Dionex DX-500 Ion Chromatograph and a custom-designed Dionex concentration module with two gradient pumps is used for transition metal and rare earth element series separations. The first channel pre-concentrates and separates transition elements from anions and major elements thus completely removing interfering matrix, then a second channel separates the REE into individual elements. The DX-500 module can be used off-line or on-line with time resolved analysis (TRA).