Why would anyone use a flow-through monitor, if more accurate results can be obtained with longer counts of discrete samples?
A flow-through monitor gives results in real-time; there is no individual fraction manipulation required, and resolution is almost as good as that produced by the chromatography. On the other hand if fractions are collected and taken to a liquid scintillation counter, resolution is lost, each fraction must be pipetted, mixed with scintillator and placed in a counter, and results are not obtained until many hours, sometimes days, after the chromatography has been completed. In addition, discrete sample counting involves substantial additional cost — use of much more scintillator solution, the cost of counting vials, the higher cost of the instrument, appreciably greater cost of waste disposal including the counting vials, and substantial additional technician time. Most users are willing to accept the slightly reduced accuracy, or use a little additional radioactivity to increase the count rate, rather than undergo the difficulties of fraction collection.
