Bioimaging of uranium and thorium in mice organs by laser ablation inductively coupled plasma mass spectrometry

The spatial distribution of thorium, uranium and other radioactive elements in biological tissues is significant for evaluating their migration, toxicity and possible decorporation mechanism, however, it is still a big challenge today for developing quantitative imaging by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) due to the lack of matrix matched standards for calibration. Herein, a fast and reliable LA-ICP-MS quantitative imaging method was developed by using gelatin plus standard solution to prepare a self-made reference material containing 100 mu g/g of U and Th, overcoming the inhomogeneity of the raw animal tissue standard. Then the elemental spatial distribution of kidney and liver tissues from mice were revealed by using LA-ICP-MS method. The results showed that U accumulated mainly in the kidney and slightly in the liver, while most of Th was distributed in the liver and few of that in kidney. It was found that U and Th were heterogeneously distributed in kidney section while homogeneously distributed in liver section.

Automated summary

A self-made reference material containing 100 μg/g of U and Th was prepared by using gelatin plus standard solution, overcoming the inhomogeneity issue of the raw animal tissue standard. A fast and reliable LA-ICP-MS quantitative imaging method was developed, and elemental spatial distribution in kidney and liver tissues from mice was revealed. The results showed that U accumulated mainly in the kidney and slightly in the liver, while most of Th was distributed in the liver and only a small amount in the kidney. Heterogeneous distribution of U and Th was observed in kidney section, while a homogeneous distribution was observed in liver section.