The present invention is directed to an apparatus for combining a component from a fluid composition with a reactive fluid. The apparatus includes a hollow fiber contactor (142) having a plurality of hollow fibers contained within a housing. A reactive fluid (224), which may be on the shell or lumen side of the hollow fiber membrane, is included in the apparatus and is used for combining with a component from a fluid composition which is on the opposite side of the membrane from the reactive liquid. The reactive liquid combines with one or more components from the fluid composition and can be used for purification of the fluid composition or for the preparation of chemical reagents.