Chelation ion chromatography as a technique for trace elemental analysis in complex matrix samples

A new method for the determination of lanthanides based on chelation and ion chromatography with absorbance detection is described. gamma-Aminobutyrohydroxamate resin or its derivative, N-methyl-gamma-aminobutyrohydroxamate resin in a column was used to concentrate and separate lanthanides from the alkali and alkaline earth metals and other matrix components. Various complexing agents were investigated as possible eluants. The influence of a sample matrix and parameters important for quantitative analysis are discussed. Using gamma-aminobutyrohydroxamate resin as concentrator, and potassium nitrate (0.02 M) as matrix eliminator, with the mobile phase of oxalic acid (0.03 M, pH 4.5)-diglycolic acid (0.005 M), and 4(2-pyridylazo)resorcinol (6x10(-5) M)-ZnEDTA(1x10(-4)M) as postcolumn reagent, most of the lanthanides can be separated and determined in the complex matrix samples. The detection limit was found to be 2.5 ng ml(-1) for these elements by concentrating 25 ml of sea water.