The determination of part-per-billion levels of citric and nitrilotriacetic acids in tap water and sewage effluents

Abstract

Citric and nitrilotriacetic acids can be determined at the 1–10,000 p.p.b. 1 1 Throughout this article the American (10 9) billion is meant. levels in aqueous systems ranging from tap water to sewage effluents by use of anion-exchange clean-up, derivatization with butanol—HCl and gas chromatography. A variety of metals present at legal tolerance limits do not interface. The two esterfied acids separate well on a special gas chromatographic phase; however, citric acid can also be separated from nitrilotriacetic acid by ion exchange prior to derivatization, if so desired.