Evaluation of metal distributions in small samples of mouse brain lesions (hematoma) by inductively coupled plasma mass spectrometry after sampling by laser microdissection (LMD)

Laser microdissection (LMD) used for sample preparation was combined off-line with inductively coupled plasma mass spectrometry (ICP-MS) to evaluate metal distributions in mouse brain with hematoma lesion. Small amounts (from 0.014 to 0.338 mg) of tissue were sampled from selected regions of the brain, with a hematoma lesion and also from regions without hematoma. The obtained samples were decomposed in closed vessel in a microwave oven and a micronebulizer in conjuction with a desolvation system was used for introducing the solution of the sample into the plasma. Accuracy was evaluated using certified reference materials (bovine liver and mussel tissue), whilst the agreement between the concentrations found with those certified was better than 85%. The limits of detection (LODs) of Cu, Fe and Zn for the small mouse brain tissue samples were 12.4, 12.5 and 9.6 μg g−1, respectively. The LODs of K and Na were 1.07 and 0.24 mg g−1, respectively. The distribution of K, Na, Cu, Fe and Zn in the selected regions of the mouse brain was evaluated. It was observed that the Fe, Na and Zn concentrations were approximately 2–10 times higher in the hematoma region (inside and around the hematoma) than in the control (region without hematoma). The LMD system demonstrated to be useful for sampling small amounts of biological tissue from regions of interest for further analysis by ICP-MS.

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► Metal distributions were evaluated in mouse brain lesion (hematoma).
► ICP-MS was employed for quantitative K, Na, Cu, Fe and Zn determination after micro-sampling of biological tissues by laser microdissection (LMD) and digestion.