Application of chelation ion chromatography to the determination of lanthanides in agriculture

Lanthanides are widely present in soil and plant. In this paper, it is the first time that chelation ion chromatography is applied to analyse lanthanides in a series of samples in agriculture. This technique can eliminate bulk quantity of alkali, alkaline earth metals on chelating concentrator column (MetPac CC-1) and eliminate transition metals on cation exchange column (TMC-1) from complex matrices with ammonium acetate buffer while lanthanides are concentrated. It is shown to be capable of separating and determining all lanthanides on mixed-bed ion exchange column (CS5) in a wide variety of sample types with high accuracy. Elution is carried out with a concentration gradient of oxalic acid (Ox) and diglycolic acid (DGA), coupled with post-column spectrophotometric detection with 4-(2-pyridylazo)resorcinol (PAR) at 520 nm. It can determined ng ml(-1) scales of lanthanides. The whole run time after sample injection is about 55 min.