Impurity analysis of ultra-high-purity materials—such as high-purity semiconductors, specialty alloys, and advanced ceramics—faces core challenges of extremely low concentrations (often below ppm levels) and the lack of reliable matrix-matched reference materials. We address this challenge by employing femtosecond laser ablation ICP-MS (fsLA-ICP-MS) combined with our proprietary "solid standard addition" technique. The principle of this method involves uniformly mixing or layering solid reference materials of known concentration with ultra-high-purity sample powders at precisely controlled ratios to prepare calibration series. Throughout this process, the total laser ablation amount is maintained constant for each calibration point and sample point, thereby establishing a calibration curve with minimized matrix effects. The advantage of this technology lies in the fact that both calibration standards and samples are in solid form with highly consistent physical and chemical properties, completely eliminating matrix mismatch errors inherent in traditional liquid calibration methods. Ultimately, we achieve precise localization and quantification of trace and ultra-trace impurity elements from ppb to sub-ppb levels under conditions most representative of actual analytical scenarios, providing critical data support for quality control, process improvement, and failure analysis of ultra-high-purity materials.