The development and quality assessment of biopharmaceuticals, especially protein and peptide drugs, require a series of analytical techniques to assess the integrity of bioactive molecules during formulation and administration. MALDI-TOF-MS provides accurate mass measurement and high-throughput analysis of intact biomolecules ranging from 1 to 100 kDa. This technique can reveal detailed structural information at the molecular level through ion fragments of small molecule samples in 5 minutes. Compared to ESI-MS technology, MALDI-TOF produces fewer multi-charged ions and allows full-spectrum analysis of protein samples without additional deconvolution steps.