Determination of some heavy metal cations in molten snow by transient isotachophoresis/capillary zone electrophoresis

Online combination of transient ITP and CZE is employed for the determination of Cd(II), Pb(II), Cu(II), Ni(II), and Zn(II). Acetic acid is used for creating the transient isotachophoretic state. a-Hydroxyisobutyric acid and 4-aminopyridine are used as BGEs for the separation and indirect UV detection. At optimum conditions, the method allows to determine the metals at levels of 40 - 120 mu g/L, about 50 times more sensitive than conventional CZE. In combination with a 20-fold evaporative concentration, the method is suitable for environmental monitoring of the heavy metals in snow samples.