Abstract: Liquid chromatography apparatus includes a solvent mixer which comprises a tapering or conical enclosed chamber (21) having an inlet (22) adjacent its larger end and an outlet tube (23) which extends through the base of the chamber (21) and has its open end adjacent to the apex (25) of the chamber. The mixing action takes place as the shape of the chamber (21) and position of the inlet (22) causes the liquid to shear in layers as it rotates up the chamber wall from the larger to the smaller end. The shear causes a good mixing action without requiring any movable devices within the chamber to stir the liquid.

Abstract: A liquid chromatograph apparatus comprises a plurality of solvent sources (140,105) feeding a pump (102) via a proportioning valve arrangement (100). The proportioning valve arrangement (100) has a plurality of inlets (108,109) and a single outlet (110) which is coupled to the inlet coupling (112) of the pump (102). The inlet coupling (112) is mounted directly on the pump head (103) and incorporates a filter (118). The pump outlet (137) is fed via a tube (138) to a chromatographic separating column. The solvent sources (104,105) are coupled to the proportioning valve inlets (108,109) via tubes (106,107) without the provision of separate filters. This gives more equal average flow rates and enables more accurate proportioning of the solvent mixture to be obtained.

Abstract: Liquid chromatograph apparatus includes a solvent mixer which comprises a tapering or conical enclosed chamber (21) having an inlet (22) adjacent its larger end and an outlet tube (23) which extends thrugh the base of the chamber (21) and has its open end adjacent to the apex (25) of the chamber. The mixing action takes place as the shape of the chamber (21) and position of the inlet (22) causes the liquid to shear in layers as it rotates up the chamber wall from the larger to the smaller end. The shear causes a good mixing action without requiring any movable devices within the chamber to stir the liquid.