Rapid speciation of iron by on-line coupling of short column capillary electrophoresis and inductively coupled plasma mass spectrometry with the collision cell technique

A method for rapid speciation analysis of iron was developed by on-line coupling of short column capillary electrophoresis and inductively coupled plasma mass spectrometry. The collision cell technique was used to eliminate argon-based polyatomic interferences and a Micromist nebulizer was employed to increase the nebulization efficiency. Rapid speciation analysis of Fe(II) and Fe(III) was achieved within 1 min by short column capillary electrophoresis in a 14 cm x 50 microm id capillary at 28 kV voltage with a mixture of 15 mmol/L tris(hydroxymethyl)aminomethane + 1 mmol/L 1,10-phenanthroline + 1 mmol/L EDTA (pH 8.6) as running electrolyte. The precisions (RSD, n = 5) of migration time and peak area for Fe(II) and Fe(III) were in the range of 1.0 - 2.6 and 1.9 - 3.9%, respectively. The limits of detection (3sigma) of Fe(II) and Fe(III) were 10.0 and 8.3 microg/L, respectively.