Development and validation of capillary electrophoresis for the determination of selected metal ions in airborne particulate matter after sequential extraction

A capillary electrophoresis (CE) method has been developed and validated for the determination of the distribution of metals in particulate matter after three-stage sequential extraction. Fe(II), Zn(II), Cu(II), Mn(II), and Cd(II) ions were separated using a background electrolyte consisting of 200 mmol L(-1) ammonium acetate (pH 5.5), 0.5 mmol L(-1) 1,10-phenanthroline, 10 mmol L(-1) hydroxylamine hydrochloride, and 20% acetone. The method was validated with respect to specificity, linearity, detection limits, precision, and accuracy. Detection limits are at sub-microg L(-1) levels (tens of microg g(-1) of particulate matter) using pressure injection. The analytical procedure was checked by analyzing a standard reference material, NIST SRM 1648 Urban Particulate Matter.