ABSTRACT
This chapter is the first devoted to the methods of separation. It deals with the separation of a mixture of distinct phases that contain the solutes to analyze and most often for this purpose, must be separated and isolated. Three cases are evoked. The first one concerns the separation of solid phases. It is only mentioned very briefly the historical separation of the tartrates left and right by Pasteur and the mechanical means of levigation widely used in the mining industry. The second case concerns the separation of solid and liquid phases. Two processes are investigated; one briefly, because it is well-known filtration and the other slightly more in length, that is centrifugation. For the first process, some qualities of porous membranes which are in use are recalled. The centrifugation is presented on the basis of an elementary equation giving the modulus of the centripetal (and of the centrifugal) force. The salient characteristics of the method are given. The last point retained in this chapter is the case of mixtures of liquid phases. We confine ourselves to describing the general means which is mechanical with a decantation funnel and to recall how to preclude the formation of the emulsion.
