Analysis of the elemental abundance and distribution in biological tissues by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) adds to clarifying the basic questions of metabolic research and enables bioaccumulation and bioavailability studies in ecological and toxicological risk assessment. In this work, a method based on matrix-matched gelatin calibration LA-ICP-MS for the determination of essential and toxic elements in biological samples was developed. By using a moldprepared procedure, the elemental inhomogeneity distributions in the synthesized gelatin gels were improved, which was verified by using the 3D (surface-and depth-mapping) LA-ICP-MS protocols. The limits of detection (LODs) ranged from 0.014 μg g −1 (Ba) to 48 μg g −1 (K). The results of the analysis of biological reference materials (RMs) were in good agreement with the certified values. Furthermore, a reliable bio-mapping LA-ICP-MS method is proposed for studying the metabolism of heavy metals in rat liver injected with CdS/PbS quantum dots. Our results show that the high concentration of Pb and Cd co-exist (positive correlation as high as 78%) in hepatocytes and sinusoids, which indicates that the PbS/CdS quantum dots are not dissociated into toxic heavy metal ions (i.e., Pb 2+ , Cd 2+ ) in the metabolic process of the liver.