal atoms and therefore has limited use in organic and other non-metal-based chemistries. Furthermore, some compounds can create interference with the fluorescence effect, thus it is not a suitable method for all samples. Finally, AFS is a destructive method, meaning that the sample is effectively destroyed during the atomization process and cannot be recovered after analysis.

What is the difference between AFS and AAS?

Atomic absorption spectroscopy (AAS) is a similar technique in which atomized samples are exposed to specific wavelengths of light to determine their elemental makeup by observing which wavelengths are absorbed and therefore which atoms are present. AAS typically requires less expensive equipment than AFS and is therefore more widely accessible.

However, AFS often has a lower detection limit and reduced background noise, which makes it more valuable when detecting certain metals in trace amounts.

Questions?

Chemical testing expert Meeri Rantanen is happy to help with queries relating to AFS and other elemental analysis methods.

meeri.rantanen@measurlabs.com+358 50 313 1948

Need an elemental analysis?

Measurlabs offers high-quality elemental analyses with AFS and various other methods, including ICP-OES and ICP-MS. Check out, for example, our single-element analysis, which can be used to detect the chosen element (often mercury) in water and other environmental samples. If you wish to discuss your testing needs in more detail or request an offer for a wider set of elements, do not hesitate to contact us.

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