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 mold-prepared 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., Pb2+, Cd2+) in the metabolic process of the liver.