Alginic Acid

Alginic acid is a linear copolymer with homopolymeric blocks of (1-4)-linked ?-D-mannuronate (M) and its C-5 epimer ?-L-guluronate (G) residues, respectively, covalently linked together in different sequences or blocks. The monomers can appear in homopolymeric blocks of consecutive G-residues (G-blocks), consecutive M-residues (M-blocks), alternating M and G-residues (MG-blocks), or randomly organized blocks. Molecular weight varies from 10,000 to 600,000. Analysis is a challenging task due to a wide distribution of molecular weights. Alginic acid analyzed in ion-exclusion and size exclusion mode on Primesep C mixed-mode cation exchange column. Alginic acid elutes before void as a single peak with good symmetry. Method can be used for quantitation of alginic acid in various formulation. Low UV or ELSD can be employed.

Alginate is used in various pharmaceutical preparations. Chemically, it is a linear copolymer with homopolymeric blocks of (1-4)-linked ?-D-mannuronate (M) and its C-5 epimer ?-L-guluronate (G) residues, respectively, covalently linked together in different sequences or blocks. Alginic acid can be separated from benzoate, citric acid and saccharin by mixed-mode chromatography on Primesep C HPLC column. This method can be used to quantitate alginic acid, citric acid or saccharin in complex mixtures. Various detection technique can be used (UV, ELSD, LC/MS), based on mobile phase selection.