Selection of a suitable buffer for ICUMSA color determination at pH = 6.4.

摘要

It has been recommended that the ICUMSA analytical technique for determination of sugar colour be carried out at pH 6.4 rather than pH 7.0. This study examined the suitability of 3 different buffers (MES, MOPSO and MOPS) to stabilize pH of sugar solutions at pH 6.4. Turbidity was minimized using cellulose ester filters with a pore size of 0.80 mum followed by 0.45 mum. MES (2-(N-morpholino) ethanesulfonic acid) buffer showed good pH stabilization at pH 6.4 and limited colour change. On the basis of these preliminary investigations, it is suggested that MES buffer be used for pH adjustment during ICUMSA collaborative testing of all types of sugar colour according to the IUPAC (International Union for Pure and Applied Chemistry) protocol.