Starches are composed of a mixture of the glucose polymers amylose and amylopectin in a ratio of about 30:70 depending on the source. Starches are primarily used as thickening agents in cooking and to provide strength in textiles and papermaking, however, the industrial applications of starches are ever increasing due to their strength, toughness and biodegradation properties. For these materials, the molecular weight distribution of the polymers determines many of their final properties and therefore the end-use suitability. Gel permeation chromatography (GPC) with Universal Calibration, employing a viscometer in combination with a differential refractive index detector, may be used to determine accurate molecular weights for biopolymers, such as starches, that are independent of the standards used in the column calibration. Two starches were analyzed using these techniques, as the thickening properties of the different samples were found to be subtly different. Agilent 1260 Infinity II 液相色譜系統(tǒng)