An improved colorimetric method for the estimation of lactulose in lactose-lactulose mixtures.

An improved colorimetric method is described for the estimation of lactulose in
mixtures of lactose and lactulose. The anthrone method for the estimation of
lactulose was modified by altering the concentrations of alcohol and acetic acid
added to the reaction mixture• This resulted in a two-fold increase in the sensitivity
of the method and also facilitated increase in sample volume. Values for lactulose
estimated in lactose-lactulose mixtures using this method, compared well with
those obtained using a chromatographic method involving a prior separation of
lactulose.