INTRODUCTION . Ionic contamination has.lon.g been recognIzed as a primary cause of corrOSIon m steam cycle p°.wer plants. Accordingly, monitorin~ and contr°.11mg such contaminants are of great Importance m power plant operations. Dionex''s chemically s~p- pressed Ion Chromatography (IC) technology IS used worldwide to provide the required sub parts- per-billion (Ppb) level measurement sensitivity for inorganic anions in high purity water. As descrIbed below, organic acid anions are now .m°.wn to ~e a source of corrosion-causing contanllnatI~n. ThIS Application Note describes a method WhICh uses gradient IC in combination with automated sample preconcentration to determine both org.a~ic ~d inorganic anions fro~ a single ~am~le ~nJectIon. These include the anIons of major sIgnIficance: chloride, sulfate, acetate and formate; as well as additional ions such as fluoride, nitrite, bromide, nitrate and phosphate. Without gradient elution, an eluant strong e~ough to el~te s~lfat~ would cause the weakly retained org~Ic acId anlo~s and fl~o- ride to coelute in the v,oId volume. Usmg.gradient elution, all of these anIons can be determmed at I b I I ow pp eve s. 賽默飛戴安ICS-2100離子色譜系統(tǒng)