An improved method and apparatus for radiopharmaceutical purification, the apparatus including a chromatographic separating device, a UV-absorption detector, a radioactivity detector and a collection container having a collection inlet valve located at a collection location. Propagation times of eluent between the UV-absorption detector and the radiation detector, as well as between one or both of the detectors and the collection inlet valve, are determined. UV-absorption and radiation data from the detectors are monitored, and an appropriate time period during which the collection valve should be opened is established. Preferably, monitoring and operation of the apparatus is under control of a computer. A user interface display may be provided to enable an operator to monitor the purification process, and to intervene as required and/or appropriate.