Note 204 — PART THIRD. PROCESSES FOR DETECTING AND DETERMINING SUGARS AND STARCHES AND OTHER CARBOHYDRATES IN CRUDE OR MANUFACTURED AGRICULTURAL PRODUCTS. (continued 2)
Reading edition
School of Mines Quarterly, Vols. 11 and 12.
In a later method (School of Mines Quarterly, Vol. 13, No. 3) Wiechman describes the separation of the sugars by one polariscopic and two gravimetric determinations, one before and one after inversion. The polariscopic examination is made in a ten per cent solution at a temperature of 20°. The gyrodynats of sucrose, dextrose and levulose at the temperature mentioned are fixed at 66.5, 53.5 and -81.9 respectively. The gravimetric determinations are conducted according to the methods already described. In the formulas for calculating the results a represents sucrose, b reducing sugars, x the dextrose, y the levulose, and d the observed polarization expressed in degrees angular measure. The gyrodynats of sucrose, dextrose and levulose divided by 100 are represented by s, d and l. The calculations are made from the following formulas:
(as + xd) - yl = p. (as + xd) = p + yl. xd = p + yl - as.
x = p + yl - as
d
In this calculation the gyrodynat of levulose is about ten degrees lower than that of most authorities.