Measurement of the optical rotation for solutions of sugars and amino acids using a simple polarimeter

10% solutions of the sugars and amino acids are supplied. Each will be used to give a solution of length 10 cm/ 20 cm for use in the polarimeter. To ensure a length of 10 cm make sure that the tube is filled ALMOST to the brim. To carry out these measurements, make sure you use the special polarimeter tubes provided.

Record the values of the optical rotation obtained for the 10% solutions and hence identify them in the table below. Note that these values are 1/10th the specific rotation as they are only 10% solutions, i.e. 0.1 g/mL solutions.

polarimeter test

D-glucose = 11

d-fructose = 12

d+galactose = 21