A new method for the determination of complexing agents in river water using HPLC

 An HPLC-method is described for the rapid and sensitive determination of NTA, EDTA and DTPA in surface and ground water at the sub-μg/L level. The analytes are enriched on anion-exchange cartridges, eluted with formic acid and analyzed on RP 8 columns within 6 min. Recoveries for EDTA and NTA were 110% resp. 94% at an interlaboratory test. They are significantly lowered when higher amounts of sulfate are present in the sample. Reproducibility and comparability with other methods are investigated. The new technique is faster than the well known GC-analysis. Received: 11 March 1996/Revised: 10 June 1996/Accepted: 21 June 1996