Quantitative imaging of trace elements in brain sections of Alzheimer’s disease mice with laser ablation inductively coupled plasma-mass spectrometry

Abstract Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has become a powerful technique for imaging of trace elements in biological samples. However, accurately quantitative imaging is still a complicated task due to lack of matrix-matched standard materials. On the other hand, traditional LA-ICP-MS analysis usually suffers from slow analytical speed and low imaging resolution mainly due to a long washout time of an ablation cell and a low repetition rate of a laser. In this work, a series of homemade matrix-matched standards were produced by homogeneous spiking of gelatin with a known amount of trace elements (Fe, Cu, and Zn). Using these standards, quantitative imaging of Fe, Cu, and Zn in the brains of Alzheimer's disease (AD) and control mice were achieved using a laser ablation system with a low-dispersion cell and a high repetition rate laser coupled to a triple quadrupole ICP-MS. The limits of detection of Fe, Cu, and Zn are 5.4 μg g−1, 0.081 μg g−1, and 0.54 μg g−1, respectively. The concentrations of Fe, Cu, and Zn in mouse brains are 10 ∼ 70 μg g−1, 5 ∼ 30 μg g−1, and 25 ∼ 150 μg g−1, respectively. The quantitative imaging shows different distribution and contents of these metals between AD and control mouse brains. The developed LA-ICP-MS approach is expected to provide a new insight into biological effects of metals and aetiology of metal-related diseases.