The ratio of lactulose/mannitol excretion in urine after their administration is of great importance for evaluation of malabsorption and intestinal permeability disruption in some diseases. An analytical method has been developed for determination of lactulose and mannitol in urine on the same amino HPTLC plate. The method enables densitometric quantification of lactulose by use of fluorescence mode, and mannitol by use of absorption mode after detection with AgNO
, Acta Anaesthesiol. Scand.