(99%), nitric acid (70%), tetraethylammonium chloride (98%), tetraethylammonium
nitrate (99%), and tetraethylammonium hydrogen sulfate (99%) were
purchased from Acros Organics (Geel, Belgium). Co, Sm, and Ga standard
solutions (1000 ± 10 mg L–1) were purchased
from Chem-Lab (Zedelgem, Belgium). Acetonitrile-d3 (99.9%), Triton X-100 (for molecular biology), and 1-ethyl-3-methylimidazolium
chloride (>95%) were obtained from Sigma-Aldrich (Diegem, Belgium).
Cyanex 923 was purchased from Solvay (Vlaardingen, Netherlands). Isopropanol
(analytical reagent) and LiCl (analytical reagent grade) were supplied
by Fisher Scientific (Merelbeke, Belgium). SmCl3·6H2O (99.9%) was ordered from Strem Chemicals (Newburyport, MA).
A silicone solution in Isopropanol for the treatment of the TXRF quartz
glass carriers was obtained from SERVA Electrophoresis GmbH (Heidelberg,
Germany). Choline chloride (98%) was purchased from J&K Scientific
(Pforzheim, Germany). 1-Butyl-1-methylpyrrolidinium chloride (99%)
was obtained from IoLiTec (Heilbronn, Germany). Tetraethylammonium
bromide (99%) was ordered from J. T. Baker Chemicals (Deventer, Netherlands).