Preparative separation chromatograph system

A preparative separation chromatograph system having a column for temporally separating components in a sample and for discharging an eluate fluid with the components, a detector for obtaining an absorbance spectrum A(λ) of the eluate fluid, and a fraction collector for continuously creating a chromatogram S(t) in real time based on the absorbance spectrum A(λ) and for fractionating the eluate fluid based on the chromatogram S(t) to separately collect a target component, the system further comprising:

• a) a peak section determiner for determining whether or not a chromatogram peak of the target component is present based on the chromatogram S(t);
• b) a differential value calculator for calculating a differential spectrum value A′(λ0)=d(A(λ))/dλ|λ=λ0 which is a value of a wavelength differential d(A(λ))/dλ of the absorbance spectrum A(λ) at a known wavelength λ0 at which an absorbance of the target component has a local maximum or local minimum value;
• and
• c) a fraction collector controller for controlling the fraction collector so as to fractionate the eluate fluid based on results of a determination by the peak section determiner and a calculation by the differential value calculator.