The present invention provides an adsorbent for removing water and/or other oxygen-containing impurities from a fluid comprising ammonia to the ppb level and methods for making and using same. The adsorbent preferably comprises a substrate having a plurality of pores and a surface area that ranges from about 100 to about 2,500 m.sup.2/g and a compound disposed within a least a portion of the substrate. In certain preferred embodiments, the compound comprises at least one cation from the group consisting of ammonium (I), lithium (I), sodium (I), potassium (I), cesium (I); magnesium (II), calcium (II), strontium (II), barium (II), manganese (II), nickel (II), iron (II), zinc (II); aluminum (III), indium (III), iron (III), and zirconium (IV) or combinations thereof that is ionically associated with an anion from the group consisting of halide, sulfide, sulfite, or sulfate.