The underlying influences for the development of analytical technologies capable of accurate detection and robust quantification of trace species are very active. There are many areas of science and industry where the presence of elements at extremely low levels can have a significant impact on human health, the environment or industry [1–3,101]. As a result, requirements on analytical science are becoming increasingly demanding as the boundaries of trace analysis are constantly being pushed downwards. In response to this demand, analytical techniques have been developed to provide the required detection limits to extend the lower boundary of trace element analysis. This ‘ultra-trace analysis’ currently does not have a definition, but detection limits of elements at mass fractions of less than 10-6 and 10-8 g/g (ppm and ppb) are readily attainable, and applicable in biological applications.
The status of trace elements analysis in biological systems
Tudan, C., Weber, F., & Levine, K. (2011). The status of trace elements analysis in biological systems. Bioanalysis, 3(15), 1695-1697. https://doi.org/10.4155/bio.11.171