title: Quantitative chromatographic method for the determination of low levels of nitrilotriacetic and ethylenediaminetetraacetic acids in diethylenetriaminepentaacetic acid.
abstract: A quantitative method for determination of low levels (0.05%, w/w) of nitrilotriacetic and ethylenediaminetetraacetic acids in diethylenetriaminepentaacetic acid is described. Palmitic acid is added to the chelator as an internal standard before esterification with methanol containing 2%(v/v)H2SO4. The methyl esters of palmitic, nitrilotriacetic, and ethylenediaminetetraacetic acids are first separated from diethylenetriaminepentaacetate by silicic acid column chromatography and are subsequently quantitated by gas-liquid chromatography. The method is both accurate and reproducible with less than 10% relative error. Thin-layer chromatographic separations of the methyl esters, and quantitation at the 1% level, are also described.
mesh_terms: D000085:Acetates / Q000032:analysis*; D002849:Chromatography, Gas; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D004340:Drug Contamination / Q000032:analysis; D004492:Edetic Acid / Q000032:analysis*; D009571:Nitrilotriacetic Acid / Q000032:analysis*; D004369:Pentetic Acid / Q000032:analysis*
chemical_list: D000085:Acetates; D004369:Pentetic Acid; D004492:Edetic Acid; D009571:Nitrilotriacetic Acid