Molecular weight refers to the mass of a molecular relative to its constituent elements. Material's properties, such as mechanical properties, rheological properties, are influenced by its molecular weight and molecular weight distribution. Molecular weight plays an important role for material development, material selection, quality control during material processing. It is one of the basic data required for the study of specific polymerization reactions and the structure of specific polymers in the fields of polymer chemistry and polymer physics. In addition, molecular weight is also a primary parameter in the identification of biological samples such as proteins, peptides and polysaccharides.