A methodology based on species-unspecific isotope dilution-gel electrophoresis-laser ablation cou-pled with inductively coupled plasma mass spectrometry( GE-LA-ID-ICP-MS) was established for the absolute quantification of proteins in human serum by measuring sulfur. The electrophoresis separation condition of hu-man serum were 7. 5% separating gel, 4% stacking gel, 100 V until bromophenol blue dye had migrated to the bottom of gel. The average signal intensity of 32 S at different concentrations of sulfur enriched gels(1-400μg/g) showed a good linear relationship. The relative quantitative analysis of transferrin and albumin in hu-man serum was investigated using external standard method. In addition, the created species-unspecific iso-tope dilution in GE-LA-ICP-MS had added 34 S spike signals into gels successfully by mixing sulfur spike with protein strips. According to isotope dilution equation, the method was applied to a fast, accurate absolute quantification of transferrin and albumin in human serum. The methodology was validated by comparing with the quantitative analysis of a serum protein certified reference material( ERM-DA470/IFCC) . The results con-firmed that determined concentration of transferrin and albumin fitted well with the certified value and the methodology had good accuracy and better measurement precision than external standard method.%建立了聚丙烯酰胺凝胶电泳( PAGE)-激光烧蚀进样电感耦合等离子体质谱( LA-ICP-MS)与非特异性同位素稀释法联用技术，通过测定蛋白条带上硫元素的含量，实现了人血清中蛋白的定量分析.血清电泳分离条件为：分离胶浓度(质量分数)为7.5%，浓缩胶浓度为4%，电泳电压100 V.为优化激光烧蚀实验条件，以LA-ICP-MS测得不同浓度硫富集凝胶中32 S的信号强度，在1~400μg/g范围内呈现良好的线性关系， R2=0.993.采用外标法对血清中的转铁蛋白和白蛋白进行了相对定量分析.此外，重点采用“电泳后同位素稀释”方法实现了蛋白条带上34 S稀释剂的加入，对血清中转铁蛋白和白蛋白进行了绝对定量分析；采用人血清蛋白标准物质ERM-DA470/IFCC对建立的方法体系进行了验证，结果表明2种蛋白的定量结果与标准值吻合，方法的准确性好，且测量精度优于外标法.
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