https://phys.org/news/2018-07-tiny-fine-particles-global-impact.html

In recent years, the method based on the half-life of radiocarbon has been used particularly in Finland to determine the proportion of biomass in fuels – in support of bioeconomy. Typically, particle accelerators require one milligram of solid carbon to quantify the very small amounts of radiocarbon contained in samples.

"The ratio of radiocarbon in carbon is one millionth of a millionth. We are not looking for a needle in the haystack, but for the needle tip on the entire farm," illustrates Markku Oinonen, director of the Laboratory of Chronology.