STUDY OF ISOTACHOPHORETIC SEPARATION BEHAVIOR OF METAL-CATIONS BY MEANS OF PARTICLE-INDUCED X-RAY-EMISSION .6. SELECTIVE SEPARATION OF 20 METAL-CATIONS USING TARTARIC ACID AS A COMPLEXING AGENT

The selective isotachophoresic (ITP) separation of twenty metal ions that form kinetically labile complexes with tartaric acid was investigated. The leading electrolyte was 20 mM ammonia solution buffered by adding acetic acid (pH 4.8) and the concentration of tartaric acid (C-Tar) was varied in the range 0-5 mM. The terminator was 20 mM carnitine hydrochloride solution. Isotachophoretic qualitative indices (R(E)) of the metal ions were measured by using a high-frequency contactless conductivity detector. An equimolar test mixture was separated by using a micro-preparative apparatus and the fractions were analysed off-line by particle-induced X-ray emission method (ITP-PIXE). When C-Tar = 1 mM, the separability was good on average. The migration order was Ba2+, (Sr2+, Na+), Ca2+, Mg2+, Mn2+, Fe2+, Co2+, Cd2+, (Ni2+ Li+), Zn2+, La2+, (Ce3+, Pb2+), Y3+, Gd3+, Lu3+, Cu2+, where the ions in parentheses were not separated. Zr-IV O2+ was not detected. With increase in C-Tar, the number of detectable elements decreased owing to the decrease in the effective mobilities of the separands. When C-Tar = 5 mM, the migration order was Na+, Ba2+, Sr2+ Mg2+, Li+, Ca2+, Mn2+, Cd2+, Co2+, Ni2+ and Zn2+. A model waste from a nuclear fuel was successfully analysed using the electrolyte system.