Abstract: The sucrose content of raw sugar, white sugar, some speciality sugars and plantation white sugar is determined by polarimetry in the visible (VIS) wavelength range (540 nm to 633 nm) and expressed in °Z of the international polarimetric sugar scale.
The international polarimetric sugar scale is exactly valid only for solutions of pure sucrose in water.
Deviations from the true sucrose content depend on the amount and kind of impurities.
Following this method, typical impurities are eliminated as far as possible by clarification using lead acetate.
The method is Officially adopted and may form the basis of sugar purchasing contracts.
The absolute difference between two results obtained under repeatability conditions should be not greater than 0.10 °Z.
The absolute difference between two results obtained under reproducibility conditions should be not greater than 0.25 °Z.
Precision data are determined and valid only for raw sugar in the range of 97.6 °Z to 99.98 °Z.
The method was assigned Official (Reference) status.
It is the method that ICUMSA® recommends for the determination of the Polarimetric Sucrose Content of Raw Sugar in preference to Method GS1-2.
Online Access to ICUMSA Method GS1-1 (2022)
Access to the online Version of ICUMSA Method GS1-1 (2022) can be obtained from the Sugar Industry Website, operated by Bartens. The online access for two years costs EUR35 (+ 19 % VAT for German and EU citizens without EU VAT No.).