Determination of nitrilotriacetic acid in waste and natural waters

An analytical method and the method validation for the determination of NTA in waste waters and in the aquatic environment is presented. An aqueous sample, after evaporation to dryness, was treated with an ethyl esterification reagent. The resulting ester was identified by MS and determined by GC-NPD apparatus. The response was linear within realistic scale (0.006 mg/l—50 mg/l) for lake and waste waters. The recoveries were found to vary between 105 and 123 % for lake water and between 113 and 124 % for waste water. The run-to-run repeatabilities and reproducibilities were all below 2.1 %. revealing the high precision of the method. The detection limit was 6 μg/l and quantitation limit 13 μg/l. No interferences were observed.