Quantitation of anions at parts-per-trillion levels in semiconductor pure water by means of a laboratory ion chromatograph

In the analysis of grab samples for parts-per-trillion (w/w) levels of anions, the most difficult challenge is eliminating contamination sources. This paper discusses the steps taken to identify and deal with these problems. Areas addressed include instrument configuration and assembly, preparation of standards, analysis of standards, and water purification. Precision and accuracy data from the system are given. A Dionex 4000i unit was utilized for all work.