A rotary valve analytical system comprising: a rotor having a rotor face, the rotor being rotatable about an axis perpendicular to the rotor face, wherein the rotor face has a plurality of openings, each of which is disposed at a selected radial distance from the axis, and wherein the openings extend into the rotor to form syringe barrels; a stator disposed coaxially with the rotor, the stator having a stator face in sealable, slidable rotary contact with the rotor face, wherein the stator face has a plurality of sets of openings each set of openings comprising a plurality of openings disposed at a common radial distance from the axis and each set of openings having common angular distances separating the plurality of openings therein, wherein the common radial distance of each set of openings in the stator face equals one or more of the selected radial distances of the openings in the rotor face, and wherein each opening extends as a passage through the stator to an outlet port; a rotor drive motor mechanically coupled with the rotor and adapted to cause the rotor to rotate relative to the stator; a plurality of inlet tubes, each inlet tube coupled with one of the outlet ports of the stator and adapted to deliver a fluid to the system; a plurality of outlet tubes, each outlet tube coupled with one of the outlet ports of the stator, wherein at least one opening of each set of openings of the stator is coupled with one of the outlet tubes and at least one opening of each set of openings of the stator is coupled with one of the inlet tubes; a mixer in fluid communication with each of the outlet tubes and adapted to mix fluid that enters the mixer from the outlet tubes; a sensor in fluid communication with the mixer, adapted to perform a measurement on the mixed fluids; the system characterized in that it further comprises: a plurality of plungers, one of said plungers disposed within each of the syringe barrels of the rotor; and a syringe drive motor, mechanically coupled with the plungers and adapted to drive and withdraw the plungers within the syringe barrels. a rotor having a rotor face, the rotor being rotatable about an axis perpendicular to the rotor face, wherein the rotor face has a plurality of openings, each of which is disposed at a selected radial distance from the axis, and wherein the openings extend into the rotor to form syringe barrels; a stator disposed coaxially with the rotor, the stator having a stator face in sealable, slidable rotary contact with the rotor face, wherein the stator face has a plurality of sets of openings each set of openings comprising a plurality of openings disposed at a common radial distance from the axis and each set of openings having common angular distances separating the plurality of openings therein, wherein the common radial distance of each set of openings in the stator face equals one or more of the selected radial distances of the openings in the rotor face, and wherein each opening extends as a passage through the stator to an outlet port; a rotor drive motor mechanically coupled with the rotor and adapted to cause the rotor to rotate relative to the stator; a plurality of inlet tubes, each inlet tube coupled with one of the outlet ports of the stator and adapted to deliver a fluid to the system; a plurality of outlet tubes, each outlet tube coupled with one of the outlet ports of the stator, wherein at least one opening of each set of openings of the stator is coupled with one of the outlet tubes and at least one opening of each set of openings of the stator is coupled with one of the inlet tubes; a mixer in fluid communication with each of the outlet tubes and adapted to mix fluid that enters the mixer from the outlet tubes; a sensor in fluid communication with the mixer, adapted to perform a measurement on the mixed fluids; the system characterized in that it further comprises: a plurality of plungers, one of said plungers disposed within each of the syringe barrels of the rotor; and a syringe drive motor, mechanically coupled with the plungers and adapted to drive and withdraw the plungers within the syringe barrels. a plurality of plungers, one of said plungers disposed within each of the syringe barrels of the rotor; and a syringe drive motor, mechanically coupled with the plungers and adapted to drive and withdraw the plungers within the syringe barrels.