Determination of mono and disaccharide content of enteral formulations by gas chromatography

A quantitative GC method has been developed which allows determination of mono and disaccharides in enteral formulations. The method is based on the isolation of the mono and disaccharide fraction on a charcoal-celite column and conversion to trimethylsilylated oximes (TMS-oximes). The repeatability of the complete method and recovery were acceptable. in the five commercial samples assayed, maltose was the main sugar (5.24 - 8.85 g L-1) followed by glucose (1.06 - 2.41 g L-1) and lactose (0 - 1.17 g L-1). Low levels of fructose (0 - 0.18 g L-1) and sucrose (0 - 0.07 g L-1)were observed and galactose was detected in two of the samples. The presence of maltulose is reported in enteral formulations for the first time. Maltulose formed from maltose during processing, was present in variable amounts (0.12 - 1.07 g L-1) and could be a useful indicator for enteral formulation classification.