The report describes an analysis of arsenic as the oxo anion. The procedure involves oxidation of the arsenic to arsenate in an aqueous solution and injection onto an anion separator column. Comparison is made with a standard wet chemical procedure, and data is presented on reproducibility. There is also a discussion of the applicability of this method to the determination of other oxo anions. In the past few years the technique of ion chromatography, as developed by Small, Stevens, and Baumann, has proven useful in a wide range of analytical applications. In particular, the determination of such species as Cl(-1), F(-1), NO2(-1), NO3(-1), SO3(-2), and SO4(-2) by anion separation column has rendered many long and complicated wet chemical procedures obsolete. In this technique the anions of interest are separated on an analytical column containing fine anion exchange particles agglomerated on surface sulfonated styrene divinylbenzene(SSS/DVB) resin. They are then passed through a strong acid stripper column from which they are eluted in a background of de-ionized water. The concentration is measured by a conductivity cell in conjunction with a strip chart recorder.