Applying Atomic Spectroscopy in Heavy Metal Isotope Analysis – An Spectrochimica Acta Part B: Atomic Spectroscopy Review

Heavy metals in water pose an enormous threat to human health and food safety (1). Analytical techniques have been deployed to conduct heavy metal isotope analysis, with the goal being to assess if a water source is safe for human consumption. In a recent review article published in Spectrochimica Acta Part B: Atomic Spectroscopy, authors evaluate the progress atomic spectroscopy has made in heavy metal isotope analysis (1).

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Atomic spectroscopy can be done in real-time with high resolution and has promise in heavy metal isotope analysis in biomedicine, nuclear fuels, and environmental monitoring (1). In this review article, the authors reviewed linear spectroscopic methods (such as atomic emission, atomic absorption, and laser-excited atomic fluorescence spectrometry) and non-linear spectroscopic methods (saturated absorption spectrometry, four-wave mixing spectrometry, and Doppler-free two-photon spectrometry). Atomic spectroscopy can be separated by these two categories because of the interaction between the light field and medium (1).

The authors also discussed the principles of the abovementioned spectroscopic methods, examining their benefits and drawbacks in isotopic analysis (1). Linear spectroscopic methods analyze the intensity of photons emitted or absorbed by atoms to get the sample material component information (1). Atomic emission spectroscopy is based on the fluorescence intensity of the emission of atoms in high-energy levels and is one of the widely used methods for qualitative and quantitative isotope analysis (1). Atomic absorption spectroscopy, meanwhile, is based on the atom absorption of photons (1).

Ultimately, the authors conclude that atomic spectroscopy is not quite there yet when it comes to heavy isotopic analysis. Although atomic spectroscopy has been applied to most heavy metal composition analysis, isotope analysis focuses mainly on heavy elements, such as lead, copper, mercury, uranium, silver, cadmium, and chromium, elements that are still better detected with mass spectrometry (1).

Atomic spectroscopy offers many benefits to the analyst, but it still requires better accuracy and precision (1).

Reference

(1) Zhang, M.; Song, H.; Shang, J.; et al. Spectroscopic methods for isotope analysis of heavy metal atoms: A review. Spectrochim. Acta Part B: At. Spectrosc. 2023, 207, 106740. DOI: 10.1016/j.sab.2023.106740